Description:FIELD OF THE INVENTION
The present invention relates to the field of nanotechnology and green chemistry. More particularly, it pertains to the ecofriendly synthesis of zinc oxide (ZnO) nanoparticles using plant-based materials. Specifically, the invention involves the use of Phaleria macrocarpa (God’s Crown) fruit extract for the green synthesis of ZnO nanoparticles and their application in antibacterial treatments.
BACKGROUND OF THE INVENTION
References which are cited in the present disclosure are not necessarily prior art and therefore their citation does not constitute an admission that such references are prior art in any jurisdiction. All publications, patents and patent applications herein are incorporated by reference to the same extent as if each individual or patent application was specifically and individually indicated to be incorporated by reference.
The present invention relates to the field of nanotechnology, specifically to the synthesis and application of zinc oxide nanoparticles using Phaleria macrocarpa plant extract which are paving the way for exciting advancements in nanotechnology. These tiny particles pack a punch with their strong antibacterial properties and environmentally friendly production methods. The synthesis of these nanoparticles is noteworthy for its use of Phaleria macrocarpa extract, which acts as a natural reducing and stabilizing agent. This means that the nanoparticles are formed without the need for harmful chemicals, making the process much kinder to the environment. The synthesized ZnO nanoparticles find applications in medical devices, food packaging, water purification and further steps to contribute towards sustainable goals.
This pioneering study reports the first-ever synthesis of zinc oxide nanoparticles (ZnO NPs) using Phaleria macrocarpa plant extract, along with comprehensive characterization and analysis. The pharmacological richness of Phaleria macrocarpa was harnessed to investigate its potential as a novel, bio-inspired reducing agent in ZnO NP synthesis. This research demonstrates the feasibility of utilizing Phaleria macrocarpa extract as a sustainable and eco-friendly precursor for ZnO NP production, opening up new avenues for biomedical, environmental, and technological applications in field of nanotechnology.
Nanotechnology has introduced transformative advancements in food science, addressing critical aspects of food processing, packaging, safety, and nutrition. Nanomaterials, encompassing nanoparticles, nanocomposites, and nano-emulsions, demonstrate potential in enhancing food quality, shelf life, and safety, thereby addressing pressing concerns in the food industry. In this research zinc acetate was used as a metal precursor to prepare ZnO NPs using Phaleria macrocarpa plant extract. Zinc acetate plays a crucial role in various applications due to its versatile properties. Its importance lies in addressing zinc deficiencies, which can impact immune function, growth, and development. This compound is notable for being a key precursor in the synthesis of zinc oxide nanoparticles, known for their impressive antibacterial properties. Mahkota Dewa (phaleria macrocarpa), or God’s crown, is a plant originating from Papua Island, Indonesia and is currently being cultivated in Kerala. It has a wide variety of health benefits such as its antioxidant, anti-inflammatory and anti-cancer properties. It also confirms the presence of various important bioactive compounds such as phenolic compounds, alkaloids, benzophenones, etc. due to these properties it is important is treating diabetes, cancer, heart and liver problems, skin problems and detoxification of liver and digestive system, impotence, allergies, rheumatism, high blood pressure, migraine, and hemorrhoids. Zinc Oxide nanoparticles that were prepared using Zinc Acetate as a base from the dried fruit slices of Phaleria macrocarpa also known as God’s Crown were converted to powdered form. The plant extract helps convert zinc acetate into ZnO NPs, which then interact with bacterial cell membranes, causing the cells to break down and die. This green synthesis method not only produces effective antibacterial agents but also supports sustainable development goals.
Several patents issued for nanoparticles but none of these are related to the present invention. Patent US20110110723A1 relates to methods of making and using and compositions of metal nanoparticles formed by green chemistry synthetic techniques. For example, the present invention relates to metal nanoparticles formed with solutions of fruit extracts and use of these metal nanoparticles in removing contaminants from soil and groundwater and other contaminated sites. A method for making one or more metal nanoparticles, comprising: providing a metal ion; providing a fruit extract that comprises a compound selected from the group consisting of a reducing agent, a capping agent, a stabilizing agent, a solvent, a vitamin, a sugar, a peptide, a polyphenol, an alcohol, an anthocyanin, and combinations; and combining the metal ion and the fruit extract to produce metal nanoparticles, wherein if the fruit extract is from a citrus fruit, the fruit extract comprises a compound selected from the group consisting of a reducing agent, a capping agent, a peptide, a polyphenol, an alcohol, an anthocyanin, and combinations.
Another patent US20100200501A1 relates to methods of making and using and compositions of metal nanoparticles formed by green chemistry synthetic techniques. For example, the present invention relates to metal nanoparticles formed with solutions of plant extracts and use of these metal nanoparticles in removing contaminants from soil and groundwater and other contaminated sites. In some embodiments, the invention comprises methods of making and using compositions of metal nanoparticles formed using green chemistry techniques.
