Product development and characterization of the Ayurvedic herbo-mineral-metallic compound- Hridayarnava Rasa

BACKGROUND

Herbo-mineral-metallic formulations are an inseparable part of the Ayurveda system of traditional medicine. Hridayarnava Rasa (HR) is a preparation containing metals like copper, sulphur, and mercury in processed forms and other herbs that do not produce toxic effects and adverse drug reactions when taken in appropriate dosage. Ayurveda practitioners use it in treating cardiac diseases like hypertension, cardiotoxicity and many more. The rasa-aushadhis possess characteristics such as rapid efficacy, little dosage required, and extensive therapeutic applicability. Hridayarnava Rasa [AFI Part-1, 20:55] has been employed for the treatment of various diseases from ancient times. A systematic study of these formulations manufacturing is required to maintain their quality, safety, and efficacy is a need of time to protect the immense faith of patients in Ayurveda.

OBJECTIVES

The present study aimed to prepare HR as per standard operating procedures mentioned in the classical text and to characterize it physio-chemically using advanced analytical techniques.

MATERIALS AND METHODS

HR was prepared and physicochemical analyses and assay of elements by ICP-AES were carried out as per Ayurvedic Pharmacopoeia of India (API). Powder X-ray diffraction (XRD), Field emission gun scanning electron microscopy with energy dispersive spectroscopy (FEG SEM, EDAX), CHNS-O analysis, Fourier Transform Infrared Spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), Particle size distribution analysis (PSD) was carried out.

RESULTS

The XRD analysis of HR showed the presence of unreacted sulphur and sulfides of copper and mercury. FEG SEM revealed the particles in the form of aggregates as nanocrystallites in the range of 100-1000 nm. Elemental analysis showed the presence of copper, sulphur, and mercury in major, along with traces of iron, calcium, sodium, potassium, and magnesium. In FTIR analysis, 18 peaks were observed, which strongly suggests the presence of various organic groups. In the TGA, four peaks were seen, which can be attributed to sulphur volatilization and oxidative changes in mercury. In PSD analysis, 50% of the material was found below 16.40 μm.

CONCLUSION

To establish a piece of fundamental knowledge and ensure uniformity of these rasa-aushadhis, it is imperative to conduct an analysis of their characteristics as per classical texts and modern analytical techniques. Additionally, it is crucial to investigate the significance of each procedural step included in the preparation process. The inferences drawn are helpful as an essential aid for quality assurance and standardization of this herbo-mineral-metallic formulation.

Eco-friendly and sustainable basil seed hydrogel-loaded copper hydroxide-based catalyst for the synthesis of propargylamines and tetrazoles

The broad use of propargyl amines and tetrazoles in pharmaceutical applications presents a well-established challenge. Their synthesis relies heavily on catalysis, which, in turn, has been hindered by the scarcity of stable and practical catalysts. In response to this issue, we have developed an environmentally friendly and sustainable catalyst by infusing copper hydroxide into basil seed hydrogel (Cu(OH)2-BSH), creating a 3D nanoreactor support structure. To verify the structural, physical, chemical, and morphological properties of the prepared samples, a comprehensive analysis using various techniques, including FT-IR, EDX, FE-SEM, TEM, XRD, BET, TGA, and XPS, were conducted. The results not only confirmed the presence of Cu(OH)2 but also revealed a porous structure, facilitating faster diffusion and providing a substantial number of active sites. This catalyst boasts a high surface area and can be easily recovered, making it a cost-effective, safe, and readily available option. This catalyst was applied to the synthesis of propargyl amines and tetrazoles through multi-component reactions (MCRs), achieving excellent results under mild conditions and in a remarkably short timeframe. Consequently, this work offers a straightforward and practical approach for designing and synthesizing metal hydroxides and 3D hydrogels for use in heterogeneous catalysis during organic syntheses. This can be achieved using basic and affordable starting materials at the molecular level.

