Description:AREA OF INVENTION
[001] The present inventions relate to biological application of pyridyl aryl/heteroaryl carbinols and their derivatives towards cancer cell lines. This invention is directed to identify small molecules which are selectively inhibiting the cancer cell lines and can be utilized for the targeted cancer therapeutics. The present inventions relate to preparation of a known/unknown pyridyl aryl/heteroaryl carbinols for cancer related medicinal applications either single active form or a combination.
[002] The derivatives of pyridyl aryl carbinols exhibited in vitro cytotoxic activities in different cancer cell lines namely lung (A549), breast (MDA MB-231), cervical (HeLa), colon (HCT-15), liver (HepG2), leukemia (K562) cancer cell lines and most of the said derivatives failed to show apoptosis in normal cell line (PBMCs). Drug lead skeleton showed anti-proliferative activity in cancer cells with minimal side effects. These compounds in accordance with the present invention can be applied in the treatment of different types of cancer. Thus, we claim to have unknown pyridyl aryl/heteroaryl carbinols, which are highly useful anticancer drug lead skeletons.

BACKGROUND OF THE INVENTION
[003] Cancer is one of the most prominent death triggering diseases and it accounts for 14% of all death in the world. Incidence of newly diagnosed cases is about 10-12 million per year and expected to double by 2030. Cancers can affect animals too. Nearly all cancers are caused by abnormalities, these abnormalities may be due to the effects of carcinogens, for example tobacco, radiation, chemicals, or infectious agents or errors in DNA replication (Wild, C.P.; Stewart, B. World cancer report 2014, International Agency for Research on Cancer. 2014.;
[004] Ferlay, J.; Soerjomataram, I.; Ervik, M.; Dikshit, R.; Eser, S.; Mathers, C.; Rebelo, M.; Parkin, D. M.; Forman, D.; Bray, F. GLOBOCAN 2012, “Cancer incidence and mortality worldwide: IARC cancer base No. 11, France: International Agency for Research on Cancer, 2013. Bray, F.; Ren, J. S.; Masuyer, E.; Ferlay, J. Global estimates of cancer prevalence for 27 sites in the adult population in 2008, Int. J. Cancer. 2013, 132, 1133-1145).
[005] Most prevention and treatment method against cancer involves the use of natural substances or their derivatives such as Paclitaxel, Colchicine, Vinca alkaloids and etoposide are the prime examples. Mass production of these molecules, and the structural modifications to reduce the side effects become inevitable. Sometimes this may lead to toxicity for the drug molecule (“The contribution of synthetic organic chemistry to anticancer drug development” Denny, W. A. Auckland Academic Press, 2002. Chapter 11, pp.188.).
[006] Significant research has been advanced on oncology and antitumor developments including chemotherapy. While assured procedures and chemical structures have been developed which aid in inhibiting, remitting or controlling the growth of tumor, for example, several anticancer agents including taxol, vinblastine, vincristine, etoposide, camptothecin and derivatives (topotecan and irinotecan), mitoxantrone, 5-fluorouracil, indomethacin, cisplatin etc. are in clinical use in all over the world.
[007] However, these drugs suffer from various side effects like low blood pressure, bone marrow suppression, gastrointestinal toxicity, constipation and hair loss (Szakács, G.; Paterson, J. K.; Ludwig, J. A.; Genthe, C. B.; Gottesman, M. M. Nat. Reviews. 2006, 5, 219-234. Schenone, M. Dancik, V.; Wagner, B. K.; Clemons, P. A. Nat. Chem. Bio. 2013, 9, 232-240).It has now been found that certain organic compounds derived from pyridyl aryl methanols possess useful biological activity.
[008] These type of carbinols generally possesses antifungal properties (fenarimol), aromatase-inhibiting activities {(4,4’-dichlorodipheny1)methane or methanol moiety} (Taylor, H. M.; Jones, C. D.; Davenport, J. D.; Hirsch, K. S.; Kress, J. T.; Weaver, D. J. Med. Chem. 1987, 30, 1359; Jones, C. D.; Winter, M. A.; Hirsch, K. S.; Stamm, N.; Taylor, H. M.; Holden, H. E.; Davenport, J. D.; Krumkalns, E. V.; Suhrt, R. G. J. Med. Chem. 1990, 33, 416-429), aryl heteroaryl methanols are important intermediates and structural motifs for various biologically active compounds, such as (R)-neobenodine, (R)-orphenadrine, (S)-cetrazine (Salvi, L.; Kim, J. G.; Walsh, P. J. Am. Chem. Soc. 2009, 131, 12483–12493). (S)-carbinoxamine (Clistin, Palgic), algetic (S)-phenyl(pyridin-2-yl)methanol (Gearien, J.; Frank, E.; Megahy, M.; Pokorny, C., J. Med. Chem. 1971, 14, 551–553).
[009] Similarly, 4-hydroxymethylacridines and its derivatives showed anticancer activity (Charmantray, F.; Demeunynck, M.; Carrez, D.; Croisy, A.; Lansiaux, A.; Bailly, C.; Colson, P., J. Med. Chem. 2003, 46, 967-977). For instance, the naturally occurring molecule indole-3-carbinol (I3C) has been reported to exhibit promising anticancer activities against a number of human cancers acting through diverse mechanisms [(a) Jin, L.; Qi, M.; Chen, D. Z.; Anderson, A.; Yang, G.Y.; Arbeit, J.M.; Auborn, K.J., Cancer Res. 1999, 59, 3991-3997; (b) Brew, C.T.; Aronchik, I.; Kosco, K.; McCammon, J.; Bjeldames, L.F.; Firestone, G. L., Int. J. Cancer 2009, 124, 2294-2302; (c) Wong, G.Y.; Bradlow, L.; Sepkovic, D.; Mehl, S.; Mailman, J.; Osborne, M. P. J. Cell. Biochem. Suppl. 1997, 28, 111-116].
[010] Therefore, the lack of effective chemotherapy for cancer is continuously inciting to explore new chemical entities for the effective and safe cure of cancer. Therefore, the pyridyl aryl/heteroaryl carbinols, diaryl carbiols have been evaluated for anti-proliferative activity. This systematic evaluation showed that they are potential in inhibiting cancer cell growth and stimulating apoptosis, which may induce cancer cell death.
[011] From the above discussion,
i. So far there is no such type of small molecules (pyridyl aryl carbinols) have been tested against cancer cell lines.
ii. Majority of the anticancer active compounds show activity in micromolar range.
iii. Very simplest indole-3-carbinol (I3C), naturally occurring, shown anticancer activity except this no such type of small carbinol derivatives have been examined.
iv. Involves multistep process to synthesize the reported drugs or drug like molecules.
v. Maximum compounds shown side effects or less affinity towards targets.
OBJECTIVE OF THE INVENTION
[012] The main objective of the present invention involves the evaluation of pyridyl aryl/heteroaryl carbinols for anticancer treatment. Another objective of the present invention is to provide unknown novel compounds to be evaluated against the cell lines. Furthermore, the present invention provides very smallest and more potent molecules (pyridyl aryl/heteroaryl carbinols) towards cancer treatment. Another embodiment of the present invention provides pyridyl aryl/heteroaryl carbinols with least side effects.
[013] The present invention proves that the pyridyl aryl/heteroaryl carbinols showing potential inhibiting cell growth and stimulating apoptosis (cancer cell death) towards the broad spectrum of cancer cells at very low concentration (1 nM). Still another objective of the present invention is to identify maximum (pyridyl aryl/heteroaryl carbinols) derivatives to show less toxic to the human cell lines and more potency towards cancerous cells.
[014] Another objective of the present invention is the development of easy accessible methods to synthesize broad range of pyridyl aryl/heteroaryl carbinols. Another objective of the present invention is, to provide an efficient and simple process for the synthesis of carbinols (pyridyl/aryl/aryl) with least drawbacks. Still another objective of the present invention is the cheaper and less time consuming protocol to obtain numerous (~0.01 million) pyridyl aryl/heteroaryl carbinols. Still another objective is functional group compatibility (ester groups, ethers etc..).

