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ObjectiveTo isolate and characterize the bioactive secondary metabolite from Callyspongia spp. associated fungi.MethodsIn vitro antibacterial screening of fungi associated with Callyspongia species, collected from south east coast of India, against selected clinical isolates of bacteria were conducted in this study. The extracts showing good antimicrobial activity were subjected to further analysis to identify the active constituents sponge associated fungi (both biomass and filtrate) with five different solvents. The compound responsible for bioactivity was characterized using Fouvier-transform infrared (FT-IR) and gas chromatography-mass spectrometry (GC-MS) instrumental analysis to identify the functional group and compound. The molecular characterization of the elite fungal strains were done by isolating their genomic DNA and amplify the internal transcribed spacer (ITS) region of 5.8 sr RNA using specific ITS primer. The novelty of the strain was proved by BlastN analysis against non-redundant (NR) database and hence was submitted to GenBank.ResultsActive compound was Desmethylnomifensine confirmed by GC-MS and the potent fungi was Aspergillus flavus GU815344.ConclusionsThe isolate exhibits a marked antagonistic activity against potential bacterial pathogens thus illuminating the advanced researches in this decade to focus on clinical pharmacology to identify novel therapeutic targets. The present study depicts a promising scenario to focus on Aspergillus flavus derived compounds which can be easily scaled up for large biomass production and stable formulation as a drug.

Objective: To explore antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis (A. officinalis). Methods: In the present study the leaf extracts of A. officinalis were examined for its antibacterial potential using five different solvents against some reference strains of human pathogenic bacteria for the crude extract. Maximum activity was observed for ethyl acetate and hence different concentrations like 15 μL, 25 μL, and 50 μL of ethyl extracts was checked for its antibacterial activity. Partial purification of crude extract was earned by column chromatography and fractions were analyzed using gas chromatography-mass spectrometry (GC-MS) to identify compounds. Results: The crude ethyl acetate extracts of A. officinalis showed remarkable antibacterial activity with zones of inhibition of 13 mm against Eschericia coli (E. coli) and 11 mm against Staphylococcus aureus (S. aureus). Fraction 13 (ethyl acetate: methanol= 8:2) as the most potent one against with the minimal inhibitory concentration of 30 mm against E. coli and 25 mm against S. aureus. The GC-MS resultsof active column fraction (F13) revealed that the active principals were a mixture of hydroxy-4 methoxybenzoic acid, diethyl phthalate, oleic acid. Conclusions: The leaf extracts with proven antibacterial effects can clearly be directed towards cancer treatment as to inhibiting cancer cell growth. The limited number of test organisms owes to a constraint of resource. So, the effect of strong bursts of leaf extracts on human pathogenic bacteria should further be tested on a wide range of test organisms.