Freestanding 3D Metallic Micromesh for High-Performance Flexible Transparent Solid-State Zinc Batteries

Flexible transparent energy supplies are extremely essential to the fast-growing flexible electronic systems. However, the general developed flexible transparent energy storage devices are severely limited by the challenges of low energy density, safety issues, and/or poor compatibility. In this work, a freestanding 3D hierarchical metallic micromesh with remarkble optoelectronic properties (T = 89.59% and R_s = 0.23 Ω sq^-1 ) and super-flexibility is designed and manufactured for flexible transparent alkaline zinc batteries. The 3D Ni micromesh supported Cu(OH)₂ @NiCo bimetallic hydroxide flexible transparent electrode (3D NM@Cu(OH)₂ @NiCo BH) is obtained by a combination of photolithography, chemical etching, and electrodeposition. The negative electrode is constructed by electrodeposition of electrochemically active zinc on the surface of Ni@Cu micromesh (Ni@Cu@Zn MM). The metallic micromesh with 3D hierarchical nanoarchitecture can not only ensure low sheet resistance, but also realize high mass loading of active materials and short electron/ion transmission path, which can guarantee high energy density and high-rate capability of the transparent devices. The flexible transparent 3D NM@Cu(OH)₂ @NiCo BH electrode realizes a specific capacity of 66.03 μAh cm^-2 at 1 mA cm^-2 with a transmittance of 63%. Furthermore, the assembled solid-state NiCo-Zn alkaline battery exhibits a desirable energy density/power density of 35.89 μWh cm^-2 /2000.26 μW cm^-2 with a transmittance of 54.34%.

A sustainable pseudo-homogeneous catalyst from renewable biomass: design, development and catalytic applications

Pseudo-homogeneity, sustainability and functional growth in a sustainable raw material derived catalyst.

Sustainable Removal of Contaminants by Biopolymers: A Novel Approach for Wastewater Treatment. Current State and Future Perspectives

Naturally occurring substances or polymeric biomolecules synthesized by living organisms during their entire life cycle are commonly defined as biopolymers. Different classifications of biopolymers have been proposed, focusing on their monomeric units, thus allowing them to be distinguished into three different classes with a huge diversity of secondary structures. Due to their ability to be easily manipulated and modified, their versatility, and their sustainability, biopolymers have been proposed in different fields of interest, starting from food, pharmaceutical, and biomedical industries, (i.e., as excipients, gelling agents, stabilizers, or thickeners). Furthermore, due to their sustainable and renewable features, their biodegradability, and their non-toxicity, biopolymers have also been proposed in wastewater treatment, in combination with different reinforcing materials (natural fibers, inorganic micro- or nano-sized fillers, antioxidants, and pigments) toward the development of novel composites with improved properties. On the other hand, the improper or illegal emission of untreated industrial, agricultural, and household wastewater containing a variety of organic and inorganic pollutants represents a great risk to aquatic systems, with a negative impact due to their high toxicity. Among the remediation techniques, adsorption is widely used and documented for its efficiency, intrinsic simplicity, and low cost. Biopolymers represent promising and challenging adsorbents for aquatic environments’ decontamination from organic and inorganic pollutants, allowing for protection of the environment and living organisms. This review summarizes the results obtained in recent years from the sustainable removal of contaminants by biopolymers, trying to identify open questions and future perspectives to overcome the present gaps and limitations.

Polymer Beads Decorated with Dendritic Systems as Supports for A3 Coupling Catalysts

Abstract

The gel type microscopic polymer beads bearing epoxy functionalities were modified using the two-stage procedures in order to decorate their surface with the moieties of the zeroth order PAMAM type dendrimer and different heterocyclic aldehydes (2-pyridinecarboxaldehyde, 2-pyrrolidinecarboxaldehyde, furfural or 2-thiophenecarboxaldehyde). The polymeric supports provided in this manner were then used for the immobilization of copper(II) ions. The resulting materials were characterized using different instrumental techniques (optical microscopy, SEM, FTIR microscopy, DR UV–Vis, ICP-OES, and thermal analysis). They were also used as catalysts in the model A3 coupling reaction of benzaldehyde, morpholine and phenylacetylene. The best catalytic activity was found for the polymeric catalyst bearing 2-pyridinecarboxaldehyde moieties. It turned out to be effective in the A3 coupling reactions included different benzaldehyde, alkyne, and secondary amine derivatives, as well. It could also be recycled several times without a significant decrease in its activity in the model A3 coupling reaction.

