The antibiotic SS-228Y (l), obtained from a species of Chainia isolated from shallow sea mud, is known to inhibit the growth of Gram-positive bacteria and dopamine-& hydroxylase and is very labile to light and heat, being converted into SS-228R (2)(Scheme I). l Their structures had been deduced by spectroscopic data, especially by (1)(a) Okazaki, T.; Kitahma, T.; Okami, YJ Antibiot. 1976, 28, 176.(b) Kitahara, T.; Naganawa, H.; Okazaki, T.; ...