13 微生物由来の新規抗酸化物質benthocyaninに関する研究(口頭発表の部)

抄録

Antioxidative substances may prevent a variety of diseases caused by active oxygen species. In the course of our screening program for antioxidants of microbial origin, we have isolated three new active substances, named benthocyanins A, B and C, from the cultured broth of an actinomycete identified as Streptomyces prunicolor. The molecular formulas of benthocyanins A, B and C were determined as C_<31>H_<28>N_2O_4, C_<31>H_<28>N_2O_4 and C_<31>H_<29>N_3O_3, respectively, by high resolution FAB-MS. The structure of benthocyanin A was elucidated by using a variety of two-dimensional NMR techniques and confirmed by X-ray crystallographic analysis as shown in Fig. 1. The structures of benthocyanins B and C were also determined as shown in Fig. 1 on the basis of spectral comparison with benthocyanin A and NMR analysis. The structures of the benthocyanins are characterized by a new modified phenazine skelton with geranyl and phenyl residues. Benthocyanins A, B and C inhibited lipid-peroxidation in rat liver microsomes with IC_<50> values of 0.60 μg/ml, 0.07 μg/ml and 0.67 μg/ml, respectively.