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.

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.

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

Four hitherto unknown 6a,11b-dihydroxypterocarpans, namely pterocarpadiols A-D (1-4), were isolated from the ethanol extract of the twigs and leaves of Derris robusta. Their structures were elucidated on the basis of extensive spectroscopic analysis. Pterocarpadiols A-D are a kind of very rare 6a,11b-dihydroxypterocarpans, and their presence as markers may be helpful in chemotaxonomical classification.