2035-15-6Relevant articles and documents
(+)-Pisatin biosynthesis: From (-) enantiomeric intermediates via an achiral 7,2′-dihydroxy-4′,5′-methylenedioxyisoflav-3-ene
Celoy, Rhodesia M.,VanEtten, Hans D.
, p. 120 - 127 (2014)
(+)-Pisatin, produced by peas (Pisum sativum L.), is an isoflavonoid derivative belonging to the pterocarpan family. It was the first chemically identified phytoalexin, and subsequent research has demonstrated that most legumes produce pterocarpans with the opposite stereochemistry. Studies on the biosynthesis of (+)-pisatin have shown that (-) enantiomeric compounds are intermediates in (+)-pisatin synthesis. However, the steps from the (-)-7,2′-dihydroxy-4′,5′-methylenedioxyisoflavanone [(-)-sophorol] intermediate to (+)-6a-hydroxymaackiain intermediate are undetermined. Chemical reduction of (-)-sophorol using sodium borohydride (NaBH4) produced two isomers of (-)-7,2′-dihydroxy-4′, 5′-methylenedioxyisoflavanol [(-)-DMDI] with optimal UV absorbance at 299.3 and 300.5 nm, respectively. In contrast, enzymatic reduction of (-)-sophorol by the pea enzyme sophorol reductase (SOR) produced only the 299.3 nm (-)-DMDI isomer. Proton nuclear magnetic resonance (1H NMR) analysis of the 299.3 nm (-)-DMDI isomer demonstrated that this isomer had the same NMR spectrum as previously reported for cis-isoflavanol isomers, indicating that cis-(-)-DMDI is an intermediate in (+)-pisatin biosynthesis. Enzyme assays using protein extracts from pea tissue treated with CuCl2 as an elicitor converted the cis-(-)-DMDI isomer into an achiral isoflavene, 7,2′-dihydroxy-4′,5′-methylenedioxyisoflav-3-ene (DMDIF), and the trans-(-)-DMDI isomer was not metabolized by the same protein preparation. A comparison of the enzyme activities on cis-(-)-DMDI with protein preparations from elicited tissue versus non-elicited tissue showed a threefold increase in the amount of activity in the proteins from the elicited tissue. Proteins from the elicited tissues of alfalfa, bean, and chickpea converted cis-(-)-DMDI into either (-)-maackiain and/or (-)-sophorol, while proteins from the elicited tissues of broccoli and pepper produced no detectable product. These results are consistent with the involvement of cis-(-)-DMDI and the achiral DMDIF as intermediates in (+)-pisatin biosynthesis.
(±)-3,4-Dihydroxy-8,9-methylenedioxypterocarpan and derivatives: Cytotoxic effect on human leukemia cell lines
Netto, Chaquip D.,Santos, Eduardo S.J.,Castro, Carolina Pereira,da Silva, Alcides J.M.,Rumjanek, Vivian M.,Costa, Paulo R.R.
body text, p. 920 - 925 (2009/09/08)
Naturally occurring pterocarpans 1a,b, pterocarpan 1c, isoflavane 2 and ortho-quinone 3 were synthesized in the racemic form and their cytotoxic effect was evaluated on the human leukemia cell lines K562 (resistant to oxidative stress), Lucena-1 (MDR phenotype) and HL-60. Ortho-quinone 3 (IC50 = 1.5 μM, 1.8 μM and 0.2 μM, respectively) and catechol pterocarpan 1a (IC50 = 3.0 μM, 3.7 μM and 2.1 μM, respectively) were the most active compounds on these cells and were also evaluated on other human leukemia cell lines (Jurkat and Daudi). Ortho-quinone 3 was 2 to 10 times more potent than pterocarpan 1a, depending on the cell line considered, however, showed a greater toxicity for lymphocytes activated by PHA.
Absolute configuration and total synthesis of (-)-cabenegrin A-I
Tokes, Adrienne L.,Litkei, Gyoergy,Gulacsi, Katalin,Antus, Sandor,Baitz-Gacs, Eszter,Szantay, Csaba,Darko, Laszlo L.
, p. 9283 - 9296 (2007/10/03)
The total synthesis of (-)-cabenegrin A-I [(-)-1] in five steps was achieved from (-)-6aR, 11aR-maackiain [(-)-5], which in turn was prepared by the optical resolution of racemic (±)-5 using S-(-)α-methylbenzyl isocyanate as the the chiral auxiliary. The homochirality of(-)-maackiain [(- )-5] and (-)cabenegrin A-I [(-)-1] was proved by CD measurements. Synthesis of (±)maackiain [(±)-5] is also presented, starting from the readily available phenol derivatives resorcinol and sesamol, which demonstrates the synthetic utility of the Heck-type oxyarylation process for obtaining pterocarpane derivatives on a multigram scale. A new ring-opening reaction of pterocarpanes (7 → 28) is described.
