Sanraku Incorporated

Osamu Jodo

Tomio Takeuchi

Akihiro Yoshimoto

Yoshio Watanabe

Tomoyuki Ishikura

Tsutomu Sawa

Rokuro Okamoto

Hamao Umezawa

Hiroshi Naganawa

Hamao Umezawa, Deceased

This invention relates to a process for preparing an antibiotic D788-7 wherein, after culturing carborubicin-producing bacteria, the obtained culture liquid is extracted in acidic conditions while stirring to be absorbed to synthetic resin, followed by desorption from the resin and elution with acetone and the resulting acetone solution containing carborubicin is converted into an antibiotic D788-7 by photo radiation, for obtaining D788-7 in the purified form from the reaction solution. The production yield for D788-7 is extremely high and its use as an antitumor agent can be made possible.

Process for preparing antibiotics D788-7

Disclosed are anthracycline antibiotics of a formula (I): ##STR1## in which R.sup.1 and R.sup.2 are hydroxyl groups, R.sup.3 is ethyl group, R.sup.4 is methoxycarbonyl group and X represents daunosamine-rhodenose or daunosamine-deoxyfucose; or

Anthracycline antibiotics

New anthracycline antibiotics of a formula (I) are provided, which are usable as an anticancer agent ##STR1## (where R represents a hydrogen atom or a hydroxyl group). The antibiotics (I) can be produced by incubation of a dye-nonproductive or hardly dye-productive mutant strain which has an ability of converting .alpha.-citromycinone or .beta.-isorhodomycinone into the antibiotics (I), in the presence of .alpha.-citromycinone or .beta.-isorhodomycinone in a pertinent nutrient medium.

Anthracycline antibiotics DCP-1 and 2

The antibiotics designated obelmycins exhibit high proliferation inhibiting action against leukemia cells and are effective as anti-cancer agents.

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Yokohama, Japan

Osamu Jodo