Biogenic synthesis of Mn3O4 NPs using Phyllanthus emblica leaf extract for electrochemical sensing of urea

There are many methods to synthesise metal and metal oxide nanoparticles (NPs) using different reducing agents which are hazardous in nature. Although some researchers have used biobased materials for synthesis of these NPs, further research is needed in this area. To explore the scope of bio-extract for the synthesis of transition metal NPs, the present paper synthesises metal NPs replacing hazardous traditional reducing agents. This paper reports the synthesis of palladium and iron NPs, using aqueous extract of Terminalia chebula fruit. Reduction potential of aqueous extract of polyphenolic rich T. chebula was 0.63V vs. SCE by cyclic voltammetry study which makes it a good green reducing agent. This helps to reduce palladium and iron salts to palladium and iron NPs respectively. Powder X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) analyses revealed that amorphous iron NPs were within the size less than 80 nm and cubic palladium NPs were within the size less than 100 nm. The synthesised nanomaterials were remarkably stable for a long period and synthesis of stable metal NPs will need to be explored using biobased materials as reducing agents.

The plants of the genus Phyllanthus (Euphorbiaceae) are widely distributed in most tropical and subtropical countries, and have long been used in folk medicine to treat kidney and urinary bladder disturbances, intestinal infections, diabetes, and hepatitis B. In recent years, the interest in the plants has increased considerably. Substantial progress on their chemistal and pharmacological properties, as well as a few clinical studies of some Phyllanthus species have been made. This review discusses the current knowledge of their chemistry, the in vitro and in vivo pharmacological, biochemical, and clinical studies carried out on the extracts, and the main active constituents isolated from different species of plants of the genus Phyllanthus. These studies carried out with the extracts and purified compounds from these plants support most of their reported uses in folk medicine as an antiviral, in the treatment of genitourinary disorders, and as antinociceptive agents. However, well-controlled, double-binding clinical trials are lacking. Several compounds including alkaloids, flavonoids, lignans, phenols, and terpenes were isolated from these plants and some of them interact with most key enzymes. Together this data strongly supports the view that the plants belonging to the genus Phyllanthus have potential beneficial therapeutic actions in the management of hepatitis B, nefrolitiase, and in painful disorders.