SUMMARY OF THE INVENTION
1. Accordingly, the present invention relates to usage of pyridyl aryl/heteroaryl carbinols for the treatment of various cancers.
2. This invention relates to unusual form of pyridyl aryl/heteroaryl carbinols, method of making these compound and use of these compounds in the treatment of various ailment but not limited to cancers.
3. The novel forms/compositions of pyridyl aryl/heteroaryl carbinols are synthesized via Friedel-Crafts hydroxyl alkylation process in the presence of Lewis acids.
4. The numerous innovative forms of pyridyl aryl/heteroaryl carbinols were obtained in good quantity and in one step procedure.
5. In an embodiment of the present invention, the in vitro cytotoxic activities of carbinols and their derivatives were examined.
6. Most of these molecules exhibited sub-nano molar range activity against most of the cancer cell lines examined.
7. In an embodiment of the present invention, the in vitro studies as well as mechanistic study describes these derivatives are useful for anticancer drug development.
8. Screening of derivatives were done in lung (A549), breast (MDA MB-231), colon (HCT-15), cervical (HeLa), liver (Hep G2) and leukemia (K562) cancer cells as in vitro cancer cell models and these cell lines are the representative cancer cell lines among the 60 cancer cell lines as recommended by National Cancer Institute (NCI), USA.
9. The cytotoxicity of derivatives in cancer cells and ex vivo culture of peripheral blood mononuclear cells (PBMCs) was performed by MTT reduction assay. Briefly, 1 x 105 cells were seeded in each well. After incubation for 24 h cells were treated with different concentrations of derivatives and taxol (as positive control) dissolved in dimethyl sulphoxide (DMSO) ranging from nano molar to micro molar concentrations. Control cells were treated with vehicle control DMSO. After 48 h of treatment, MTT (20 µl of 5mg/ml) was added and the plates were kept at 37 °C under dark for 3 h. Then, the media was aspirated and the MTT-formazan crystals formed inside the cells were dissolved in DMSO and the plates were read at 595 nm in ELISA plate reader. The experiments were carried out as three independent assay and each concentrations of derivatives were tested in tetrapet.
10. The inhibitory concentrations of derivatives, IC50 (concentration of derivatives to inhibit 50% of cells) was obtained from the dose-response curve of DMSO treated control cells versus different concentrations of derivatives using non-linear regression curve in Graphpad Prism software.
11. The eight derivatives, CRR-694, CRR-903, CRR-930, CRR-931, CRR-932, CRR-933, CRR-934 and CRR-935 exhibited good anticancer activity in all cancer cell lines in nano molar concentrations (Tables. 1-3) as compared to taxol having toxicity in micro molar concentrations. These derivatives displayed no cytotoxicity against normal cells.
12. All four derivatives CRR-931, CRR-932, CRR-935 and CRR-694 were used for documentation of induction of cell death through live cell and fluorescent imaging. Phase contrast imaging of control (DMSO treated) showed intact morphology whereas CRR compounds-treated cells showed dead and floating cells along with altered morphology. In order to assess the induction of apoptosis, acridine orange-ethidium bromide (AO/EB) staining assay was employed (see Figure 1 & 2). The DMSO-treated viable control cells showed uniform green colour whereas the early apoptotic cells were identified with their yellowish green colour in compounds-treated cells and the late apoptotic cells were appeared as orange to red apoptotic cells. The late apoptotic cells were distinguished from necrotic cells through chromatin condensation.
13. To assess the nuclear changes, DAPI (10 µg/ml) staining was added to cells after fixing the cells with 4% formaldehyde for 20 min (see Figure 3). After washing with PBS, the DAPI stain was added and incubated for 20min at 37 ºC. Bright condensed and fragmented nuclei in compound-treated cells were observed as compared to intact round nuclei in DMSO-control cells.
14. To determine the mitochondrial membrane potential, rhodamine 123 (Rh123) stain was used (see Figure 4). Briefly, 3 x 105 cells were seeded in 6-well plate and later treated with respective IC50 concentration CRR derivatives and DMSO. After 48 h of incubation, cells were given PBS wash and incubated with Rh123 (10 µg/ml) at 37 ºC for 20 min in dark. Then cells were washed twice and observed for imaging to cells and incubated for 20 min. Cells were washed with PBS and observed under fluorescence microscope. Treated cells showed a loss in mitochondrial membrane potential as evidenced by the diminished fluorescence in treated cells as compared to control cells.
15. To determine the generation of reactive oxygen species (ROS), 2,7-dichlorofluorescein diacetate (DCFDA) was used (see Figure 5). Briefly, 3 x 105 cells were seeded in 6-well plate and later treated with respective IC50 concentration CRR derivatives and DMSO. After 48 h of incubation, cells were given PBS wash and incubated with DCFDA (10 µM) at 37 ºCfor 20 min in dark. Then cells were washed twice and observed for imaging. The production of ROS was increased in compound-treated cells at the same exposure as compared to DMSO-control that supports the loss of mitopotential.

DESCRIPTION OF THE INVENTION
[015] To accomplish the objectives in accordance with the commitments of the invention, as embodied and fully described here, the invention comprises antitumor compositions of the general formula I-VI (Figure 6):Reference will now be made in detail to present desired embodiments of the invention, examples of which are clarified in the succeeding example section.
Wherein Ar, aromatic compounds with or without substitutions; Het.Ar, hetero aromatic compounds with or without substitutions.
[016] In accordance with the invention, derivatives according to formula I-VI are also provided but are not limited to I-VI. In accordance with the invention, a method to produce I-VI (Ref. 1. The cooperative effect of Lewis pairs in the Friedel–Crafts hydroxyl alkylation reaction: a simple and effective route for the synthesis of (±)-carbinoxamine, Harikrishnan, A.; Sanjeevi J.; Ramanathan, C. R. Org. Biomol. Chem. 2015, 13, 3633-3647; Ref. 2. Friedel-Crafts hydroxyalkylation through activation of carbonyl group using AlBr3: An easy access to pyridyl aryl / heteroaryl carbinols, Harikrishnan, A.; Selvakumar, J.; Gnanamani, E.; Suman, B.; Ramanathan, C. R. New J. Chem. 2013, 37, 563-567.)
General procedure for the addition of π-nucleophiles to pyridine-2-carboxaldehyde:

