Conrauinones A and B, Two New Isoflavones from Stem Bark of Millettia conraui

Abstract

Two new isoflavones, named conrauinones A (1) and B (2), have been isolated from the stem bark of Millettia conraui, in addition to known 5-methoxydurmillone. The structures of the new compounds were determined by spectroscopic analysis including 2D NMR techniques as 5,6,2'-trimethoxy-4',5'-(methylenedioxy)-2",2"-dimethylpyrano[5",6":7,8]isoflavone (1) and 6-methoxy-3',4'-(methylenedioxy)-7-O-[(E)-3",7"-dimethyl-7"-ol-2",5"-octadienyl]isoflavone (2).

Isoflavonoids of the Leguminosae

“…76 In bioassays, only brandisianin D (31) showed enhancement of DR5 promoter activity when compared to luteolin as positive control. 77 This species is already known as the source of the O-geranylated isoflavones, conrauinones B-D. 78 85 The furanoisoflavone isoelliptol (44) was first synthesised in 1965, 86 and several known isoflavonoids, 88 including one with spectroscopic data similar to those reported for fremontin (46a) from the related species Psorothamnus fremontii. 77 This species is already known as the source of the O-geranylated isoflavones, conrauinones B-D. 78 85 The furanoisoflavone isoelliptol (44) was first synthesised in 1965, 86 and several known isoflavonoids, 88 including one with spectroscopic data similar to those reported for fremontin (46a) from the related species Psorothamnus fremontii.…”

“…76 A 7-O-geranyl derivative (33) of fujikinetin (7-hydroxy-6-methoxy-3 0 ,4 0 -methylenedioxyisoflavone) isolated from stem bark of Millettia conraui showed a-glucosidase inhibitory activity in vitro (IC 50 35.5 AE 0.5 mM) better than that of deoxynojirimycin (IC 50 425 AE 8.14 mM) and acarbose (IC 50 780 AE 28 mM). 77 This species is already known as the source of the O-geranylated isoflavones, conrauinones B-D. 78,79 Four further prenylated isoflavones (34-37) from Millettia griffoniana were described in two papers by Ngamba et al, 80,81 comprising 7-O-methylebenosin (34), and griffonianones E (35), F (36) and H (37), all of which were isolated from the seeds. Moderate trypanocidal and antiplasmodial activity was demonstrated for griffonianone E (35).…”

An ultrasound assisted cyclocondensation reaction for the efficient synthesis of [1]benzopyranopyrido[d]pyrimidines using porous graphene/MoO3

“…[ 36 ] Moreover, the core structure of fused [1]benzopyran is widespread in a large number of well ‐ known medicinally relevant natural compounds. For example, uvafzlelin, as a naturally occurring 4 H ‐[1]benzopyran isolated from the stems of Uvaria ufielii , has been identified as antimicrobial against Gram‐positive and acid‐fast bacteria, [ 37 ] conrauinone A has been isolated from the bark of the tree Millettia conraui and shown potential ability in the treatment of intestinal parasites, [ 38 ] and erysenegalensein C extracted from the bark of Erythrina senegalensis can be used as a drug for the treatment of stomach pain, female infertility, and gonorrhea [ 39 ] (Figure 1).…”

Immobilized TiO2nanoparticles on carbon nanotubes: an efficient heterogeneous catalyst for the synthesis of chromeno[b]pyridine derivatives under ultrasonic irradiation

“… 13 Moreover, compounds incorporating chromene core structures are most prevalent among natural bio-active compounds. For example uvafzlelin, as a naturally occurring 4 H -chromene isolated from the stems of Uvaria ufielii , can be regarded as antimicrobial against Gram-positive and acid-fast bacteria, 14 conrauinone A extracted from the bark of the tree Millettia conraui is useful in the treatment of intestinal parasites, 15 and erysenegalensein C has been isolated from the bark of Erythrina senegalensis and is recognized as a drug for the treatment of stomach pain, female infertility and gonorrhoea ( Fig. 1 ).…”