Characterization of cytotoxic compound from marine sediment derived new actinomycete Streptomyces coelicolor strain SU5

In the search of novel anticancer compounds we have taken an initiative to isolate halophilic actinomycetes from Tamilnadu coast. Fifty-two actinomycetes were isolated from the coastal soil samples of Pulicat, Ennore, Muttukadu, and Veerampattinam. Out of 52 isolates only 10 were subjected to brine shrimp lethality assay and one of the most potent cytotoxic isolate, which is the inhabitant of Veerampattinam was studied further. Crude extract of the active isolate exhibited LC50 in 62.5 µg against Hep-2 cell line, < 250µg in VERO cell line. The crude extract was purified by TLC and then characterized by using GC-MS. The following compounds diisobutyl phthalate (16.82%) and 1,2-Benzenedicaarboxylic acid, Bis(2-ehtylehexyl) ester (65.26%) were found abundantly with retention time 15.645, 21.620 respectively. Morphological, cultural, physiological, biochemical assay and 16s rRNA sequencing results the active strain was identified as Streptomyces and closely related to the species Streptomyces coelicolor also submitted to GENBANK. It is inferred that Streptomyces coelicolor strain SU5 producing anticancer compounds and these may be processed further for its commercial application. This study clearly proves that the marine sediment derived actinomycetes with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical and anticancer screening programs.