[017] An oven dried two neck round bottom flask bearing septum in side arm and fitted with condenser was cooled to room temperature under a steady stream of nitrogen gas flow. The flask was charged with stirring bar, AlBr3(1.0 mmol) and dry dichloromethane (3 mL) and cooled down to 0 °C (using ice). Then pyridine-2-carboxaldehyde (1.0 mmol) was added. The mixture was stirred for 30 minutes at 0 °C under nitrogen atmosphere. To this mixture was added dichloromethane (5 mL) solution of nucleophile (1.2 mmol) in drops.
[018] The resulting suspension was stirred at room temperature for 24 h. The reaction mixture was poured into aq. NaHCO3 and stirred for 5 min., organic layer was separated and the aqueous layer was extracted with dichloromethane (2 x 15 mL). The combined organic layer was washed with brine, dried over anhydrous Na2SO4, filtered and concentrated on rotary evaporator under reduced pressure. The residue was purified through silica gel column chromatography using hexane/ethyl acetate as an eluent to afford the pure product.
(4-ethoxyphenyl)(pyridin-2-yl)methanol (CRR-690)

[019] 190 mg, (83% yield) as yellow solid; m.p.109 ºC; IR (KBr, cm-1): 3124, 2980, 2884, 2836, 1599, 1507, 1242, 1051, 805, 754; 1H (CDCl3, 400 MHz) : δ 8.56 (d, J = 4.8 Hz, 1H ), 7.63 (td, J = 7.6, 1.6 Hz, 1H), 7.28-7.24 (m, 2H), 7.20-7.17 (m, 1H), 7.14 (d, J = 8.0 Hz, 1H ), 6.86-6.84 (m, 2H), 5.70 (s, 1H), 4.03 (q, J = 6.8 Hz, 2H ), 1.40 (t, J = 6.8 Hz, 3H); 13C (CDCl3, 100 MHz): δ161.3, 158.8, 147.8, 136.9, 135.4, 128.5, 122.4, 121.4, 114.6, 74.6, 63.5, 14.9; HRMS-ESI (m/z): Calculated for C14H15NO2 (M+H):230.1181, Found (M+H): 230.1172.
(2-ethoxy-4-methylphenyl)(pyridin-2-yl)methanol (CRR-689)

[020] 192 mg, (79% yield) as yellow solid; m.p. 72 oC; IR (KBr, cm-1): 3396, 2978, 2925, 1592, 1500, 1245, 1118, 1043, 805;1H (CDCl3, 400 MHz): δ 8.54 (d, J = 3.6 Hz, 1H), 7.61 (td, J = 8.0, 2.0 Hz, 1H), 7.33 (d, J = 8.0 Hz, 1H), 7.17-7.13 (m, 2H), 7.01-6.99 (m, 1H), 6.78 (d, J = 7.6 Hz, 1H), 6.15 (s, 1H), 5.23 (br s, 1H), 4.09-4.05 (m, 1H), 4.02-3.94 (m, 1H), 2.23 (s, 3H), 1.38 (t, J = 7.2 Hz, 1H); 13C (CDCl3, 100 MHz): δ 161.6, 154.0, 147.7, 136.7, 131.5, 130.1, 129.1, 128.5, 122.2, 121.3, 111.9, 69.7, 64.0, 20.7, 15.0; HRMS-ESI (m/z): Calculated for C15H17NO2 (M+H): 244.1293, Found (M+H): 244.1330.
(2-(benzyloxy)-4-methylphenyl)(pyridin-2-yl)methanol (CRR-697)

[021] 205 mg, (67% yield) as pale yellow semi solid; IR (KBr, cm-1): 3410, 2925, 1605, 1512, 1462, 1249, 1039, 754;1H (CDCl3, 400 MHz) : δ 8.41 (d, J = 4.8 Hz, 1H), 7.65 (td, J = 7.6, 1.6 Hz, 1H), 7.36 (d, J = 8.0 Hz, 1H), 7.19-7.13 (m, 5H), 7.09-7.07 (m, 1H), 6.91 (d, J = 1.6 Hz, 1H), 6.73 (d, J = 1.6 Hz, 1H), 5.84 (s, 1H), 3.90 (s, 2H), 2.12 (s, 3H); 13C (CDCl3, 100 MHz): δ 161.8, 150.7, 147.6, 141.3, 138.2, 131.0, 130.3, 129.1, 129.0, 128.6, 128.4, 125.8, 125.5, 123.0, 120.3, 74.5, 35.9, 20.7.; HRMS-ESI (m/z): Calculated for C20H19NO2 (M+H):306.1494, Found (M+H):306.1490.
(4-methyl-2-propoxyphenyl)(pyridin-2-yl)methanol (CRR-930)

[022] 219 mg, (77% yield) as colorless solid; m.p. 76 oC; IR (KBr, cm-1): 3386, 2929, 2873, 1586, 1499, 1467, 1245, 1045, 808, 754;1H (CDCl3, 400 MHz) : δ 8.54-8.53 (m, 1H), 7.61 (td, J = 8.0, 2.0 Hz, 1H), 7.32 (dd, J = 8.0, 0.8 Hz, 1H), 7.17-7.14 (m, 2H), 7.02-6.99 (dd, J = 8.4, 2.0 Hz, 1H), 6.78 (d, J = 8.4 Hz, 1H), 6.16 (s, 1H), 5.23 (br s, 1H), 4.00-3.96 (m, 1H), 3.91-3.85 (m, 1H), 2.23 (s, 3H), 1.82 (m, 1H), 1.02 (t, J = 7.6 Hz, 1H); 13C (CDCl3, 100 MHz): δ 161.5, 154.1, 147.7, 136.7, 131.4, 130.0, 129.1, 128.5, 122.2, 121.3, 111.7, 70.0, 69.6, 22.8, 20.7, 10.8; HRMS-ESI (m/z): Calculated for C16H19NO2 (M+H): 258.1494, Found (M+H): 258.1492.
(2-isopropoxy-4-methylphenyl)(pyridin-2-yl)methanol(CRR-692)

[023] 209 mg, (81% yield) as colorless solid; m.p. 117 oC; IR (KBr, cm-1): 3324, 2929, 2872, 1596, 1499, 1245, 1110, 1047, 808; 1H (CDCl3, 400 MHz) : δ 8.54-8.53 (dt, J = 4.8, 1.2 Hz, 1H), 7.61 (td, J = 8.0, 2.0 Hz, 1H), 7.34 (dd, J = 7.6, 0.8 Hz, 1H), 7.16-7.13 (m, 2H), 7.01-6.98 (m, 1H), 6.79 (d, J = 8.4 Hz, 1H), 6.11 (s, 1H), 5.20 (br s, 1H), 4.59-4.53 (m, 1H), 1.35 (d, J = 6.0 Hz, 3H), 1.31 (d, J = 6.0 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.7, 152.7, 147.7, 136.6, 132.4, 130.0, 129.0, 128.7, 122.1, 121.4, 113.3, 70.4, 70.0, 22.4, 22.0, 20.7; HRMS-ESI (m/z): Calculated for C16H19NO2 (M+H): 258.1494, Found (M+H): 258.1490.
 
