School of Bioscience and Technology

The aim of the present study was to assess the larvicidal property of marine actinobacterial compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one (DMBPO) extracted and isolated from Streptomyces VITSVK5 sp. tested against the larvae of Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae), Anopheles stephensi Liston, and Culex tritaeniorhynchus Giles (Diptera: Culicidae). The isolate bacteria was taxonomically characterized, identified, and designated as Streptomyces VITSVK5 sp. The crude extract was loaded on silica gel column and eluted with chloroform:methanol. The isolated pure compound was analyzed by thin layer chromatography using chloroform and methanol as the solvent system and confirmed by high-performance liquid chromatography. The structure of the purified compound was established from infrared, ultraviolet, 1H-nuclear magnetic resonance (NMR), 13C-NMR, and mass spectral data. The chemical shift assignments obtained for the aliphatic compound from 1H-NMR corresponding to the molecular formula C13H17NO. Bioassay-guided fractionation led to the isolation of compound which was identified as DMBPO. In the present study, Streptomyces VITSVK5 sp. crude extract and different fractions were tested against the larvae of parasites at the concentration of 1,000 ppm. Those fractions showing 100% mortality in 24 h alone was selected for further column chromatographic separation. The purified compound, C13H17NO, was tested in the concentrations of 500, 250, 125, 62.5, and 31.25 ppm and observed the percent larval mortality of 100, 70, 64, 40, and 28 against R. microplus; 100, 79, 63, 36, and 22 against A. stephensi; and 100, 84, 67, 42, and 27 against C. tritaeniorhynchus, respectively. The crude extract showed parasitic effects after 24 h of exposure at 1,000 ppm, and parasite mortality was observed against the larvae of R. microplus (LC50 = 210.39 ppm, r 2 = 0.873); A. stephensi (LC50 = 169.38 ppm, r 2 = 0.840); and C. tritaeniorhynchus (LC50 = 198.75 ppm, r 2 = 0.887). The maximum efficacy was observed in purified marine actinobacterial compound DMBPO with LC50 and r 2 values against the larvae of R. microplus (84.31 ppm, 0.889); A. stephensi (88.97 ppm, 0.817), and C. tritaeniorhynchus (74.95 ppm, 0.781), respectively. The control (distilled water) showed nil mortality in the concurrent assay.

Heavy metal pollution is one of the most important environmental problems today. Biosorption is an innovative technology that employs biological materials to accumulate heavy metals from waste water through metabolic process or physicochemical pathways of uptake. Even though several physical and chemical methods are available for removal of heavy metals, currently many biological materials such as bacteria, algae, yeasts and fungi have been widely used due to their good performance, low cost and large quantity of availability. The aim of the present study is to explore the biosorption of toxic heavy metals, Cr(VI), Cr(III), Pb(II) and Cd(II) by algal biomass obtained from algae Sargassum wightii (brown) and Caulerpa racemosa (green). Biosorption of algal biomass was found to be biomass concentration- and pH-dependent, while the maximal biosorption was found at pH 5.0 and with the metal concentration of 100 mg L−1. S. wightii showed the maximal metal biosorption at the biomass concentration of 25 g L−1, followed by C. racemosa with the maximal biosorption at 30 g L−1. S. wightii showed 78% biosorption of Cr(VI), Cr(III), Pb(II) and Cd(II) ions. C. racemosa exhibited 85% biosorption of Cd(II) and Cr(VI), and 50% biosorption of Cr(III) and Pb(II). The results of our study suggest that seaweed biomass can be used efficiently for biosorption of heavy metals.

The criteria used for successful drug discovery involves high throughput screening for preclinical evaluation and its interaction with target enzymes. In silico approach resulting in the creation of drug like library and identification of essential reactions and pathways spreads across several parts of metabolism. The aim of the present study was to evaluate the preclinical property and interaction to various drug target enzymes for spiroindimicins A-D and lynamicin A and D isolated from deep marine sea derived Streptomyces sp. SCSIO 03032 with 7 selected drug target enzymes. The preclinical and molecular docking simulation was performed using In silico pharmacology and docking tool. Drug likeliness, ADME and toxicity testing findings suggested the compounds with oral drug candidate's probability. Interaction of isolated compounds against drug target enzymes was satisfactory with Spiroindimicins C, D and Lynamicin D emerging as most potent Topoisomerase II, Cathepsin K, Cytochrome P4503A4, Aromatase P450, protein kinase and histone deacetylase inhibitors. Our results suggest that In silico approach in drug discovery procedure in later stage of development can ease up making lead molecules library.