Another patent CN102065879B provides a pharmaceutical dosage form consisting of an extract of Phaleria macrocarpa which has antineoplastic, anti-inflammatory and antiangiogenic activity. Its use as an antineoplastic agent is to inhibit tumour growth. Its use as an anti-inflammatory agent is to relieve inflammation and pain, and also as an antipyretic. Another use is as an antiangiogenic agent to inhibit the growth of new blood vessels to prevent cancer metastasis.
Another patent US20230105226A1 relates to a broad-spectrum biocidal composition, with fungicidal and bactericidal activity, containing metal or metal oxide nanoparticles, polymeric thickeners, plant extracts, surfactants, and additives in an aqueous solvent, as well as the method for in situ production of said metal nanoparticles under controlled operating conditions: concentration, volumetric ratio, time, agitation, temperature, and pH, using plant extracts as reducing agents. A biocidal composition comprising: metal or metal oxide nanoparticles; a vegetable extract; wherein the metal of the nanoparticles is selected from the group of transition metals, XIII and XIV; and wherein the plant extract is selected from an extract of Passiflora ligularis, Sambucus mexicana, Selenicereus megalanthus, Solanum quitoense, Annona cherimola, Solanum bataceum, Cucurbita moschata, Luffa aegyptiaca, Arracacia xanthorrhiza, Fragaria ananassa, Furcraea andina, Alibertia patinoi, Pourteria sapota, Ficus carica, Passiflora quadrangularis, Vaccinium meridionale, Passiflora maliformis, Bactris gasipaes, Cassia grandis, Vasconcellea pubescens, Melicoccus bijugatus, and Mammea americana.
Another patent US9392795B2 relates to a photocatalytic composition comprising zinc (Zn) doped titanium dioxide (TiO2) nanoparticles, wherein the ratio of titanium dioxide nanoparticles to zinc is from about 5 to about 150. The photocatalytic composition absorbs electromagnetic radiation in a wavelength range from about 200 nm to about 500 nm, and the absorbance of light of wavelengths longer than about 450 nm is less than 50% the absorbance of light of wavelengths shorter than about 350 nm.
OBJECTS OF THE INVENTION
Main object of the present invention is to Ecofriendly synthesis of zinc oxide nanoparticles using Phaleria macrocarpa (God’s Crown) fruit and its antibacterial activity.
Another object of the present invention is to provide an ecofriendly and sustainable method for synthesizing zinc oxide (ZnO) nanoparticles using Phaleria macrocarpa (God’s Crown) fruit extract.
Another object of the present invention is to utilize the phytochemical constituents present in Phaleria macrocarpa fruit as natural reducing and stabilizing agents in the green synthesis of ZnO nanoparticles.
Another object of the present invention is to eliminate the use of hazardous chemicals and energy-intensive processes typically involved in conventional nanoparticle synthesis.
Another object of the present invention is to characterize the biosynthesized ZnO nanoparticles using techniques such as UV-Vis spectroscopy, FTIR, XRD, and SEM.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention.
This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings.
The present invention provides an ecofriendly and cost-effective method for synthesizing zinc oxide (ZnO) nanoparticles using the fruit extract of Phaleria macrocarpa (commonly known as God’s Crown). The invention utilizes the bioactive phytochemicals naturally present in the fruit extract as both reducing and stabilizing agents, thereby eliminating the need for toxic chemicals or external stabilizers commonly used in conventional synthesis methods. The green synthesis process results in stable ZnO nanoparticles, which are further characterized using analytical techniques such as UV-Vis spectroscopy, FTIR, XRD, and SEM to confirm their nano-scale size and crystalline structure. The biosynthesized ZnO nanoparticles exhibit significant antibacterial activity against both Gram-positive and Gram-negative bacterial strains, making them suitable for applications in antimicrobial coatings, wound dressings, and water purification systems. This invention offers a sustainable, safe, and efficient alternative to traditional nanoparticle synthesis approaches, promoting environmental and human health benefits.
Herein enclosed an ecofriendly method for the synthesis of zinc oxide nanoparticles, the method comprising:
preparing an aqueous extract of Phaleria macrocarpa fruit by drying, grinding, and heating with distilled water;
filtering the extract to obtain a clear plant extract;
adding zinc acetate solution to the filtered extract;
adjusting the pH to 12 using sodium hydroxide (NaOH);
stirring the reaction mixture at a temperature between 60°C and 70°C for a duration of 2 hours;
centrifuging the resultant mixture at 4000 rpm; and
drying the obtained precipitate to yield zinc oxide nanoparticles.
5 grams of Phaleria macrocarpa fruit powder is mixed with 250?mL of distilled water for extract preparation.
