UCH9, a new antitumor antibiotic produced by Streptomyces. II. Structure elucidation of UCH9 by mass and NMR spectroscopy

• Published in: Journal of antibiotics Vol. 51; no. 3; p. 267
• Main Authors: Katahira, R, Uosaki, Y, Ogawa, H, Yamashita, Y, Nakano, H, Yoshida, M
• Format: Journal Article
• Language: English
• Published: Japan 01-03-1998
• Subjects: Antibiotics, Antineoplastic - chemistry; Dimerization; Magnetic Resonance Spectroscopy; Mass Spectrometry; Plicamycin - analogs & derivatives; Plicamycin - chemistry; Streptomyces - metabolism
• ISSN: 0021-8820
• DOI: 10.7164/antibiotics.51.267

The structure of UCH9, which is a novel antitumor agent, was determined by spectroscopic methods. UCH9 consists of an aglycone and five 2,6-dideoxy sugars (three D-olivoses, one 4-O-methyl-D-olivose and one D-oliose). Four of the five sugars are sequentially connected through a beta 1-->3 linkage (olivose-1-->3-4-O-methyl-olivose-1-->3-oliose-1-->3-+ ++olivose). On the basis of the results of spectroscopic analysis, it was found that UCH9 belongs to the aureolic acid family of antibiotics. The structure of UCH9 is unique in that mono- and tetrasaccharide moieties, and a long hydrophobic side chain (sec-butyl group) are attached to the aglycone, while di- and trisaccharide moieties and a methyl or a hydrogen are attached in the case of the known aureolic acid analogs. It is known that aureolic acid analogs from a dimer in the presence of Mg2+. NMR, FAB-MS and atomic absorption analysis revealed that UCH9 isolated from Streptomyces also forms a dimer, containing one equivalent molar Mg2+.