摘要
Bioassay guided purification of the acetone extract of the marine sponge, Haticlona exigua, (Gulf of Mannar, India) yielded a fraction rich in bis-1-oxaquinolizidine alkaloids, active against seven strains of fouling bacteria as well as cyprids of the cosmopolitan barnacle, Balanus amphitrite. The major alkaloids in the mixture have been tentatively identified as nor-araguspongine C (33.76%), araguspongine C (6.49%), dihydroxy araguspongine (36.36%), methyl and dimethyl derivatives of the latter (12.98 and 10.38%, respectively) from HRMS studies. The lower EC50 (6.6 mu g/ml as against the US Navy standard of 25 mu g/ml for NPAs) and low toxicity (LC50 IS mu g/ml as compared to 0.00001 mu g/ml for TBT) values, coupled with its favourable therapeutic ratio (2.7 as against the requirement of >1) makes these compounds ideal NPAs in environmentally compatible antifouling coatings.
- 出版日期2009-1