New metabolites, tetrahydrofuran lignans, produced by Streptomyces sp. IT-44.

During the course of our screening for new antibiotics, we utilized sesame meal, a waste material from the industrial production of sasame oil, as a nitrogen source for growth of strains of Actinomycetes. An isolate of Streptomyces sp. IT-44 showed antibacterial and antitumor activities. Bioassay-guided fractionation of the broth filtrate of Streptomyces sp. IT-44 led to the isolation of three furofuran lignan-type antibiotics, determined as pinoresinol (1), epipinoresinol (2) and a new compound 3. Four related compounds, piperitol (4), sesaminol (5), sesamin (6) and a new piperonyloyl