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.
Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770, Japan. takedaias.tokushima-u.ac.jp
Y
Y
Takeda
T
T
Masuda
T
T
Matsumoto
Y
Y
Takechi
T
T
Shingu
H G
HG
Floss
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