Nuclear magnetic resonance and biosynthetic studies of neoantimycin and structure elucidation of isoneoantimycin, a minor metabolite related to neoantimycin.
In preparation for biosynthetic studies on the 3,4-dihydroxy-2, 6-dimethyl-5-phenylvaleric acid portion of neoantimycin (1), the 1H and 13C NMR signals of 1 were assigned unambiguously by means of 2D correlation spectroscopy and NOE experiments. The previously undetermined absolute stereochemistry at C-15 and C-16 was deduced as (S) and (S). The structure of isoneoantimycin (2) was also elucidated. The methyl groups of methionine and propionate were incorporated stereospecifically into C-13 and C-12 of 1, respectively, and the configuration of the methyl group of methionine is inverted in the process. The results also suggest the intervention of phenylpyruvate as an actual precursor.
Takeda
Y
Y
Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770, Japan. takedaias.tokushima-u.ac.jp
Masuda
T
T
Matsumoto
T
T
Takechi
Y
Y
Shingu
T
T
Floss
H G
HG
D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry*; D001711:Biotransformation; D003470:Culture Media; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D009930:Organic Chemicals; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013302:Streptomyces / Q000378:metabolism
D000900:Anti-Bacterial Agents; D003470:Culture Media; D009930:Organic Chemicals; C002699:neoantimycin