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Lignin is a biodegradable, non-toxic, and renewable biopolymer. The present investigation focuses on the bio-fabrication of superparamagnetic iron oxide nanoparticles (Li-SPIONs) using lignin from agro-wastes (straw of paddy and wheat) as a capping and reducing agent. The main motive of this study is to produce the biopolymer mediated nanomaterials using lignin. It is very important and needed in medicinal field as biodegradable nano drug delivery vehicles. Lignin mediated biogenic iron oxide nanomaterials were characterized by various techniques. An analysis of Field Emission Scanning Microscopy and High-Resolution Transmission Electron Microscope reveals that spherical-shaped Lignin mediated biogenic iron oxide nanomaterials were 20 ± 2 nm and 32 ± 4 nm in size respectively. The vibrating-sample magnetometer analysis illustrates that the bio-synthesized nanoparticles contain saturation magnetization. The lignin and their functional groups are act as capping and reducing/stabilizing agent for formation of biogenic iron oxide nanomaterials with magnetic power. In addition, this study was to explore Lignin mediated biogenic iron oxide nanomaterials for antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl assay. The IC50 values of the DPPH assay were as follows, 60 μg/mL (PLi-SPIONs) and 62 μg/mL (WLi-SPIONs). The rate of percent free radical inhibition was 59.85% determine its maximum antioxidant potential. Biogenic iron oxide nanomaterials were able to deactivate the free radicals and oxidative metabolites. It clearly shows that biogenic iron oxide nanomaterials have good magnetic and antioxidant properties, which could be used to produce and formulate novel drug and biomedical applications.

An eco-friendly, low toxic and facile synthetic approach was employed to produce superparamagnetic biogenic iron oxide nanoparticles (SPBIONs) using an aqueous extract of tea-pruning waste as a reducing agent under alkaline conditions. As-biosynthesized SPBIONs were extensively characterized by various analytical tools. For instance, XRD pattern showed crystallinity and FTIR spectra revealed the presence of bioactive molecules required for the reduction of iron oxide ions. AFM and FESEM-EDX images showed agglomerated spherical shape with strong signals of iron metallic ions. The average crystallite sizes of SPBIONs were found to be 20–35 nm by HRTEM analysis. Zeta potential analysis confirmed that the surface charge of the green synthesized SPBIONs was highly negative (−25.2 mV) and stable. TGA curve reported a weight loss of 14%, which occurred in SPBIONs over temperatures ranging from 50 °C to 950 °C due to the removal of water molecules and volatile compounds. VSM analysis revealed that SPBIONs exhibited superparamagnetic properties with a high-saturation magnetization value of 11 emu/g. In addition, the antioxidant property of SPBIONs was investigated with 1,1-Diphenyl-2-picrylhydrazyl (DPPH), a free radical assay, and it was seen that 70 μg/mL (IC50) of SPBIONs was able to neutralize the generation of free radicals and oxidative stress. The present study successfully demonstrated that utilization of tea resources for the production of SPBIONs with superparamagnetic and antioxidant properties might be used to design antioxidant agents and other biomedical applications.

Pruning is a routine management practice in tea cultivation. Although pruning is speculated to contribute to shoot growth and development in tea plants, it is imperative to understand the molecular mechanism involved. In order to investigate this, tea plants were pruned at different levels. Analysis of shoot growth indices revealed significant increase in shoots number and weight in shoots of pruned tea plant. Auxin assay showed higher concentrations of indole-3-acetic acid in pruned samples. Metabolomic analysis identified 80 differential metabolites in shoots of pruned plants, of which indole-3-acetonitrile and menaquinone were the common metabolites in all levels of pruning. The metabolites are involved in auxin biosynthesis, as shown by protein-protein interaction analysis. The metabolites enriched major metabolic pathways such as tryptophan metabolism, vitamin digestion and absorption, biosynthesis of ubiquinone and other terpenoid-quinone, and biosynthesis of amino acids. Genes involved in auxin signalling and menaquinone synthesis were up-regulated in pruned plants. This study reports, for the first time in nature, the synthesis of menaquinone in plants. This study concludes that pruning enhances shoot growth and development through the modulation of indole-3-acetic acid via synthesis of indole-3-acetonitrile and menaquinone in shoots, a combined effect of tryptophan metabolism and other metabolic pathways. This study contributes to knowledge in molecular mechanism of shoot growth and development.

Zinc oxide nanoparticles were synthesized by biological method using aqueous extract of Lantana aculeata leaf and characterized by UV-visible spectroscopy, XRD, FTIR, FESEM, HRTEM and EDX analysis. The synthesized particles were highly stable and spherical, and particle size was in the range of 12–25 nm. The cytotoxicity activity of Lantana aculeata-mediated zinc oxide nanoparticles was evaluated by MTT assay against SiHa cervical cancer cell lines and confirmed that zinc oxide nanoparticles have cytotoxicity activity. The genotoxicity of ZnO nanoparticles was evaluated using comet assay and DNA laddering technique. ZnO nanoparticles in Sesamum indicum is yet to be confirmed in the comet assay and DNA laddering experiments. We detected increased level of DNA damage in concentration at 2000 mg L−1 treatment dose of ZnO nanoparticles in Sesamum indicum. The study thus confirms the toxicity potential of ZnO nanoparticles in both plant and human cancer cell line.