Pterocarpadiols A-D, Rare 6a,11b-Dihydroxypterocarpans from Derris robusta

Derrisrobustones A-D, isoflavones from the twig extract of Derris robusta (DC.) Benth. and their α-glucosidase inhibitory activity

Three previously undescribed isoflavones, derrisrobustones A-C, and a previously undescribed natural isoflavone, derrisrobustone D, along with eight known isoflavones, were isolated from the twig extract of Derris robusta (DC.) Benth. All structures were identified by extensive spectroscopic analysis. Derrisrobustones A-C were obtained as scalemic mixtures and were resolved by chiral HPLC. The (1″R, 2″R) absolute configuration of (+)-derrisrobustone B was established by single-crystal X-ray crystallography using Cu Kα radiation. The absolute configurations of derrisrobustones A and C were determined by analysis of experimental and calculated ECD data. All compounds were evaluated for their α-glucosidase inhibitory activity. Of these, derrubone displayed the best α-glucosidase inhibitory activity with an IC₅₀ value of 64.2 μM.

A Novel Pterocarpan Derivative From the Roots of Sophora flavescens

Flavescensin A (1), a novel rearrangement derivative of pterocarpan with an unusual spirotetrahydrofuran ring, along with 7 known pterocarpans were isolated from the roots of Sophora flavescens using several different chromatographic separations. The planar structure of 1 was elucidated by their nuclear magnetic resonance spectroscopic and high-resolution electrospray ionization mass spectrometry data, and the absolute configuration of 1 was determined on the basis of electronic circular dichroism data. Putative biosynthetic pathway toward 1 was proposed. In addition, all of the compounds were evaluated for their anti-influenza virus and anti-inflammatory activities.

Isolation of naturally occurring novel isoflavonoids: an update

This review covers the literature concerning the isolation and identification of new naturally occurring isoflavonoids from Leguminosae and non-Leguminous species between 2012–2017.

Derrisisoflavones H-K and One Isoflavan Derivative from Derris robusta

Four hitherto unknown prenylated isoflavonoids, named derrisisoflavones H-K (1-4) and one new isoflavan, namely 6-hydroxyisosativan (5), were isolated from the ethanol extract of Derris robusta. Their structures were elucidated on the basis of extensive spectroscopic studies. To our knowledge, derrisisoflavones J (3) and K (4) are the first examples of hydroxyethylated isoflavonoid.