HR-LC-MS based analysis of two antibacterial metabolites from a marine sponge symbiont Streptomyces pharmamarensis ICN40

- Streptomyces pharmamarensis ICN40 was isolated and identified from the marine sponge Clathria procera.
- Antibacterial screening and bioassay guided isolation yielded two unknown compounds PVI401 and PVI402 based on HR-LC-MS.
- Antibacterial efficacy and anti-MRSA biofilm activity is reported for the compound PVI401.
- The whole organism zebrafish safety evaluations were studied for the compounds.

On the effort to screen antibiotics against Methicillin resistant Staphylococcus aureus (MRSA), an actinomycete strain which can produce bactericidal compound was isolated from a marine sponge of Kanyakumari Coast, India. Two anti-MRSA compounds (PVI401 and PVI402) were isolated from the fermentation plates of Streptomyces pharmamarensis ICN40. TLC bioautography analysis yielded two active spots with Rf value of 0.75 (PVI401) and 0.8 (PVI402) from the crude extract. Both the compounds were characterized by HR-LC-MS analysis. LC-MS based de-replication analysis found out the compound PVI401 with an exact mass of 376.09435 Da and PVI402 with an exact mass of 273.26795 Da were found to be unidentified. Antibacterial spectrum showed significant minimal inhibitory concentration as 0.5 μg/ml of PVI401 and 2 μg/ml of PVI402 against MRSA. The whole organism zebrafish safety evaluation exhibited the compound PVI402 is safe upto 1 mg/ml 40 μg/ml of PVI401 exhibited thrombosis in cardiac chamber and this compound exhibited 44 μg/ml of LC50 against HepG2 hepatic carcinoma cell line. Both the compounds may be identified further for its structural novelty and clinical studies.

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