The zinc oxide nanoparticles are formed without the use of any external chemical reducing or stabilizing agents.
The synthesized zinc oxide nanoparticles exhibit antibacterial activity against Gram-positive and Gram-negative bacteria.
The zinc oxide nanoparticles exhibit a characteristic absorption peak at 360 nm in the UV-Visible spectrum, confirming their nanoscale size.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated embodiments of the subject matter will be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
Fig 1: Phaleria macrocarpa, Dried grounded Fruit powder, Synthesized ZnO NPs
Fig 2: Visual observation of plant extract and their synthesized NPs; A) Plant extract (B) Zinc acetate dihydrate solution (C) Final color
Fig 3: UV-visible spectroscopic analysis of synthesized ZnO NPs
Fig 4: XRD pattern of synthesized ZnO NPs
Fig 5. SEM analysis of synthesized ZnO nanoparticles
Fig 6: Antimicrobial activity of synthesized ZnO NPs
DETAILED DESCRIPTION OF THE INVENTION
The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
In addition, the descriptions of "first", "second", “third”, and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In some embodiments of the present invention, the present invention describes an ecofriendly and efficient method for synthesizing zinc oxide (ZnO) nanoparticles using the aqueous fruit extract of Phaleria macrocarpa (God’s Crown).
In some embodiments of the present invention, the process begins with the preparation of the plant extract, wherein mature fruits are washed, sliced, and shade-dried to preserve their bioactive compounds. The dried fruit slices are then ground into a fine powder, and 5 grams of this powder are mixed with 250?mL of distilled water.
In some embodiments of the present invention, the mixture is heated to extract the phytochemicals responsible for reducing and stabilizing metal ions. After sufficient heating, the extract is filtered to remove solid residues.
In some embodiments of the present invention, this filtrate, rich in natural antioxidants, flavonoids, and other secondary metabolites, serves as a green reagent for nanoparticle synthesis, replacing hazardous chemicals typically used in conventional methods.
In some embodiments of the present invention, to synthesize the ZnO nanoparticles, zinc acetate is added to the prepared plant extract. The pH of the reaction mixture is adjusted to 12 by the dropwise addition of sodium hydroxide (NaOH), which facilitates the precipitation of zinc hydroxide.
In some embodiments of the present invention, this mixture is then stirred continuously at a temperature range of 60–70?°C for 2 hours, during which ZnO nanoparticles are formed via nucleation and growth.
In some embodiments of the present invention, after the reaction completes, the suspension is centrifuged at 4000?rpm to separate the ZnO nanoparticles. The precipitate is thoroughly washed with distilled water and ethanol to remove unreacted substances and then dried to obtain pure ZnO nanopowder.
In some embodiments of the present invention, UV-Vis spectroscopy confirmed the formation of nanoparticles with a prominent absorption peak at 360?nm, indicative of small particle size. This green synthesis approach offers a sustainable, low-cost, and scalable alternative to chemical routes while also imparting excellent antibacterial properties to the resulting nanoparticles.
Herein enclosed an ecofriendly method for the synthesis of zinc oxide nanoparticles, the method comprising:
preparing an aqueous extract of Phaleria macrocarpa fruit by drying, grinding, and heating with distilled water;
filtering the extract to obtain a clear plant extract;
adding zinc acetate solution to the filtered extract;
adjusting the pH to 12 using sodium hydroxide (NaOH);
stirring the reaction mixture at a temperature between 60°C and 70°C for a duration of 2 hours;
centrifuging the resultant mixture at 4000 rpm; and
drying the obtained precipitate to yield zinc oxide nanoparticles.
5 grams of Phaleria macrocarpa fruit powder is mixed with 250?mL of distilled water for extract preparation.
The zinc oxide nanoparticles are formed without the use of any external chemical reducing or stabilizing agents.
The synthesized zinc oxide nanoparticles exhibit antibacterial activity against Gram-positive and Gram-negative bacteria.
The zinc oxide nanoparticles exhibit a characteristic absorption peak at 360 nm in the UV-Visible spectrum, confirming their nanoscale size.
EXAMPLE 1
BEST METHOD
Preparation of ZnO NPs
The present invention describes an ecofriendly and efficient method for synthesizing zinc oxide (ZnO) nanoparticles using the aqueous fruit extract of Phaleria macrocarpa (God’s Crown). The process begins with the preparation of the plant extract, wherein mature fruits are washed, sliced, and shade-dried to preserve their bioactive compounds. The dried fruit slices are then ground into a fine powder, and 5 grams of this powder are mixed with 250?mL of distilled water. The mixture is heated to extract the phytochemicals responsible for reducing and stabilizing metal ions. After sufficient heating, the extract is filtered to remove solid residues. This filtrate, rich in natural antioxidants, flavonoids, and other secondary metabolites, serves as a green reagent for nanoparticle synthesis, replacing hazardous chemicals typically used in conventional methods.
