FR-900482 is a new antitumor antibiotic produced by a new actinomyces named Streptomyces sandaensis No. 6897. It exhibits potent cytotoxic activity against various tumor cells in vitro. Furthermore, it has weak antimicrobial activity against some Gram-positive or

The structure of two new marine carotenoids, isolated from the tunicate, Amaroucium pliciferum, and designated as amarouciaxanthin A and B, were determined on the basis of chemical and spectral data. Amarouciaxanthin A was determined as (6S, 3'S, 5'R,6'R)- 6,3',5'-trihydroxy-4,5,6',7'-tetradehydro-7,8,5',6'-tetrahydro-beta, beta-carotene-3,8-dione, and Amarouciaxanthin B was determined as (6S,3'R)-6,3'-dihydroxy-4,5,7',8'-tetradehydro-7,8-dihydro-beta,beta- carotene-3,8-dione. These two compounds are also presumed to be new metabolic products of a typical marine carotenoid, fucoxanthin.

No abstract

Biphenomycin A, C23H21N4O8, and biphenomycin B, C23H28N4O7, were isolated from the cultured broth of Streptomyces griseorubiginosus No. 43708. The antibiotics are active in vitro and in vivo against bacteria, and are especially potent against Gram-positive bacteria. The acute toxicity of biphenomycin A is very low in mice.

No abstract