Qi Ye

Dihydroagarofuran Derivatives from the Dried Roots of Tripterygium wilfordii

Five new sesquiterpene derivatives, including dihydroagarofuran pyridine macrolides 1-4 and dihydroagarofuran ester 18, and 13 known dihydroagarofuran derivatives were isolated from the aqueous EtOH extract of the dried roots of Tripterygium wilfordii. An in vitro antiherpetic activity assay indicated that compounds 11 and 17 displayed weak and moderate inhibition against herpes simplex virus type II, respectively.

Nitrogen-Containing Dihydro-β-agarofuran Derivatives from Tripterygium wilfordii

Thunder god vine, the dried roots of Tripterygium wilfordii, is a widely used traditional Chinese medicine. More than 200 bioactive complex natural products have been isolated from this herb. Inspired by the diversity of chemical structures and bioactivities of the components of this herb, the investigation to mine new chemical entities as potential drug leads led to the identification of 36 nitrogen-containing compounds. Among them, 18 new dihydro-β-agarofuran alkaloids (tripterygiumines A-L (1-12), M-Q (22-26), and R (33)) were identified from the spectroscopic data and chemical degradation studies. Tripterygiumine Q (26) exhibited immunosuppressive activity against human peripheral mononuclear cells with an IC50 value of 8.67 μM and showed no cytotoxicity, even at 100 μM, indicating that 26 may represent a novel scaffold for the development of new immunosuppressants.

A novel alkaloid from Mitrephora maingayi

A novel alkaloid, maingayinine, together with dicentrinone, dicentrinene, L-2-O-methyl-chiro-inositol, allantoin, glaucine, N-phenyl-2-naphthylamine, terephthalic acid and ayanin, was isolated from the twigs of Mitrephora maingayi Hook (Annonaceae). Their structures were established predominantly by IR, MS and NMR spectral data.

A new anthraquinone from Gladiolus gandavensis.

A new anthraquinone, 1,6,7-trihydroxy-3-methoxyanthraquinone, along with three known compounds methyl trans-p-hydroxycinnamate, eugenin and 1,3,6-trihydroxy-8-methylanthraquinone, were isolated from the subterranean rhizomes of Gladiolus gandavensis Van Houtt. Their structures were established on the basis of spectroscopic data including 2D NMR techniques and chemical methods.

Iridoid Glucosides and Diterpenoids from Caryopteris glutinosa

Five new iridoid glucoside derivatives (1-5), three new diterpenoids (7, 12, and 15), and 11 known compounds were isolated from the aqueous EtOH extract of Caryopteris glutinosa. Cell-based estrogen biosynthesis assays indicated that caryopteriside C (3) and caryopterisoid B (12) promote the biosynthesis of estrogen E2, with EC50 values of 11.1 and 8.0 μM, respectively, in human ovarian granulosa-like KGN cells via upregulating the expression of aromatase.

Novel 2-arylbenzofuran dimers and polyisoprenylated flavanones from Sophora tonkinensis.

Two novel 2-arylbenzofuran dimers, shandougenines A (1) and B (2), and two new polyisoprenylated flavanones 3 (shandougenine C) and 4 (shandougenine D) were isolated from the 95% EtOH extract of Sophora tonkinensis, together with 18 known compounds. Their structures were determined on the basis of spectral data interpretation and by comparing the spectral data with that reported previously for known compounds. Shandougenine A (1) is a unique dimeric 2-arylbenzofuran with a C-3C-5‴ bond linkage. Shandougenine B (2) is the first naturally occurring dimeric 2-arylbenzofuran with a novel C-3C-3″ bond linkage. Compound 1 showed moderate DPPH free radical scavenging capacity, whereas 2 has stronger DPPH free radical and ABTS cation radical scavenging capacity than Vc. Compounds 12, 19, and 20 showed parallel DPPH free radical scavenging capacity with Vc. Compounds 1, 3, 4, 19, 20, and 22 have parallel ABTS cation radical scavenging capacity to Vc. Compounds 1, 3, 4, and 18 showed slightly stronger superoxide anion radical scavenging capacity than the known flavanone luteolin. The antioxidant activities of shandougenines A (1) and B (2) indicated that compounds 1 and 2 may represent novel scaffolds for the development of new antioxidants.

Anthraquinones from Gladiolus gandavensis

Five new anthraquinones have been obtained from the ethanolic extracts of the subterranean corms of Gladiolus gandavensis Van Houtt. Their structures were elucidated as 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone (gandavensin D, 1), methyl 3,8-dihydroxy-6,7-methylenedioxy-1-methyl-anthraquinone- 2-carboxylate (gandavensin E, 2), 2,3,8-trihydroxy-6-methoxy-1-methoxymethyl-anthraquinone (gandavensin F, 3), 8-hydroxy-3,6-dimethoxy-1-methyl-anthraquinone-2-carboxylic acid (gandavensin G, 4) and 1,7-dihydroxy-3,6-dimethoxy-anthraquinone (gandavensin H, 5) on the basis of spectral data. The known compounds isolated for the first time from this plant have been determined to be methyl 3,6,8-trihydroxy-7-methoxy-1-methyl-anthraquinone-2-carboxylate (6), methyl 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (7), 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylic acid (8), 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylic acid (9), 6,8-dihydroxy-3-methoxy-1-methyl-anthraquinone-2-carboxylic acid (10), methyl 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylate (11) and methyl 3,7,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (12).

New anthraquinones from Gladiolus gandavensis.

Two new anthraquinones, methyl 8-hydroxy-3-methoxy-6,7-methylenedioxy-1-methylanthraquinone-2-carboxylate (gandavensin A, 1) and methyl 8-hydroxy-3,6,7-trimethoxy-1-methylanthraquinone-2-carboxylate (gandavensin B, 2), have been isolated from the light petroleum extract of the subterranean corm of Gladiolus gandavensis Van Houtt., along with methyl 8-hydroxy-3,6-dimethoxy-1-methylanthraquinone-2-carboxylate (3), methyl trans-p-methoxycinnamate (4), 5,7-dimethoxy-2-methylchromone (5), and 5-hydroxy-2-hydroxymethyl-7-methoxychromone (6). Their structures were elucidated on the basis of spectral data.

Isolation and Identification of Antioxidant Compounds from Gynura Bicolor Stems and Leaves

The antioxidant compounds in the stems and leaves of Gynura bicolor were studied. 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays were employed to evaluate antioxidant capacity. By solvent extraction and Sephadex LH-20 column chromatography in sequence, ethanol extracts of Gynura bicolor stems and leaves were fractionated to obtain their active fractions, which were further separated to obtain 12 compounds: 1–8 from stems, and four, 8–12, from leaves. Their structures were elucidated on the basis of spectroscopic data (nuclear magnetic resonance and mass spectrometry). Among these substances, compounds 1, 2, 3, 4, and 8 with significant antioxidant activity were determined to be responsible active components for stems, and compounds 4, 8, and 12 for leaves.

Antioxidant compounds from ethanol extracts of bamboo (Neosinocalamus affinis) leaves

Activity-guided fractionation of Neosinocalamus affinis leaves led to obtain two new flavonoids, 4′-O-((7″R,8″S)-8″-guaiacylglyceryl)-pleioside B (9) and apigenin 6-C-β-d-fucopyranosyl-7-O-β-d-glucopyranoside (10) along with eight known compounds. Their structures were elucidated on the basis of spectroscopic data (UV, IR, NMR, and MS). Among these 10 compounds, farobin A (4) and isoorientin (7) showed significant antioxidant activity evaluated by 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), superoxide anion and nitric oxide (NO) radical-scavenging assays.