Isoflavan derivatives

Kinoshita, T. et al., Isoflavan derivatives from Glycyrrhiza glabra (licorice). Heterocycles, 43, 581, 1996. 

Dr. SfflBATA has informed us that he could not exclude the possibility of Shosoin licorice to be G. uralensis by the HPLC analysis and further chemical examination of the drug is now progress in 2nd research of Shosoin materials, t The stereochemistry of isoflavan derivatives mentioned in this section is described in Section 4. 

Ahmed, M., Khaleduzzaman, M., and Islam, M.S., Isoflavan-4-ol, dihydrochalcone and chal-cone derivatives from Polygonum lapathifolium, Phytochemistry, 29, 2009, 1990. 

Kent UM, Aviram M, Rosenblat M, et al. The licorice root derived isoflavan glabridin inhibits the activities of human cytochrome P450S 3A4, 2B6, and 2C9. Drug Metah Dispos 2002 30(6) 709-715. 

Almost half of the isoflavonoids identified from the Leguminosae, in which prenylated isoflavones constitute >50% of the total (pterocarpanoids, rotenoids, isoflavanones, isoflavans, coumestans, 3-arylcoumarins, and coumaronochromones), exhibit a high degree of structural diversity and complexity of prenylation.8,86"148 More than half of the isoflavones are monoprenylated, whereas 40% are diprenylated, and very few are triprenyl derivatives, with prenylation at positions 6>8>3 5 >6,>2 and O-methylation at 4 >7=6=2 =3 >5 =5>8. A number of novel isoflavonoid structures with rare skeletons, as well as complex isoflavone O- and C-glycosides have recently been reported.8,148... 

In this category we include phenolic compounds based on the structure of 2-phenyl-4H-l-benzopyran-4-one (flavones, flavonols and related dihydro analogues), the isomeric 3-phenyl derivatives (isoflavonoids, including isoflavans) and other non-pyronic C6-C3-C6 plant pigments such as chalcones, aurones and anthocyanidins. 

The absolute configuration of the compounds could not be determined by CD spectra. The other compounds were assigned as R-isoflavan by their CD spectrum or chemical correlation (a) derived from glabridin (126) with the prenylation reaction b) derived from licoricidin (165) according to the previous literature (267) (c) derived from licoricidin (164) with Friedel-Crafts reaction (unpublished data)... 

Dalbergin derivs Cinnamylphenols Dihydro Isoflavones Pterocarpans benzofurans Isoflavans... 

Less common compounds with ring B associated with pyran ring C in position C-3 (derived from isoflavan) are called isoflavonoids (also known as 3-phenylchromen-4-ones or 1,2-diarylpropanes, 9-76). If the connection between these two rings is in position C-4, the corresponding compounds, derived from neoflavan, are called neoflavonoids or 4-phenylcoumarins, 5,6-benzo-2-pyrones or 1,1-diarylpropanes (9-77). 

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