The structure of SS-228Y, an antibiotic from Chainia Sp.

As reported in a previous paper1), SS-228 Y is an antibiotic produced by an actinomycete, Chainia sp. The antibiotic is active against Gram-positive bacteria and inhibits dopamine /9hydroxylase. In this paper, the structural studies on SS-228Y and a derivative, SS-228 R obtained from its photolysis or thermolysis are described. SS-228 Y (I) is an orange powder [m.p. 256-266°C, dec., [a]D-85° (c 1.0, acetone)] having a molecular formula of C19H14O6 (mol. wt. 338, elemental analysis and mass spectrum, m/e 320, M+-H2O1)). The ultraviolet and visible absorption spectra of I are as follows: 280%MeOH max(nm) 218 (e 22000), 228sh (e 21800), 415 sh (s 4000), 440-460 (s 4100), and 2 0.2NNaOH-80%MeOH (nm) 269 (s 17900), 408 (s 6400), 552 (s 4400). The IR spectrum of I indicated the presence of an a, /9unsaturated carbonyl (1680 cm-1), a quinone carbonyl (1665 cm-1) and a chelated quinone carbonyl (1630 cm -1). The NMR spectrum (d4-methanol) of I displayed the following signals: 8 CH3 H 1.93 (3H, s, sharpened on irradiation at 6 6.12, C=C 5 2.68 (2H, broad s), 5 6.12