CHEMICAL STUDY AND ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF THE ASCIDIAN Clavelina oblonga

Purpose: Marine organisms produce a variety of structurally novel and pharmacologically interesting compounds. In this work the ascidian Clavelina oblonga (Clavelinidae) was selected for study. Methods: After collection (previously authorized by the Ministry of Environment -MMA n. 34958-2), the fresh material was extracted in methanol by maceration to obtain the respective crude extract (CO) which was analyzed by HPLC-DAD and 1 H-NMR and then subjected to the purification by cyclic column using the PSDVB polymer stationary phase to give the fractions CO-A to CO-F. The mobile phase used was mixtures of water and acetone (20% -100%). The obtained fractions were analyzed by TLC and HPLC-DAD and also submitted to antimicrobial and cytotoxic assays. Results: The chromatographic procedure performed with CO extract afforded fractions with different chemical profile. In the antimicrobial assay, the CO-D fraction was the most promising, showing inhibitory action against the bacteria Streptococcus mitis at a concentration of 50 µg/mL and also inhibited the strains Streptococcus bacteria (ATCC 10556 and clinical isolate) and Streptococcus oralis (clinical isolate) at the concentration of 100 μg/ml. Despite the cytotoxic assay, the CO-D fraction showed cytotoxicity to normal human fibroblast cells GM07492A with IC 50 of 45.8 ± 11.0 µg/mL. Conclusion: These results will lead the sequence of chemical research looking for the active compounds of C. oblonga.