Isolation and structural elucidation of an antioxidative agent, naphterpin.

Active oxygen species cause a variety of diseases such as inflammation, autoimmune disease, diabetes, rheumatism, cardiovascular diseases and cancer-initiation1>2). Thus, it could be expected that antioxidative agents may prevent these diseases. We have screened antioxidants of microbial origin by employing the Yagi method after minor modification using rat liver microsome free from vitamin E3). As a result, we succeeded in isolating a new antioxidative agent, named naphterpin. In this paper, we report the fermentation, isolation and structure determination of naphterpin. The producing microorganism Streptomyces sp. CL190 was isolated from Ishigaki Island, Okinawa Prefecture, Japan. It was inoculated into test tubes containing 12ml of the seed medium consisting of glucose 2.5%, soybean meal 1.5%, dry yeast 0.2% and CaCO3 0.4% (pH 6.2, before sterilization). After incubation at 27°Cfor 2 days on a reciprocal shaker, an aliquot of the broth (2ml) was transferred into 500-ml Erlenmeyer flasks each containing 100 ml of the samemediumas the seed culture and incubated at 27°C for 2 days on a rotary shaker. The