(2-butoxy-4-methylphenyl)(pyridin-2-yl)methanol (CRR-931)

[024] 226 mg, (83% yield) as colorless solid; m.p. 103 oC; IR (KBr, cm-1): 3381, 2928, 2868, 1587, 1500, 1245, 1039, 752;1H (CDCl3, 400 MHz) : δ 8.54-8.53 (dt, J = 4.8, 1.2 Hz, 1H), 7.60 (td, J = 7.6, 1.6 Hz, 1H), 7.31 (dd, J = 8.0, 0.4 Hz, 1H), 7.16-7.13 (m, 2H), 7.01-6.99 (dd, J = 8.0, 2.0 Hz, 1H), 6.78 (d, J = 8.4 Hz, 1H), 6.14 (s, 1H), 5.22 (br s, 1H), 4.05-3.99 (m, 1H), 3.94-3.88 (m, 1H), 2.23 (s, 3H), 1.76 (m, 2H), 1.47-1.41 (m, 2H), 0.96 (t, J = 7.6 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 154.1, 147.7, 136.7, 131.4, 130.0, 129.1, 128.5, 122.2, 121.3, 111.7, 69.7, 68.1, 31.5, 20.7, 19.4, 13.9; HRMS-ESI (m/z): Calculated for C17H21NO2 (M+H):272.1651, Found (M+H): 272.1643.
(1-ethoxynaphthalen-2-yl)(pyridin-2-yl)methanol(CRR-676)

[025] 204 mg, (73% yield) as yellow solid; m.p. 116 oC; IR (KBr, cm-1): 3193, 2977, 2927, 1583, 1461, 1340, 1219, 1086, 805, 756;1H (CDCl3, 400 MHz): δ 8.54-8.53 (dt, J = 4.8, 1.6 Hz, 1H), 8.37-8.32 (m, 1H), 8.04-7.99 (m, 1H), 7.55 (td, J = 7.6, 1.6 Hz, 1H), 7.45-7.41 (m, 2H), 7.31 (d, J = 8.0 Hz, 1H), 7.21-7.18 (m, 1H), 7.06 (dd, J = 8.0, 0.4 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.31 (s, 1H), 4.22 (q, J = 6.8 Hz, 2H), 1.56 (t, J = 6.8 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.1, 147.8, 136.9, 132.3, 130.0, 127.0, 126.7, 126.5, 124.9, 124.3, 122.8, 122.4, 121.5, 103.5, 73.8, 63.8, 14.9; HRMS-ESI (m/z): Calculated for C22H24NO2 (M+H):280.1338, Found (M+H): 280.1330.
(1-propoxynaphthalen-2-yl)(pyridin-2-yl)methanol (CRR-693)

[026] 232 mg, (79% yield) as yellow solid; m.p. 113 oC; IR (KBr, cm-1): 3387, 3068, 2965, 2876, 1585, 1464, 1386, 1085, 761;1H (CDCl3, 400 MHz) : δ 8.64 (dt, J = 4.4 Hz, 1H), 8.35-8.33 (m, 1H), 8.02-8.00 (m, 1H), 7.56 (td, J = 7.6, 1.6 Hz, 1H), 7.45-7.40 (m, 2H), 7.36 (d, J = 8.0 Hz, 1H), 7.21-7.18 (m, 1H), 7.06 (dd, J = 8.0, 0.4 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.30 (s, 1H), 5.31 (br s, 1H) 4.11 (t, J = 2.4 Hz, 2H), 1.97-1.92 (m, 2H), 1.15 (t, J = 7.2 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.3, 147.9, 136.9, 132.3, 129.9, 127.0, 126.7, 126.5, 124.9, 124.3, 122.8, 122.4, 121.5, 103.8, 73.8, 69.7, 22.7, 10.9; HRMS-ESI (m/z): Calculated for C19H19NO2 (M+H):294.1494, Found (M+H):294.1492.
(1-isopropoxynaphthalen-2-yl)(pyridin-2-yl)methanol (CRR-691)

[027] 224 mg, (77% yield) as yellow solid; m.p. 110 oC; IR (KBr, cm-1):3387, 2976, 2925, 1585, 1385, 1269, 1111, 1062, 761;1H (CDCl3, 400 MHz) : δ 8.60 (m, 1H), 8.38-8.35 (m, 1H), 8.06-8.03 (m, 1H), 7.51 (td, J = 8.0, 2.0 Hz, 1H), 7.44-7.42 (m, 2H), 7.39 (d, J = 8.0 Hz, 1H), 7.14-7.12 (m, 1H), 7.09 (d, J = 8.0 Hz, 1H), 6.79 (d, J = 8.0 Hz, 1H), 6.35 (s, 1H), 5.27 (br s, 1H) 4.77-4.71 (m, 1H), 1.47 (d, J = 2.0 Hz, 3H), 1.45 (d, J = 2.0 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.6, 153.8, 147.8, 136.8, 132.4, 129.8, 127.1, 126.6, 126.5, 124.7, 124.1, 122.9, 122.2, 121.4, 105.3, 73.6, 70.2, 22.1; HRMS-ESI (m/z): Calculated for C19H19NO2 (M+H):294.1494, Found (M+H): C19H19NO2 (M+H):294.1486.
 
(1-butoxynaphthalen-2-yl)(pyridin-2-yl)methanol(CRR-694)

[028] 221 mg, (72% yield) as yellow solid; m.p. 110 oC; IR (KBr, cm-1):3384, 2951, 2870, 1583, 1464, 1385, 1271, 1087, 760;1H (CDCl3, 400 MHz): δ 8.63 (d, J = 4.8 Hz, 1H), 8.35-8.32 (m, 1H), 8.03-8.01 (m, 1H), 7.55 (td, J = 7.6, 1.6 Hz, 1H), 7.46-7.40 (m, 2H), 7.36 (d, J = 8.0 Hz, 1H), 7.20-7.17 (m, 1H), 7.01 (d, J = 8.0 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.31 (s, 1H), 5.35 (br s, 1H) 4.15 (t, J = 6.4 Hz, 2H), 1.94-1.88 (m, 2H), 1.65-1.56 (m, 2H), 1.04 (t, J = 7.2 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.3, 147.8, 136.9, 132.3, 129.9, 127.0, 126.7, 126.5, 124.9, 124.3, 122.8, 122.3, 121.4, 103.8, 73.8, 67.9, 31.46, 19.6, 14.0; HRMS-ESI (m/z): Calculated for C20H21NO2 (M+H):308.1651, Found (M+H):308.1643.
(1-(hexyloxy)naphthalen-2-yl)(pyridin-2-yl)methanol (CRR-932)

[029] 231 mg, (69% yield) as red solid; m.p. 89-91 oC; IR (KBr, cm-1):3406, 2926, 2857, 1581, 1462, 1087, 758;1H (CDCl3, 400 MHz) : δ 8.64 (d, J = 4.8 Hz, 1H), 8.34-8.32 (m, 1H), 8.02-8.00 (m, 1H), 7.56 (td, J = 7.6, 1.6 Hz, 1H), 7.44-7.41 (m, 2H), 7.35 (d, J = 8.0 Hz, 1H), 7.21-7.18 (m, 1H), 7.06 (d, J = 8.0 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.30 (s, 1H), 4.14 (t, J = 6.4 Hz, 2H), 1.95-1.88 (m, 2H), 1.58-1.54 (m, 2H), 1.41-1.34 (m, 4H), 0.94 (t, J = 5.2 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.3, 147.8, 136.9, 132.3, 129.9, 127.0, 126.7, 126.5, 124.9, 124.3, 122.8, 122.4, 121.5, 103.8, 73.8, 68.3, 31.7, 29.3, 26.1, 22.7, 14.1; HRMS-ESI (m/z): Calculated for C22H24NO2 (M+H): 336.1964, Found (M+H): 336.1960.
 
