Studies on the late steps of (+) pisatin biosynthesis: Evidence for (−) enantiomeric intermediates
作者:G DICENZO、H VANETTEN
DOI:10.1016/j.phytochem.2005.12.027
日期:2006.4
Pisatin, a 6a-hydroxyl-pterocarpan phytoalexin from pea (Pisum sativum L.), is relatively unique among naturally occurring pterocarpans by virtue of the (+) stereochemistry of its 6a-11a C-C bond. However, pisatin synthesizing pea tissue has an isoflavone reductase, first identified in alfalfa, which acts on the (-) antipode. In order to establish the natural biosynthetic pathway to (+) pisatin, and
Dirigent isoflavene-forming PsPTS2: 3D structure, stereochemical, and kinetic characterization comparison with pterocarpan-forming PsPTS1 homolog in pea
作者:Qingyan Meng、Syed G.A. Moinuddin、Rhodesia M. Celoy、Clyde A. Smith、Robert P. Young、Michael A. Costa、Rachel A. Freeman、Masashi Fukaya、Doo Nam Kim、John R. Cort、Martha C. Hawes、Hans D. van Etten、Pankaj Pandey、Amar G. Chittiboyina、Daneel Ferreira、Laurence B. Davin、Norman G. Lewis
DOI:10.1016/j.jbc.2024.105647
日期:2024.3
were determined using NMR spectroscopy, electroniccirculardichroism, and molecular orbital analyses. PsPTS2 efficiently converted -(3,4)-DMDI into DMDIF 20-fold faster than the -(3,4)-isomer. The 4-configured substrate’s near β-axial OH orientation significantly enhanced its leaving group abilities in generating A-ring mono-quinone methide (QM), whereas 4-isomer’s α-equatorial-OH was a poorer leaving