Zi-Ming Feng

Two New Quinochalcones from the Florets of Carthamus tinctorius

Two new quinochalcone compounds, named saffloquinoside A (1) and saffloquinoside B (2), were isolated from the florets of Carthamus tinctorius. Their unusual structures including their absolute stereochemistry were elucidated based on UV, IR, HRESIMS, 1D and 2D NMR data, and CD spectrum. Saffloquinoside A has an uncommon six-five member dioxaspirocycle and saffloquinoside B has a cyclohexatrione skeleton with a benzyl group and two C-glycosyl units. Saffloquinoside A exhibited middling anti-inflammatory activity.

NMR Solution Structure Study of the Representative Component Hydroxysafflor Yellow A and Other Quinochalcone C-Glycosides from Carthamus tinctorius

Hydroxysafflor yellow A (HSYA), a representative component of Carthamus tinctorius, has attracted much attention because of its remarkable cardiovascular activities. Its structure was originally reported in 1993 and has been widely cited to date. In our experiments, its solution structure was studied using NMR techniques in different solvents, including DMSO-d(6), pyridine-d(5), and CD(3)OH. The results indicate that the structure of HSYA is different than the previously described 1b, with 3-enol-1,7-diketo form. The structure has two keto-enol tautomers (2a and 2b), and 2a, with the 1-enol-3,7-diketo form, is the preferred tautomer. On the basis of this finding, other published quinochalcone C-glycoside structures were revised. Furthermore, a trend in the (13)C NMR data of the (E)-olefinic carbons of quinochalcone C-glycosides is summarized, and a hypothesis is proposed for the relationship between the features of the molecular structure and the preferred keto-enol tautomer.

Hepatoprotective glycosides from Leonurus japonicus Houtt.

Two new phenylethanoid glycosides 1 and 2 named leonoside E and leonoside F, and one new sesquiterpene glycoside (3) identified as 7α (H)-eudesmane-4,11 (12)-diene-3-one-2β-hydroxy-13-β-d-glucopyranoside, together with seven known glycosides (4-10), were isolated from the aerial part of Leonurus japonicus Houtt. Their structures were elucidated on the basis of spectroscopic data and chemical evidence. When tested in in vitro assays, compounds 1, 2, 4, and 6 exhibited potent hepatoprotective activity against d-galactosamine-induced toxicity in HL-7702 cells at concentration of 1×10(-5) M.

New polyacetylene glucosides from the florets of Carthamus tinctorius and their weak anti-inflammatory activities

Eight new linear polyacetylene glucosides (1-8), containing two C(10)-, one C(13)- and five C(14)-acetylenes, together with three known polyacetylenes (9-11) were isolated from the florets of Carthamus tinctorius L. Their structures were elucidated by means of spectroscopic methods and chemical evidence. The absolute configurations of compounds 3-9 were confirmed by Snatzke and Gerardss method, observing the induced circular dichroism after addition of dirhodium tetrakis (trifluoroacetate) [Rh(2)(OCOCF(3))(4)] in CHCl(3). All the isolated compounds (1-11) were also tested for inhibitory activities against LPS-induced NO production in murine macrophages and just showed weak activities at concentrations of 1×10(-5)M.

Hepatoprotective constituents from the roots and stems of Erycibe hainanesis.

Eleven new diglycosides, erycibosides A-K (1-11), four new chlorogenic acid derivatives (14-17), and a new bis-coumarin (18), together with 21 known compounds, have been isolated from an EtOH extract of the roots and stems of Erycibe hainanesis. Their structures were elucidated by means of spectroscopic methods and chemical evidence. Inhibitory activities of some of the compounds on d-galactosamine-induced cytotoxicity in WB-F344 rat hepatic epithelial stem-like cells were screened, and compounds 2, 6, 10, 18, and 32 showed potent hepatoprotective activities at concentrations of 1 x 10(-5) to 1 x 10(-4) M.