(1-(heptyloxy)naphthalen-2-yl)(pyridin-2-yl)methanol (CRR-933)

[030] 248 mg, (71% yield) as yellow solid; m.p. 80 oC; IR (KBr, cm-1): 3391, 3068, 2927, 2859, 1585, 1464, 1386, 1086, 760;1H (CDCl3, 400 MHz) : δ 8.64 (dt, J = 4.8, 1.2 Hz, 1H), 8.34-8.32 (m, 1H), 8.03-8.00 (m, 1H), 7.56 (td, J = 7.6, 1.6 Hz, 1H), 7.45-7.40 (m, 2H), 7.36 (d, J = 8.0 Hz, 1H), 7.20-7.17 (m, 1H), 7.06 (d, J = 8.0 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.30 (s, 1H), 4.14 (t, J = 6.4 Hz, 2H), 1.96-1.89 (m, 2H), 1.58-1.52 (m, 2H), 1.43-1.32 (m, 6H), 0.92 (t, J = 6.8 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.3, 147.8, 136.9, 132.3, 129.9, 127.0, 126.7, 126.5, 124.9, 124.3, 122.8, 122.4, 121.5, 103.8, 73.8, 68.3, 31.7, 29.3, 26.1, 22.7, 14.1; HRMS-ESI (m/z): Calculated for C23H27NO2 (M+H):350.2120, Found (M+H): 350.2117.
(1-(octyloxy)naphthalen-2-yl)(pyridin-2-yl)methanol (CRR-934)

[031] 234 mg, (67% yield) as red solid; m.p. 83 ºC; IR (KBr, cm-1): 3386, 3069, 2926, 2858, 1585, 1464, 1385, 1274, 1086, 761;1H (CDCl3, 400 MHz) : δ 8.63-8.62 (m, 1H), 8.35-8.32 (m, 1H), 8.03-8.01 (m, 1H), 7.55 (td, J = 7.6, 1.6 Hz, 1H), 7.46-7.40 (m, 2H), 7.36 (d, J = 8.0 Hz, 1H), 7.20-7.17 (m, 1H), 7.06 (dd, J = 8.0, 0.4 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.31 (s, 1H), 4.12 (t, J = 6.4 Hz, 2H), 1.94-1.90 (m, 2H), 1.58-1.54 (m, 2H), 1.43-1.27 (m, 8H), 0.92 (t, J = 6.8 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.3, 147.9, 136.9, 132.3, 129.9, 127.0, 126.7, 126.6, 124.9, 124.3, 122.8, 122.3, 121.4, 103.8, 73.8, 68.2, 31.9, 29.5, 29.3, 26.4, 22.8, 14.2; HRMS-ESI (m/z): Calculated for C22H24NO2 (M+H): 349.1738, Found (M+H): 349.1726.
 
(1-(decyloxy)naphthalen-2-yl)(pyridin-2-yl)methanol (CRR-935)

[032] 275 mg, (70% yield) as red solid; m.p. 97 ºC; IR (KBr, cm-1): 3397, 2925, 2856, 1584, 1463, 1386, 1271, 1159, 1087, 760; 1H (CDCl3, 400 MHz) : δ 8.63 (d, J = 4.8, Hz, 1H), 8.35-8.33 (m, 1H), 8.03-8.01 (m, 1H), 7.54 (td, J = 8.0, 2.0 Hz, 1H), 7.46-7.42 (m, 2H), 7.36 (d, J = 8.0 Hz, 1H), 7.19-7.16 (m, 1H), 7.07 (dd, J = 8.0, 0.4 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 6.31 (s, 1H), 4.14 (t, J = 6.4 Hz, 2H), 1.96-1.89 (m, 2H), 1.60-1.53 (m, 2H), 1.43-1.29 (m, 10H), 0.92 (t, J = 6.8 Hz, 3H); 13C (CDCl3, 100 MHz): δ 161.5, 155.2, 147.8, 136.8, 132.3, 129.9, 126.9, 126.6, 126.5, 124.9, 124.3, 122.7, 122.3, 121.4, 103.8, 73.8, 68.2, 32.0, 29.73, 29.70, 29.5, 29.4, 29.3, 26.4, 22.8, 14.2; HRMS-ESI (m/z): Calculated for C26H33NO2 (M+H):392.2590, Found (M+H): 392.2586.
(4-methoxyphenyl)(quinolin-2-yl)methanol (CRR-937)

[033] 228mg, (86% Yield) as yellow solid; m.p 69-70 ºC;IR (KBr, cm-1:3436, 2925, 1595, 1506, 1253, 1173, 1043, 814, 744; 1H NMR (400 MHz, CDCl3):δ 8.15-8.13 (m, 1H), 8.06 (d, J = 7.6 Hz, 1H), 7.81-7.73 (m, 2H), 7.57 (m, 1H), 7.32-7.29 (m, 2H), 7.17 (d, J = 8.8 Hz, 1H), 6.87- 6.85 (m, 2H), 5.83 (s, 1H), 3.78 (s, 3H); 13C NMR(100 MHz, CDCl3):δ 160.8, 159.5, 146.0, 137.1, 135.1, 130.0, 128.9, 128.8, 127.7, 127.5, 126.7, 119.4, 114.1, 74.8, 55.3; HRMS-ESI (m/z):Calculated for C17H15NO2 (M+H): 266.1176 Found (M+H): 266.1172.
 
(5-methyl-2-(2-(p-tolyloxy)ethoxy)phenyl)(pyridine-2-yl)methanol (CRR-696)

[034] 258mg, (74%Yield) as colorless semi solid; IR (KBr, cm-1): 3426, 2925, 2860, 1602, 1506, 1241, 1054, 796, 746; 1H NMR (400 MHz, CDCl3) : δ 8.49 (dd, J = 3.6, 1.2 Hz, 1H), 7.54 (td, J = 7.6, 1.6 Hz, 1H), 7.41 (d, J = 8.4 Hz, 1H), 7.18 (d, J = 2.0 Hz, 1H), 7.14-7.08 (m, 3H), 7.03 (dd, J = 8.4, 1.6 Hz, 1H), 6.86- 6.81 (m, 3H), 6.16 (s, 1H), 5.29 (br s, 1H), 4.40-4.26 (m, 4H), 2.29 (s, 3H), 2.26 (s, 3H); 13C NMR(100 MHz, CDCl3) : δ 161.4, 156.5, 153.6, 147.7, 136.8, 132.0, 130.8, 130.5, 130.1, 129.1, 128.6, 122.2, 121.5, 114.5, 112.0, 69.8, 67.2, 66.6, 20.7, 20.6; HRMS-ESI (m/z) : Calculated for C22H23NO3 (M+Na): 372.1576 Found (M+Na): 372.1576.
(5-methyl-2-(3-(p-tolyloxy)propoxy)phenyl)(pyridine-2-yl)methanol (CRR-901)

[035] 251 mg, (69% Yield) as colorless semi solid; IR (KBr, cm-1):3155, 2926, 1599, 1467, 1243, 1050, 998, 813, 742; 1H NMR (400 MHz, CDCl3):δ 8.52-8.50 (m, 1H), 7.44 (td, J = 7.6, 1.6 Hz, 1H), 7.22 (d, 1H), 7.20 (d, J = 0.8 Hz, 1H), 7.16-7.08 (m, 1H), 7.06 (d, J = 8.4 Hz, 2H), 7.02 (dd, J = 8.4, 1.6 Hz, 1H), 6.81 (d, J = 8.4 Hz, 1H), 6.77 (d, J = 8.4 Hz, 2H), 6.13 (s, 1H), 5.30 (br s, 1H), 4.23-4.01 (m, 4H), 2.29 (s, 3H), 2.25 (s, 3H), 2.20 (t, J = 6.4 Hz, 2H); 13C NMR (100 MHz, CDCl3):δ 161.4, 156.8, 153.9, 147.6, 136.8, 131.3, 130.3, 130.0, 130.0, 129.2, 128.7, 122.2, 121.2, 114.4, 111.7, 69.7, 64.9, 64.5, 29.5, 20.7, 20.5; HRMS-ESI (m/z):Calculated for C23H25NO3 (M+H): 364.1913 Found (M+H): 364.1915.
(5-methyl-2-(4-(p-tolyloxy)butoxy)phenyl)(pyridine-2-yl)methanol (CRR-698)