Graphic Abstract

Starch, cellulose, pectin, gum, alginate, chitin and chitosan derived (nano)materials for sustainable water treatment: A review

Natural biopolymers, polymeric organic molecules produced by living organisms and/or renewable resources, are considered greener, sustainable, and eco-friendly materials. Natural polysaccharides comprising cellulose, chitin/chitosan, starch, gum, alginate, and pectin are sustainable materials owing to their outstanding structural features, abundant availability, and nontoxicity, ease of modification, biocompatibility, and promissing potentials. Plentiful polysaccharides have been utilized for making assorted (nano)catalysts in recent years; fabrication of polysaccharides-supported metal/metal oxide (nano)materials is one of the effective strategies in nanotechnology. Water is one of the world's foremost environmental stress concerns. Nanomaterial-adorned polysaccharides-based entities have functioned as novel and more efficient (nano)catalysts or sorbents in eliminating an array of aqueous pollutants and contaminants, including ionic metals and organic/inorganic pollutants from wastewater. This review encompasses recent advancements, trends and challenges for natural biopolymers assembled from renewable resources for exploitation in the production of starch, cellulose, pectin, gum, alginate, chitin and chitosan-derived (nano)materials.

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

Heterocycles have been found to be of much importance as several nitrogen- and oxygen-containing heterocycle compounds exist amongst the various USFDA-approved drugs. Because of the advancement of nanotechnology, nanocatalysis has found abundant applications in the synthesis of heterocyclic compounds. Numerous nanoparticles (NPs) have been utilized for several organic transformations, which led us to make dedicated efforts for the complete coverage of applications of metal nanoparticles (MNPs) in the synthesis of heterocyclic scaffolds reported from 2010 to 2019. Our emphasize during the coverage of catalyzed reactions of the various MNPs such as Ag, Au, Co, Cu, Fe, Ni, Pd, Pt, Rh, Ru, Si, Ti, and Zn has not only been on nanoparticles catalyzed synthetic transformations for the synthesis of heterocyclic scaffolds, but also provide an inherent framework for the reader to select a suitable catalytic system of interest for the synthesis of desired heterocyclic scaffold.

In Situ Immobilized Silver Nanoparticles on Rubia tinctorum Extract-Coated Ultrasmall Iron Oxide Nanoparticles: An Efficient Nanocatalyst with Magnetic Recyclability for Synthesis of Propargylamines by A3 Coupling Reaction

This research suggests a green method for synthesizing hybrid magnetic nanocomposites that can be used as a reductant and a stabilizing agent for immobilizing metal nanoparticles (NPs). The central idea is the modification of magnetic NPs using Rubia tinctorum extract, which consists of numerous carbonyl and phenolic hydroxyl functional groups to increase adsorption of metals and chelate silver ions, and decrease the adsorption of silver ions by Ag NPs, in situ. Thus, the suggested catalyst preparation process does not require toxic reagents, additional reductants, and intricate instruments. To show the effectiveness of the plant extract in reducing and immobilizing Ag NPs, the structural, morphological, and physicochemical features of the particles are studied using Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, vibrating sample magnetometry, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. One of the advantages of the suggested method is to reduce the size of the magnetic NPs from 15-20 to 2-5 nm, in the presence of the extract. Additionally, the prepared Fe3O4@R. tinctorum/Ag nanocatalyst is demonstrated to exhibit a very high activity in the catalysis of the three-component reaction of aldehydes, amines, and alkynes (A3 coupling) with good to high yields of diverse propargylamines. Moreover, the nanocatalyst can be recovered several times with no considerable leaching or loss of performance.

Polysaccharide-based superporous hydrogel embedded with copper nanoparticles: a green and versatile catalyst for the synthesis of 1,2,3-triazoles

This study demonstrates that a polysaccharide-based hydrogel embedded with copper nanoparticles catalyzes cycloaddition reactions involving different azide and alkyne precursors.

Bimetallic Fe-Cu Nanocomposites on Sand Particles for the Inactivation of Clinical Isolates and Point-of-Use Water Filtration

Bimetallic Fe-Cu nanocomposites with an average size of 26.4 ± 4.7 nm were prepared on the surface of fine sand particles by modified coprecipitation and the chemical reduction method and were applied as an in vitro broad spectrum antimicrobial agent and recyclable hand-held water filter to sieve bacteria and metals. The size of the nanocomposites could be further reduced to 11.8 ± 1.6 nm when prepared after ball milling the sand particles, keeping the antimicrobial property intact. The results showed that the chemical nature and morphology of the nanocomposites had a great effect on both Gram-positive and Gram-negative bacteria with a minimum inhibitory concentration of 10.6 μg/mL and 13.8 μg/mL of copper, whereas the minimum bactericidal concentration was found to be 15.9 μg/mL and 21.2 μg/mL. The nanocomposites exhibited antimicrobial activity against multidrug-resistant bacteria as well as fungus isolated from different human biological samples like blood, urine, pus, and wound swabs. The nanocomposites were also capable of filtering a wide range bacteria like Acinetobacter baumannii, Escherichia coli, Salmonella typhi, Bacteroides fragilis, Salmonella paratyphi, Shigella dysenteriae, and Enterococcus faecalis, which are predominantly responsible for waterborne diseases. Further, the nanocomposites were used for the removal of hazardous metals like nickel, zinc, and lead. Leaching of copper and iron from the nanocomposites was within the permissible limit as per Bureau of Indian Standards (BIS) for Drinking Water (IS-10500-2012, second revision) as well as the International Standards for Drinking Water.

