7 抗カビ抗生物質ホシダマイシンの化学構造に関する研究

抄録

An antibiotic, hondamycin (I), which showed the activity against the plant pathogenetic fungi including Piricularia oryzae in vitro, was produced from Streptomyces griseochromogenes var. albicus. The antibiotic was obtained as a hexagonal plate, mp.149-150(dec), from mycelia in culture. Hondamycin has C_<47>H_<78>O_<13> as the molecular formula. The maximums of the ultraviolet spectrum for (I) in methanol showed at 225mμ and 232.5mμ and, shoulders at 219mμ and 240mμ. Infra-red analysis indicated the presence of hydroxyl groups, lactone group and carbonyl group. Chemical studies showed that hondamycin have three carbon-carbon double bonds, three secondary hydroxyl groups, a conjugated lactone group, carbonyl groups, tirtiary hydroxyl groups and ten C-methyl groups as funitional groups, and the substance (I) consumed two moles of periodate to give about two moles of acetaldehyde and the acid (II). On oxidation of hondamycin (I) and the acid (II) with ozone there gave aldehyde (IV), C_<25>H_<50>O_7 and glyoxal. This aldehyde was changed to the polyol (VI), C_<25>H_<50>O_6. On oxidation of hondamycin with ozone there gave the polyol (V), C_<18>H_<38>O_8, too. Compound (V) and (VI) was oxidized with chromic acid and potassium permanganate. The antibiotic gave tiglicaldehyde on hydrolysis with methanolic sodium hydroxide. From the results of N.M.R. spectrums and chemical reactions for these partial structure of hondamycin it was understood the chemical structure of hondamycin as figure.