FlavoneC-glycosides from the Leaves ofLophatherum gracileand TheirIn VitroAntiviral Activity

Abstract

Four new flavone C-glycosides, luteolin 6-C-α-L-arabinopyranosyl-7-O-β-D-glucopyranoside, apigenin 6-C-β-D-galactopyranosiduronic acid (1 → 2)-α-L-arabinopyranoside, luteolin 6-C-β-D-galactopyranosiduronic acid (1 → 2)-α-L-arabinopyranoside, and luteolin 6-C-β-D-glucopyranosiduronic acid (1 → 2)-α-L-arabinofuranoside, along with three known ones, were isolated from the leaves of Lophatherum gracile. The structures of the new compounds were elucidated by extensive spectroscopic methods as well as acid hydrolysis. All the flavone glycosides isolated from this plant were screened for their in vitro antiviral activity against respiratory syncytial virus (RSV) with cytopathic effect (CPE) reduction assay, and several flavone 6-C-monoglycosides showed potent in vitro anti-RSV effect.

Application of High-Speed Counter-Current Chromatography Preparative Separation of FlavoneC-Glycosides FromLophatherum gracile

“…The 13 C NMR and DEPT spectra of compound 1 displayed 27 carbon signals due to one flavone aglycone and two sugar moieties. The proton and carbon signals corresponding to the aglycone part of compound 1 were in good agreement with those of luteolin (4,5). The two sugar units in compound 1 were identified as b-D-galactopyrano-siduronic acid and b-D-glucopyranose, respectively, by comparison with the NMR data with those reported in the literatures (5,13).…”

“…The proton and carbon signals corresponding to the aglycone part of compound 1 were in good agreement with those of luteolin (4,5). The two sugar units in compound 1 were identified as b-D-galactopyrano-siduronic acid and b-D-glucopyranose, respectively, by comparison with the NMR data with those reported in the literatures (5,13). In the ROESY spectrum of compound 1, correlation between H-1 000 (d H 4.16) of the galacturonic acid and H-1 00 (d H 4.64) of the glucose indicated that the galacturonic acid was attached to the C-2 00 of glucose.…”

“…Similar to compound 1, the 13 C NMR and DEPT spectra of compound 6 also displayed 27 carbon signals due to one flavone aglycone and two sugar moieties. Different from compound 1, the NMR data of compound 6 assigned to the aglycone part were very similar to those of apigenin (4,5). A comparison of the NMR data of the sugar units in compound 6 with those of 1 showed that they were very similar, indicating that compound 6 possessed the identical sugar chain to 1.…”

“…The major and effective components of this herb were reported as flavones (3,4). Several flavone C-glycosides from this herb showed potent in vitro antiviral activity against respiratory syncytial virus (RSV) (5). Because of their structural similarity, the large scale-up of separation and purification of them are a tough job but indispensable to study in vivo activities.…”

Ethanol extract of Lophatheri Herba exhibits anti-cancer activity in human cancer cells by suppression of metastatic and angiogenic potential

“…Polysaccharides purified from LH possess strong anti-oxidant capabilities28, and oral administration of LH flavonoids exerts a protective effect on restraint stress-induced liver injury in mice29. In addition, flavone C-glycosides isolated from LH show potent anti-viral activity against human respiratory syncytial virus (RSV)30.…”