To synthesize the ZnO nanoparticles, zinc acetate is added to the prepared plant extract. The pH of the reaction mixture is adjusted to 12 by the dropwise addition of sodium hydroxide (NaOH), which facilitates the precipitation of zinc hydroxide. This mixture is then stirred continuously at a temperature range of 60–70?°C for 2 hours, during which ZnO nanoparticles are formed via nucleation and growth. After the reaction completes, the suspension is centrifuged at 4000?rpm to separate the ZnO nanoparticles. The precipitate is thoroughly washed with distilled water and ethanol to remove unreacted substances and then dried to obtain pure ZnO nanopowder. UV-Vis spectroscopy confirmed the formation of nanoparticles with a prominent absorption peak at 360?nm, indicative of small particle size. This green synthesis approach offers a sustainable, low-cost, and scalable alternative to chemical routes while also imparting excellent antibacterial properties to the resulting nanoparticles.
Preparation of Plant Extract
Drying of fruit slices
?
Grinding dried fruit into fine powder
?
Adding 250 ml water in 5g sample
?
Heating
?
Filtration of plant extract
Adding of Metal precursor
Addition of Zinc Acetate in filtered plant extract
?
Adding of NaOH to maintain pH at 12
?
Mixture Sample
Stirring
(temp - 60 to 70 °C for 2hrs)
Centrifugation
(at 4000 rpm)
Drying
EXAMPLE 2
EXPERIMENTAL DATA
UV- Spectroscopy:
Phaleria macrocarpa fruit extract showed maximum absorption spectrum bands at 360 nm and minimum absorption spectrum at 380 nm. Larger nanoparticles show a higher absorbance wavelength, whereas smaller nanoparticles exhibit a lower wavelength.
XRD Analysis:
The XRD was recorded in the range of 2? = 20 - 80 °. The obtained 2? angles values at (100) 32.09°, (002) 34.7°, (101) 36.58°, (102) 47.88°, (110) 56.86°, (103) 63.14°, (200) 66.69°, (112) 68.23°, (201) 69.35°, (004) 72.84°, (202) 77.23°. XRD analysis of ZnO nanoparticles reported crystallinity and purity of the material.
SEM Analysis:
According to the analysis the synthesized nanoparticles appear to be spherical leading to clumping-like formation of nanoscale.
Antimicrobial Property

This study focuses on the eco-friendly creation of zinc oxide nanoparticles using extracts from dried slices of Phaleria macrocarpa fruit. These findings suggest that zinc oxide nanoparticles from Phaleria macrocarpa have potential for further research and product development. Overall, Phaleria macrocarpa integration into nanotechnology—presents promising avenues to advance medical and environmental applications, though careful handling and further research are deemed indispensable to maximize the benefits and reduce risks.
ADVANTAGE OF THE PRESENT INVENTION
The nanoparticle synthesis occurs through an eco-friendly process, eliminating the requirement for toxic chemicals and thereby minimizing environmental impact.
These versatile ZnO NPs can be used in a variety of ways, including medical treatments, food preservation, and water purification.
They can be applied as antimicrobial coatings on medical devices or used in packaging materials that keep food fresh for longer periods.
They offer a sustainable and biocompatible solution for fighting bacterial infections, a pressing issue as antibiotic resistance continues to rise.
Zinc acetate has diverse applications in dietary supplements, medicine, and industries
Phaleria macrocarpa extract has been successfully employed to synthesize ZnO NPs, exhibiting outstanding antibacterial properties.

, Claims:1. An ecofriendly method for the synthesis of zinc oxide nanoparticles comprising the steps of:
• preparing an aqueous extract of Phaleria macrocarpa fruit by drying, grinding, and heating with distilled water;
• filtering the extract to obtain a clear plant extract;
• adding zinc acetate solution to the filtered extract;
• adjusting the pH to 12 using sodium hydroxide (NaOH);
• stirring the reaction mixture at a temperature between 60°C and 70°C for a duration of 2 hours;
• centrifuging the resultant mixture at 4000 rpm; and
• drying the obtained precipitate to yield zinc oxide nanoparticles.
2. The method as claimed in claim 1, wherein 5 grams of Phaleria macrocarpa fruit powder is mixed with 250?mL of distilled water for extract preparation.
3. The method as claimed in claim 1, wherein the zinc oxide nanoparticles are formed without the use of any external chemical reducing or stabilizing agents.
4. The method as claimed in claim 1, wherein the synthesized zinc oxide nanoparticles exhibit antibacterial activity against Gram-positive and Gram-negative bacteria.
5. The method as claimed in claim 1, wherein the zinc oxide nanoparticles exhibit a characteristic absorption peak at 360 nm in the UV-Visible spectrum, confirming their nanoscale size.