... ca HIROKI TSUKAMOTO, SUEO HISADA, and SANSEI NiSHiBE* Faculty of Pharmaceutical Sciences, Higashi ... 13C-NMR Chemical Shifts” S-Methoxylation (A 5) 6-O-Methy1ation (A5) 9 ... M. Nagai of the Institute of Medicinal Chemistry, Hoshi University, for valuable suggestions ...