Green synthesis of Au nanoparticles using an aqueous extract of Stachys lavandulifolia and their catalytic performance for alkyne/aldehyde/amine A3 coupling reactions

High reaction rate and easy availability make green synthesis of metal nanoparticles noticeable. In the present study, gold nanoparticles with wide applications in different fields were synthesized by an ecofriendly method at room temperature using Stachys lavandulifolia extract as the reducing agent. Properties of the synthesized gold nanoparticles (GNP) were identified by different analytical techniques including: UV-Vis absorption spectroscopy verified presence of Au NPs in the solution while functional groups of its extract and synthesized Au NPs were determined by FT-IR. Its crystalline analysis with a fcc plane was verified by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) determined elements in the sample. Surface morphology, diverse shapes and sizes of the Au NPs were shown by scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Beginning and end destruction temperatures of the Au/S. lavandulifolia NPs were determined by thermal gravimetric analysis (TGA). The Au nanoparticles were capped with extracts, preventing them from oxidation and agglomeration and were used as an efficient heterogeneous nanocatalyst for a three-component reaction of amines, aldehydes, and alkynes (A3 coupling). A diverse range of propargylamines were obtained in good yields. Furthermore, the separation and recycling of Au/S. lavandulifolia NPs was very simple, effective, and economical.

Microwave assisted one pot three component synthesis of propargylamine, tetra substituted propargylamine and pyrrolo[1,2-a]quinolines using CuNPs@ZnO–PTh as a heterogeneous catalyst

A Cu@ZnO–PTh nanocomposite was synthesized and used as a heterogeneous catalyst for KA² and A³ coupling, which is a highly efficient and green technique.

Tunable Prussian blue analogues for the selective synthesis of propargylamines through A3 coupling

M¹[Co(CN)₆]_2/3-type Prussian blue analogues (M¹–Co PBAs) were studied as catalysts for the synthesis of propargylamines via A³ coupling of phenylacetylene, benzaldehyde and piperidine.

Anchorage of Au3+ into Modified Isoreticular Metal-Organic Framework-3 as a Heterogeneous Catalyst for the Synthesis of Propargylamines

Postsynthetic modification of metal-organic framework is a general and practical approach to access MOF-based catalysts bearing multiple active sites. The isoreticular metal-organic framework-3 (IRMOF-3) was modified with lactic acid through condensation reaction of the carboxyl group of lactic acid and amino group present in IRMOF-3 frameworks. Au3+ was subsequently anchored onto the metal-organic framework IRMOF-3 using postsynthetic modification. The synthezized IRMOF-3-LA-Au (LA = lactic acid) was characterized by powder X-ray diffraction, N2 adsorption-desorption, infrared spectroscopy, liquid-state nuclear magnetic resonance, thermogravimetric analysis, H2-temperature programmed reduction, transmission electro microscopy, and inductively coupled plasma-optical emission spectrometry. IRMOF-3-LA-Au acted as an efficient heterogeneous catalyst in the synthesis of propargylamines by three-component coupling reaction of aldehyde, alkyne, and amine. Moreover, the catalyst is applicable to various substituted substrates, including aromatic and aliphatic aldehydes, alkyl- and aryl-substituted terminal alkynes, and alicyclic amines. In addition, the catalyst can be easily separated from the mixture and can be reused for four consecutive cycles.

Au3+/Au⁰ Supported on Chromium(III) Terephthalate Metal Organic Framework (MIL-101) as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines

Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs). A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde), containing coexisting Au³⁺ ions and Au⁰ nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101) were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N₂ adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au³⁺/Au⁰ = 0.9) and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

Copper-coordination polymer-controlled Cu@N-rGO and CuO@C nanoparticle formation: reusable green catalyst for A3-coupling and nitroarene-reduction reactions

Cu/CuO NPs were fabricated in N-rGO/carbon matrices using structural versatility of coordination polymers and utilized as reusable green catalyst.