[036] 249 mg, (67% Yield)as colorless semi solid; IR (KBr, cm-1):3176, 2921, 2866, 1600, 1504, 1244, 1045, 806, 750; 1H NMR (400 MHz, CDCl3):δ 8.53 (m, 1H), 7.57 (td, J = 7.6, 1.6 Hz, 1H), 7.29 (dd, J = 8.0, 0.4 Hz, 1H), 7.17-7.08 (m, 2H), 7.07 (d, J = 8.0 Hz, 2H), 7.02 (dd, J = 8.4, 2.0 Hz, 1H), 6.79 (d, J = 8.4 Hz, 3H), 6.14 (s, 1H),5.23 (br s, 1H), 4.11-3.95 (m, 4H),2.28 (s, 3H), 2.25 (s, 3H), 1.93-1.89 (m, 4H); 13C NMR (100 MHz, CDCl3):δ 161.5, 156.9, 154.0, 147.7, 136.8, 131.4, 130.2, 130.0, 129.9, 129.2, 128.7, 122.2, 121.3, 114.4, 111.7, 69.7, 67.9, 67.5, 26.3, 26.1, 20.7, 20.5; HRMS-ESI (m/z):Calculated for C24H27NO3 (M+H): 378.2069 Found (M+H): 378.2071.
(5-methyl-2-(6-(p-tolyloxy)hexyloxy)phenyl)(pyridine-2-yl)methanol (CRR-699)

[037] 261 mg, (64% Yield) as colorless semi solid; IR (KBr, cm-1):3432, 2928, 2860, 1602, 1506, 1242, 1039, 810, 751; 1H NMR (400 MHz, CDCl3):δ 8.54-8.53 (m, 1H), 7.58 (td, J = 7.6, 1.6 Hz, 1H), 7.29 (dd, J = 7.2, 0.8 Hz, 1H), 7.17-7.08 (m, 2H), 7.07 (d, J = 8.4 Hz, 2H), 7.01 (dd, J = 8.4, 1.6 Hz, 1H), 6.80-6.77 (m, 3H), 6.14 (s, 1H), 5.3 ( br s, 1H), 4.04-3.91 (m, 4H), 2.28 (s, 3H), 2.24 (s, 3H), 1.78 (t, J = 7.2 Hz, 4H), 1.49 (t, J = 3.6 Hz, 4H); 13C NMR (100 MHz, CDCl3):δ 161.5, 157.0, 154.1, 147.7, 136.7, 131.4, 130.1, 129.9, 129.8, 129.1, 128.6, 122.2, 121.3, 114.5, 111.7, 69.7, 68.3, 67.9, 29.4, 29.4, 26.0, 26.0, 20.7, 20.5; HRMS-ESI (m/z):Calculated for C26H31NO3 (M+H): 406.2382 Found (M+H): 406.2382.
General procedure for the addition of π-nucleophiles to 3/4-pyridine carboxaldehyde(B):

[038] An oven dried two neck round bottom flask bearing septum in side arm and fitted with condenser was cooled to room temperature under a steady stream of nitrogen gas flow. The flask was charged with stirring bar, AlBr3(1.0 mmol) and dry dichloromethane (3 mL) and cooled down to 0 °C (using ice bath). Then electron deficient aldehydes (1 mmol) in dry dichloromethane (5 mL) at 0 °C with stirring was added followed by the addition of dichloromethane solution of pyridine (0.016 mL, 0.2mmol).
[039] Stirring was continued for 30 minutes. To this mixture was added the dichloromethane (5 mL) solution of nucleophiles (1.0mmol) in drops. The resulting suspension was stirred at room temperature for for 24 h. After cooling to room temperature, the reaction mixture was poured into aq. NaHCO3 and stirred for 5 min. The organic layer was separated and the aqueous layer was extracted with dichloromethane (2 x 15 mL). The combined organic layer was dried over anhydrous Na2SO4, filtered and concentrated on rotary evaporator under reduced pressure. The residue was purified through silica gel column chromatography using ethyl acetate and hexane as an eluent to afford the pure products.
[040] Prior to this study pyridyl aryl carbinols and their derivatives were not evaluated against cancer cell lines. Carbinol possess smaller skeleton and hence easy to modify the structural features. Using our simple methodology, carbinol analogues were synthesized and evaluated for the in vitro anti-cancer activity on the six different cancer cell lines namely lung (A549), breast (MDA MB-231), liver (HepG2), leukemia (K562), colon (HCT-15) and cervical (HeLa) cell lines as well as in normal cell line (PBMCs).
[041] For each derivative under study, different concentrations were tested for 48 h on six different human cancer cell lines as well as in normal cells by MTT assay with taxol as reference (positive control) compound. The carbinol analogues showed differential and dose-dependent suppressive effect on the cancer cells (Figure 1). The dose-response curve revealed that the dose-dependent inhibition in cancer cells such as lung (A549), breast (MDA MB-231), liver (HepG2), leukemia (K562), colon (HCT-15) and cervical (HeLa) cancer cell lines have been observed.
[042] However, a compound substituted with pyridine-3 is less active (CRR-625) compared to pyridine-4 (CRR-688) and pyridine-2 (CRR-687) frameworks. Pyridine-2 derivative (CRR-687) is most potent molecule against all tested cancer cell lines (Table 1). After ascertaining the essential requirement of 2-pyridyl unit for potency against cancer cell lines, we varied the aryl rings with various substituents, heteroaryl group containing carbinols such as thiophene, benzothiophene, indole, pyrrole, furan, benzofuran and substituted heteroaryl (series of pyridyl/heteroaryl) carbinols were synthesized and evaluated for anti-cancer activity (Figure 8).
[043] The results suggesting that the second heteroaryl ring may not be an essential component to show good activity against cancer cell lines (Table 1). Molecules containing 2-pyridyl unit and aryl ring with substituents such as alkyl, halo, nitro, ethers (alkyl or ally or alkenyl ethers), dialkylamino, thioethers which are placed in various positions of phenyl ring as well as combination of above mentioned functional groups in carbinols were evaluated against cancer cell lines (Figure 9). Among all substituents and their combination, only methoxy and methyl group on phenyl ring (CRR-615) showed significant activity against all cancer cell lines (Table 1).
[044] Encouraged by these results and to enhance the activity, the phenyl ring was replaced with naphthyl, anthracenyl, phenanthrenyl and ferrocenyl moieties. Interestingly, the molecule CRR-606 showed best activity against all cancer cell lines (Table 1).
Table 1 Anti-proliferative activity of CRR - analogues in six human cancer cell lines
IC50 value (µM)
Cancer cells Normal cells
Carbinols Lung (A549) Breast
(MDA MB-231) Colon (HCT-15) Liver (HepG2) Cervical
(Hela) Leukemia (K562) PBMC
CRR-604 >100 32.40±6.20 49.94±0.22 11.21±4.2 85.25±2.10 na na
CRR-605 na na na na na na nd
CRR-606 31.21±3.11 15.62±3.20 25.99±0.15 10.87±1.9 22.82±1.50 na na
CRR-607 35.57±3.11 17.40±2.40 51.12±0.25 12.82±6.2 23.83±2.10 na na
CRR-609 na na na na na na 47.96±3
CRR-615 >100 29.08±4.73 41.08±0.16 10.81±6.3 5.46±3.21 na na
CRR-616 >100 38.77±5.21 79.79±5.84 50.87±6.5 na na na
CRR-617 >100 41.76±8.12 32.02±0.68 42.81±3.2 >100 na na
CRR-618 na na na na na na 78.7±4.
CRR-625 34.4±5.7 30.29±8.1 25.55±0.2 Na 42.91±4.2 na na
CRR-630 na na na na na na nd
CRR-631 45.70±3.40 38.90±3.29 32.48±2.52 17.80±2.4 27.80±3.70 na na
CRR-633 na na na na na na 45.65±2
CRR-640 45.31±6.80 10.36±5.15 86.36±0.6 50.81±3.2 39.77±3.10 na na
CRR-641 99.74±5.70 23.86±4.12 20.55±0.1 na 39.66±7.10 na na
CRR-687 na 15.60±0.73 10.90±0.34 21.33±0.16 14.47±0.34 7.500±0.2 na
CRR-688 na 43.60±0.75 15.40±0.12 14.89±0.17 na 42.78±03 na
CRR-902 30.78±1.34 66.85±3.29 37.52±2.34 23.91±0.93 14.98±0.45 44.31±06 na
Taxol 4.509±1.12 2.348±0.28 5.789±0.89 4.363±0.78 3.329±0.67 6.537±0.52 na
IC50 concentrations in µM; na- not active (less than 20 % inhibition); nd- not determined (inhibition between 20 % and 45 %)

