Masataka Konishi

Lanthiopeptin, a new peptide effective against herpes simplex virus: Structural determination and comparison with Ro 09-0198, an immunopotentiating peptide

Abstract The structure of lanthiopeptin, a new lanthionine peptide effective against Herpes virus, was newly determined. It has a unique tetracyclic sequence which is very similar to but different from the proposed structure for Ro 09-0198. However, Ro 09-0198 was found to be quite the same compound as lanthiopeptin in all respects.

Terpestacin, a novel syncytium formation inhibitor, isolated from Arthrinium species

Abstract Terpestacin a novel syncytium formation inhibitor in HIV infection, was isolated from Arthrinium sp. metabolites. The structure of terpestacin including the absolute stereochemistry was determined on the basis of spectroscopic analysis and chemical reactions. The biosynthetic pathway of terpestacin was also determined.

A total synthesis of 6,7-dihydroeponemycin and determination of stereochemistry of the epoxide ring

Abstract A total synthesis of 6,7-dihydroeponemycin 2 was achieved via the epoxide intermediate 8a . Unresolved absolute configuration of the epoxide ring in 2 and eponemycin 1 was determined to be 2 R by application of the asymmetric Sharpless epoxidation of 9 .

Absolute configuration of the rubiginones and photo-induced oxidation of the C1 hydroxyl of the antibiotics to a ketone

The absolute stereochemistry of rubiginones A1, A2, B1, B2, C1 and C2 has been established by NMR spectral analysis using the O-methylmandelate method. A facile photoinduced oxidation of rubiginones A1, B1 and C1 to rubiginones A2, B2 and C2, respectively, is discussed in relation to the absolute stereochemistry.

Facile reductive rearrangement of dynemicin A to dynemicin H : the direct evidence for the p-phenylene diradical intermediate

Dynemicin A rearranged smoothly to dynemicin H, on treatment with aqueous sodium hydrosulfite in dioxane. The same reaction in d8-dioxane gave dynemicin H deuterated specifically at 24- and 27-positions indicating the generation of biradical species at these positions.