Dibenzoyl and Isoflavonoid Glycosides from Sophora flavescens: Inhibition of the Cytotoxic Effect of d-Galactosamine on Human Hepatocyte HL-7702

Twelve new dibenzoyl derivatives sophodibenzoside A-L (1-12) and five new isoflavone glycosides (13-17) have been isolated from the roots of Sophora flavescens together with eight known compounds (18-25). Notably, the use of acetic acid-d4 was required to enable identification of the dibenzoyl glycoside structures. Compounds 1, 2, 13, 14, and 19 exhibited weak inhibition of the cytotoxic effect of d-galactosamine on the human hepatic cell line HL-7702.

Acyl glycosides with rare β-d-apiofuranosyl-β-d-glucopyranosyl-β-d-apiofuranosyl from Erycibe hainanesis

Three new acyl glycosides with rare β-D-apiofuranosyl-(1→2)-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranosyl moieties, 2-O-[2,6-O-bis(5-O-syringoyl-β-D-apiofuranosyl)-β-D-glucopyranosyl]-isopropyl alcohol (1), 1-O-[2,6-O-bis(5-O-syringoyl-β-D-apiofuranosyl)-β-D-glucopyranosyl]-isoamyl alcohol (2), and 1-O-[2,6-O-bis(5-O-vanilloyl-β-D-apiofuranosyl)-β-D-glucopyranosyl]-3,4,5-trimethoxyphenol (3) were obtained from Erycibe hainanesis. Their structures were determined by UV, IR, HRESIMS, (1)D and (2)D NMR data, and by chemical methods. Compounds 1-3 were evaluated against D-galactosamine induced toxicity in WB-F344 rat hepatic epithelial stem-like cells, and compounds 1 and 3 showed moderate hepatoprotective activities.

Bioactive Sesquiterpenoid and Polyacetylene Glycosides from Atractylodes lancea.

Nine new sesquiterpenoids (1-9), five new polyacetylenes (10-14), and six known compounds were isolated from the rhizomes of Atractylodes lancea. These new chemical structures were established using NMR, MS, and ECD data. Notably, compounds 3-5, the aglycone of which possesses two stereogenic centers (C-5 and C-7), exhibited similar ECD spectra to compounds 1 and 2, the aglycone of which possesses one stereogenic center (C-7). Such a difference was supported by the experimental and calculated ECD data and single-crystallographic analyses of 3a. In addition, compound 3 inhibited lipopolysaccharide-induced NO production in BV2 cells with an IC50 value of 11.39 μM (positive control curcumin, IC50 = 4.77 μM); compound 4 showed better hepatoprotective activity against N-acetyl-p-aminophenol-induced HepG2 cell injury than the positive drug (bicyclol) at a concentration of 10 μM (p < 0.001).

Polyflavanostilbene A, a New Flavanol-Fused Stilbene Glycoside from Polygonum cuspidatum

Polyflavanostilbene A, a new flavanol-fused stilbene glycoside, was isolated from the rhizome of Polygonum cuspidatum. Its unusual structure, including its absolute stereochemistry, was determined by UV, IR, HRESIMS, and 1D and 2D NMR data and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Polyflavanostilbene A has an unprecedented rearranged flavanol skeleton fused to stilbene via a hexahydrocyclopenta[c]furan moiety. Polyflavanostilbene A showed strong inhibitory activity against α-glucosidase with an IC(50) value of 17.7 μM.

New Hepatoprotective Coumarinolignoids from Mallotus apelta

Three new coumarinolignoids, malloapelins A–C (1–3, resp.), together with three known coumarinolignoids, cleomiscosin A (4), cleomiscosin B (5), and 5′‐demethylaquillochin (6), were isolated from the roots of Mallotus apelta Muell.‐Arg. Compounds 1–6 are three pairs of regioisomeric coumarinolignoids. Their structures were elucidated on the basis of spectral evidence. Compounds 3 showed promising hepatoprotective activity against D‐galactosamine‐induced toxicity in WB‐F344 rat hepatic epithelial stem‐like cells.