Absolute configuration-dependent epoxide formation from isoflavan-4-ol stereoisomers by biphenyl dioxygenase of Pseudomonas pseudoalcaligenes strain KF707

作者：Seo Jiyoung; Kang Su Il; Won Dongho; Kim Mihyang; Ryu Ji Young; Kang Suk Woo; Um Byung Hun; Pan Cheol Ho; Ahn Joong Hoon; Chong Youhoon; K****y Robert A; Han Jaehong; Hur Hor Gil^*

来源：Applied Microbiology and Biotechnology, 2011, 89(6): 1773-1782.

DOI：10.1007/s00253-010-2989-1

• Biphenyl dioxygenase
• Pseudomonas pseudoalcaligene
• Isoflavanol epoxide
• Pterocarpan
• Medicarpin

Biphenyl dioxygenase from Pseudomonas pseudoalcaligenes strain KF707 expressed in Escherichia coli was found to exhibit monooxygenase activity toward four stereoisomers of isoflavan-4-ol. LC-MS and LC-NMR analyses of the metabolites revealed that the corresponding epoxides formed between C2' and C3' on the B-ring of each isoflavan-4-ol substrate were the sole products. The relative reactivity of the stereoisomers was found to be in the order: (3S,4S)-cis-isoflavan-4-ol > (3R,4S)-trans-isoflavan-4-ol > (3S,4R)-trans-isoflavan-4-ol > (3R, 4R)-cis-isoflavan-4-ol and this likely depended upon the absolute configuration of the 4-OH group on the isoflavanols, as explained by an enzyme-substrate docking study. The epoxides produced from isoflavan-4-ols by P. pseudoalcaligenes strain KF707 were further abiotically transformed into pterocarpan, the molecular structure of which is commonly found as part of plant-protective phytoalexins, such as maackiain from Cicer arietinum and medicarpin from Medicago sativa.

• 出版日期2011-3