Thus, based on the anti-cancer activity studies of these small pool of molecules, we concluded that the presence of 2-pyridyl unit and either 2-methoxy-5-methyl phenyl or 1-methoxy-2-naphthyl as other arene unit are essential structural units to display good activity against cancer cell lines. Based on this preliminary studies two active skeletons have been identified.
Identification of pharmacophores and active skeletons
[045] From these results, we decided to further examine this class of skeletons with structural variation to identify potential lead molecule against cancer ailment because these compounds have not been explored earlier. Hence, carbinol structural core has been segregated into four different pharmacophores such as A, B, C and D (Figure 11).
[046] The present study reveals that the pharmacological property of these molecules mainly depends on the hydrophobic and lipophilic properties of the active molecular framework. These properties may be altered by introducing the substituents on the active molecular framework. Based on the above mentioned results, varying pharmacophore C and D unit with appropriate aryl rings/groups may lead to potential drug molecule.
Table 2. Anti-proliferative activity of CRR - analogues in six human cancer cell lines
Compounds Lung
(A549) Breast
(MDA MB-231) Colon
(HCT-15) Liver
(HepG2) Cervical
(Hela) Leukemia (K562) PBMC
CRR-676 9.458±4.18 14.68±5.36 12.86±3.36 5.821±4.30 4.736±7.10 8.630±2.40 na
CRR-689 1.170±0.12 1.760±0.18 1.023±0.12 1.647±0.17 1.831±0.34 1.471±0.26 na
CRR-690 4.320±0.91 0.476±0.32 0.576±0.70 10.89±0.43 2.724±0.56 2.872±0.54 na
CRR-691 0.820±1.23 0.26±0.530 0.583±0.86 3.946±0.67 0.078±0.18 0.056±0.67 na
CRR-692 0.580±0.23 0.324±0.23 0.723±0.12 0.523±0.13 0.727±0.98 0.928±0.56 na
CRR-693 8.176±0.98 2.556±0.78 2.103±0.81 10.27±0.15 7.178±1.34 2.587±0.58 na
CRR-694 0.003±0.10 0.006±0.18 0.006±0.29 0.005±0.04 0.002±0.06 0.124±0.87 na
CRR-695 8.120±1.89 1.240±0.76 4.242±0.34 3.256±0.93 8.745±0.89 1.324±0.67 na
CRR-696 0.370±0.18 1.667±0.65 0.421±3.15 4.587±0.98 0.312±0.38 7.295±1.79 Na
CRR-697 1.068±1.80 0.022±0.40 1.803±0.45 0.186±0.07 2.473±0.78 0.764±0.14 Na
CRR-698 1.425±0.16 0.124±0.88 1.643±0.21 1.097±1.89 2.444±0.18 0.987±1.76 Na
CRR-699 0.385±0.21 0.654±0.38 0.867±0.17 3.467±0.13 0.456±0.56 0.596±0.15 Na
CRR-901 16.89±0.90 8.980±0.84 8.648±0.28 1.932±0.92 6.817±0.42 4.932±0.92 Na
Taxol 4.509±1.12 2.348±0.28 5.789±0.89 4.363±0.78 3.329±0.67 6.537±0.52 na
IC50 concentrations in µM; na- not active (less than 20 % inhibition); nd- not determined (inhibition between 20 % and 45 %)

 
Table 3. Anti-proliferative activity of CRR - analogues in six human cancer cell lines
Compounds Lung (A549) Breast
(MDA MB-231) Colon
(HCT-15) Liver (HepG2) Cervical (Hela) Leukemia (K562) PBMC
CRR-903 0.008±0.18 0.008±0.16 0.005±0.06 0.004±0.67 0.008±0.34 0.143±0.25 na
CRR-930 0.003±0.25 0.002±0.08 0.003±0.18 0.005±0.15 0.004±0.12 0.004±0.14 na
CRR-931 0.002±0.18 0.002±0.04 0.004±0.09 0.006±0.07 0.004±0.19 0.003±0.12 na
CRR-932 0.002±0.05 0.002±0.09 0.002±0.06 0.005±0.09 0.003±0.12 0.002±0.16 na
CRR-933 0.002±0.12 0.002±0.06 0.004±0.08 0.002±0.08 0.008±0.08 0.008±0.21 na
CRR-934 0.002±0.06 0.002±0.09 0.009±0.09 0.002±0.06 0.006±0.07 0.006±0.61 na
CRR-935 0.001±0.02 0.004±0.12 0.003±0.12 0.003±0.02 0.003±0.13 0.003±0.12 na
Taxol 4.509±1.12 2.348±0.28 5.789±0.89 4.363±0.78 3.329±0.67 6.537±0.52 na
IC50 concentrations in µM; na- not active (less than 20 % inhibition); nd- not determined (inhibition between 20 % and 45 %)

[047] The main advantages of this method are:
 Earlier no such derivatives were evaluated against cancer cell lines.
 Very simple pyridyl aryl carbinols and their derivatives showed very good activities.
 Numerus phormacophoric group changes are possible in these molecules.
 Synthesis of pyridyl aryl/heteroaryl and their derivatives were achieved by simple process.
 The CRR derivatives showed promising cytotoxicity with the induction of apoptosis in cancer cells. Further, CRR derivatives induced oxidative stress that leads to the production of ROS thereby also affecting mitochondrial membrane potential.
Compounds having structures including stereoisomers, pharmaceutically acceptable salts thereof, wherein R, R1, R2, R3, R4, R5, R6 are as defined herein. Such compounds recently identified as in vitro cytotoxic agents against cancer cell lines and thus have utility as cancer therapeutic agents.
, Claims:1. An anticancer compound of Formula (I):

