Prenylated Flavonoids from the Root of Egyptian Tephrosia apollinea – Crystal Structure Analysis

Abstract

Three complex 7-oxygenated-8-prenylflavones, (-)-semiglabrin and (-)-pseudosemiglabrin, which are diastereoisomers, and lanceolatin A have been isolated from the root of Tephrosia apollinea (Del.) Link (Leguminosae) growing in Southern Egypt, together with two phytosterols, stigmasterol and sitosterol. The structures of the isolated compounds have been elucidated by means of physical and several spectroscopic methods including UV, IR, 1 H, 13 C NMR, DEPT, 2D 1 H-1 H COSY, HSQC, HMBC experiments, and high resolution mass spectrometry (HR-MS), as well as some chemical transformations. The stereochemistry of the structures of (-)-semiglabrin and lanceolatin A have been confirmed by X-ray crystal structure analysis. The anticarcinogenic properties of the isolated compounds showed no inhibitory mechanisms concerning the initiation, promotion, and progression stage of carcinogenesis. Moreover, the in vitro antimicrobial activities of the root ethanolic extract are discussed.

Correlation of antiangiogenic, antioxidant and cytotoxic activities of some Sudanese medicinal plants with phenolic and flavonoid contents

“…It is well known that the plant-flavonoids demonstrated promising anticancer and antiangiogenic activities [ 55 ]. Several studies [ 56 ] reported the presence of complex prenylated flavones and phenolic compounds in T. apollinea and thus the antiangiogenic and antiproliferative properties of the herb recorded in the present study can be attributed to the cumulative effects of such bioactive constituents.…”

Terpurinflavone: An antiplasmodial flavone from the stem of Tephrosia Purpurea

“…The organic layer (36 g) was subjected to CC on silica gel (400 g) eluting with n-hexane containing increasing percentages (2%, 4%, 6%, 8%, 10%, 12.5%, 15%, 17.5%, 20%, 25%, 30%, 40%, 50%, 75% and 100%) of ethyl acetate and gave 15 fractions each of 1.5 L. The fraction eluted with 6% ethyl acetate in n-hexane was crystallized from n-hexane-dichloromethane mixture to yield lanceolatin B (4, 317 mg) (Pelter et al, 1981). The fractions eluted with 10% and 12.5% ethyl acetate in n-hexane were mixed and further purified by CC on Sephadex LH-20 (CH 2 Cl 2 -MeOH; 1:1) and crystallization from acetone gave semiglabrin (3, 87 mg) (Waterman and Khalid, 1980;Abou-Douh et al, 2005;Pelter et al, 1981). The fraction eluted with 15% ethyl acetate was separated on Sephadex LH-20 (CH 2 Cl 2 -MeOH; 1:1) to give terpurinflavone (1, 34 mg).…”

“…Tephrosia Pers (Leguminosae-Papilionoideae) is a large tropical and sub-tropical genus estimated to contain about three hundred species (Waterman and Khalid, 1980;Abou-Douh et al, 2005) out of which thirty species are found in Kenya (Tarus et al, 2002). The extracts of some Tephrosia species have shown various biological activities including antiplasmodial (Muiva et al, 2009), antibacterial (Abou-Douh et al, 2005) anticancer (Santram et al, 2006) and insecticidal activities (Delfel et al, 1970).…”

“…The extracts of some Tephrosia species have shown various biological activities including antiplasmodial (Muiva et al, 2009), antibacterial (Abou-Douh et al, 2005) anticancer (Santram et al, 2006) and insecticidal activities (Delfel et al, 1970). The taxon T. purpurea is among the most widely used Tephrosia species in traditional medicine (Damre et al, 2003).…”

Medicinally active principles analysis of Tephrosia apollinea (Delile) DC. growing in the United Arab Emirates

“…Tephrosia purpurea extracts showed the presence of isoflavones, flavanones, flavanols and flavones [13]. The leaves of Tephrosia contains semiglabrin, semigalbrinol, and a flavanone named apollineanin [14].…”