Flavonoids Isolated from Heat‐Processed Epimedium koreanum and Their Anti‐HIV‐1 Activities

Abstract

Systematic phytochemical investigation on heat-processed Epimedium koreanum led to the isolation of 13 flavonoids, including five new prenyl-flavonol glycosides,k oreanosidesA-E (1 -5,r esp.).T heir structures were elucidated on the basis of detailed analysis of the 1D-and 2D-NMR spectroscopic data and chemical reactions.A pigenin (11)e xhibited moderate anti-HIV-1 activity with an EC 50 value of 12.8 AE 3.27 mg/ml.Introduction. -Herba epimedii, also named Horny Goat Weed or YinY ang Huo, has been used in Tr aditional Chinese Medicine (TCM)a sat onic, antirheumatic, and aphrodisiac for more than 2000y ears.T he aerialp arts of Epimediumk oreanum (Berberidaceae), togetherwith threeother species, E. brevicornu, E. sagittatum,and E. pubescens,w ere officially adopted in the Chinese Pharmacopoeia [1].P revious chemical and pharmacological investigations on epimedii foundt hat the major bioactivec onstituents are prenyl-flavonoids,w hich exhibit aw ide range of biological activities,s ucha sa nti-osteoporosis,a ndrogenic, anti-inflammatory,a nd anticancer effects [2]. EpimedinC ,i cariin, and baohuoside I, threem ain flavonoids in the crude herb,h ave been used as markers for quality evaluationb yHPLC/UV[ 1] [3].Traditionally,h erba epimedii was processed by heating with sheepf at to enhance hormonal and anti-inflammatory effects [4][5].R eportedly,H PLC analysis showed that the content of prenyl-flavonoid bisdesmosides (such as icarrin and, epimedins A-C) decreased in the heat-processed form, whereas that of monodesmosides (such as baohuoside I) increased [6]. In an in vitro cultured Caco-2 cell model, the absorption and metabolism of the monoglycosideb aohuosideIwas greatert han those of bisdesmoside prenyl-flavonoidsw ith two or more sugar moieties [7].However, no systematic phytochemical study on heat-processed epimedii has been reported.A sacontinuation of our research on medicinal plantsi nt he genus Epimedium [8][9], 13 flavonoids,i ncludingf ive new prenyl-flavonol glycosides, koreanosides A-E( 1 -5,r esp.; Fig. 1), were isolated from heat-processed E.

Prenylated Flavonoid Glycosides with PCSK9 mRNA Expression Inhibitory Activity from the Aerial Parts of Epimedium koreanum

“…The known compounds 5-22 (Figure 1) were confirmed by NMR and MS as koreanoside E (5) [21], icariside I (6) [22], ikarisoside A (7) [23], icariside II (8) [24], epime-doside A (9) [6,25], icariin (10) [26], epimedin A (11) [3], korepimedoside C (12) [27], epimedin B (13) [3], epimedin C ( 14) [3], anhydroicaritin 3-O-β-D-fucopyranosyl(1→2)-α-Lrhamnopyranoside-7-O-β-D-glucopyranoside (15) [28], icarisid I ( 16) [29], korepimedoside A (17) [30], epimedokoreanoside I (18) [6], korepimeoside C (19) [31], epimedin L (20) [5], caohuoside B (21) [32], and epimedoicarisoside A ( 22) [33]. Compound 1 was obtained as a yellow amorphous powder and its molecular formula was determined to be C 35 1), a singlet proton signal at δ H 6.65 (1H, s, H-6), two doublet signals at δ H 7.85 (2H, d, J = 8.8 Hz, H-2 and H-6 ) and 7.10 (2H, d, J = 8.8 Hz, H-3 and H-5 ) corresponding to a flavonol skeleton, and the signals responsible for an isoprenyl unit at δ H 3.52 (1H, m, H-11a), 3.57 (1H, m, H-11b), 5.19 (1H, t, J = 6.8 Hz, H-12), 1.64 (3H, s, H-14), and 1.73 (3H, s, H-15) were observed.…”

Effectiveness of Prenyl Group on Flavonoids from Epimedium koreanum Nakai on Bacterial Neuraminidase Inhibition

“…Similarly, subfractions B17–21 (1.1 g), enriched with compounds 1 – 3 , were used in the recycle HPLC to yield compounds 1 (11 mg), 2 (16 mg), and 3 (8 mg). All the isolated compounds were identified on the basis of spectroscopic data and comparisons with previous studies (Supplementary Materials) [15,19,20].…”

Prenylated Flavonoids of Genus Epimedium: Phytochemistry, Estimation and Synthesis

“…Pang et al reported another set of three new prenylated flavonoids: epicornunin A ( 25 ), epicornunin B ( 26 ) and epicornunin F ( 27 ) from E. brevicornum Maxim [37] . Phytochemical investigation on E. koreanum lead to the isolation of five more new prenylated flavonol glycosides, korepimeoside A ( 28 ), B ( 29 ), C ( 30 ), D ( 31 ) & E ( 32 ) [38] . In another report two new isoprenoid acylated flavonol glycosides: elatoside A ( 33 ) and elatoside B ( 34 ) have been isolated from E. elatum (Figure 3).…”

“…[37] Phytochemical investigation on E. koreanum lead to the isolation of five more new prenylated flavonol glycosides, korepimeoside A (28), B (29), C (30), D ( 31) & E (32). [38] In another report two new isoprenoid acylated flavonol glycosides: elatoside A (33) and elatoside B (34) have been isolated from E. elatum (Figure 3). [16c] Two new prenylated flavonol glycosides, epimedigrandioside A (35) and B (36) and other known prenylated flavonols have been reported from Epimedium grandiflorum.…”