(I)
or a pharmaceutically acceptable salt, stereoisomers and racemates thereof,
wherein
X, Y or Z is independently selected from C or N;
Ar is compound of formula (IIa) or (IIb)

, or
(IIa) (IIb)
wherein
X’, X’’, X’’’, X””, Y’, Y’’, Z’ or Z’’ is independently selected from C, N, O, S;
R1, R2, R3, R4, R5, R6 and R7 is independently selected from the group consisting of (C1-C12)alkyl, (C1-C12)alkoxy, (C1-C18)dioxy, (C1-C12)alkylenedioxy, halo, thio, thio(C1-C12)alkyl, (C6-C16)aryl, (C1-C12)alkyl(C1-C12)alkoxy, (C1-C12)alkyl(C6-C18)aryl, (C1-C12)alkylenedioxy(C6-C18)aryl, (C1-C12)alkyl(C6-C18)heteroaryl, hydroxy(C6-C18)aryl, hydroxy(C6-C18)heteroaryl, (C1-C12)alkoxy(C6-C18)aryl, (C1-C12)alkoxy(C6-C18)heteroaryl, (C1-C12)alkylenedioxy(C6-C18)heteroaryl, (C1-C12)alkylamino(C6-C18)aryl, (C1-C12)alkylamino(C6-C18)heteroaryl,
and their substitute.

2. The compound as claimed in claim 1, wherein the compound is of formula (Ia), (Ib) or (Ic)
, , or
(Ia) (Ib) (Ic)
Wherein
Ar is compound of formula (IIa) or (IIb)

, or
(IIa) (IIb)
wherein
X’, X’’,X’’’, X””, Y’, Y’’, Z’ or Z’’ is C;
R1, R2, R3, R4, R5, R6 and R7 is independently selected from the group consisting of (C1-C12)alkyl, (C1-C12)alkoxy, (C1-C18)dioxy, (C1-C12)alkylenedioxy, halo, thio, thio(C1-C12)alkyl, (C6-C16)aryl, (C1-C12)alkyl(C1-C12)alkoxy, (C1-C12)alkyl(C6-C18)aryl, (C1-C12)alkylenedioxy(C6-C18)aryl, (C1-C12)alkoxy(C6-C18)aryl and their substitute.
3. The compound as claimed in claim 1 selected from:
, , ,
, , , , , , , , , ,
, , , , , ,
, , , , , , , , , , , , , , and .
4. The compound as claimed in claim 1 selected from:
, , , , , , , , , , , , , , , , , , and .
5. The compound as claimed in claim 1 selected from:
, , , , , and .
6. A process for preparing the compound of formula (Ia) comprising steps of:
a) mixing Lewis acid and an organic nonpolar solvent at a low temperature of about 0 °C to provide a solution -1;
b) adding pyridine-2-carboxaldehyde of formula (IIIa) to the solution -1 and stirring at about 0 °C to provide a mixture;
c) reacting the mixture containing pyridine-2-carboxaldehyde with a solution-2 comprising Ar-nucleophile compound

+ArNu

(IIIa) (Ia)
wherein,
Ar is

, or

(IIa) (IIb)
wherein
X’, X’’,X’’’, X””, Y’, Y’’, Z’ or Z’’ is C;
R1, R2, R3, R4, R5, R6 and R7 is independently selected from the group consisting of (C1-C12)alkyl, (C1-C12)alkoxy, (C1-C18)dioxy, (C1-C12)alkylenedioxy, halo, thio, thio(C1-C12)alkyl, (C6-C16)aryl, (C1-C12)alkyl(C1-C12)alkoxy, (C1-C12)alkyl(C6-C18)aryl, (C1-C12)alkylenedioxy(C6-C18)aryl, (C1-C12)alkoxy(C6-C18)aryl and their substitute;
in a nonpolar organic solvent for a period of about 20 hrs to 30 hrs at a room temperature to provide the reaction mixture;
d) suspending the reaction mixture into weak alkali solution, separating organic layer and extracting the aqueous layer with nonpolar organic solvent;
e) combining organic layers, washing with aqueous solution, and concentrating the organic layer to provide crude compound of formula (Ia); and
f) purifying crude compound of formula (Ia) to provide pure compound of formula (Ia).
7. A process for preparing the compound of formula (Ib) or (Ic) comprising steps of:
a) mixing Lewis acid and an organic nonpolar solvent at a low temperature of about 0 °C to provide a solution -1;
b) adding electron deficient carboxaldehyde of formula (IIIb) to the solution -1 and stirring at about 0 °C to provide a mixture;
c) reacting the mixture containing electron deficiencarboxaldehyde with a solution-2 comprising Ar-nucleophile compound

+ArNu

(IIIb) (Ix)
wherein,
Y and Z is independently N;

 
Ar is

, or
(IIa) (IIb)
wherein
X’, X’’,X’’’, X””, Y’, Y’’, Z’ or Z’’ is C;
R1, R2, R3, R4, R5, R6 and R7 is independently selected from the group consisting of (C1-C12)alkyl, (C1-C12)alkoxy, (C1-C18)dioxy, (C1-C12)alkylenedioxy, halo, thio, thio(C1-C12)alkyl, (C6-C16)aryl, (C1-C12)alkyl(C1-C12)alkoxy, (C1-C12)alkyl(C6-C18)aryl, (C1-C12)alkylenedioxy(C6-C18)aryl, (C1-C12)alkoxy(C6-C18)aryl and their substitute;
in a nonpolar organic solvent for a period of about 20 hrs to 30 hrs at a room temperature to provide the reaction mixture;
d) suspending the reaction mixture into weak alkali solution, separating organic layer and extracting the aqueous layer with nonpolar organic solvent;
e) combining organic layers, washing with aqueous solution, and concentrating the organic layer to provide crude compound of formula (Ix); and
f) purifying crude compound of formula (Ix) to provide pure compound of formula (Ix).
8. The process as claimed in any one of claims 6 or 7, wherein the Lewis acid is selected from AlBr3 or FeBr3.
9. The process as claimed in any one of claims 6 or 7, wherein the nonpolar organic solvent is selected from CHCl2 or CHCl3, diethyl ether, pentane, hexane, benzene, or the like.
10. The process as claimed in any one of claims 6 or 7, wherein the weak alkali solution is selected from solution of sodium bicarbonate, potassium bicarbonate, Calcium hydroxide, Ammonium hydroxide or the like.
11. The process as claimed in any one of claims 6 or 7, wherein the aqueous solution is aqueous solution of sodium chloride.
12. The process as claimed in claim 7, wherein the compound of formula (Ix)

(Ix) is compound of formula (Ib) or (Ic):

, or
(Ib) (Ic)

wherein
X’, X’’,X’’’, X””, Y’, Y’’, Z’ or Z’’ is C;
R1, R2, R3, R4, R5, R6 and R7 is independently selected from the group consisting of (C1-C12)alkyl, (C1-C12)alkoxy, (C1-C18)dioxy, (C1-C12)alkylenedioxy, halo, thio, thio(C1-C12)alkyl, (C6-C16)aryl, (C1-C12)alkyl(C1-C12)alkoxy, (C1-C12)alkyl(C6-C18)aryl, (C1-C12)alkylenedioxy(C6-C18)aryl, (C1-C12)alkoxy(C6-C18)aryl and their substitute.