Hong-Qing Wang

Triterpenoids of Ganoderma theaecolum and their hepatoprotective activities.

Five new lanostane triterpenoids, ganoderic acid XL1 (1), ganoderic acid XL2 (2), 20-hydroxy-ganoderic acid AM1 (3), ganoderenic acid AM1 (4) and ganoderesin C (5), together with five known triterpenoids (6-10) were isolated from the fruiting bodies of Ganoderma theaecolum. Chemical structures were elucidated on the basis of spectroscopic evidence, including 1D, 2D NMR, mass spectrometric data and circular dichroism spectra. Compounds 1, 4, 5, 8, 9 and 10 (10 μM) exhibited hepatoprotective activities against DL-galactosamine-induced cell damage in HL-7702 cells.

Chemical constituents from Inonotus obliquus and their biological activities.

Seven new triterpenes, inonotusol A-G (1-7), one new diterpene, inonotusic acid (8), and 22 known compounds were isolated from Inonotus obliquus. Their structures were elucidated on the basis of spectroscopic analysis, including homonuclear and heteronuclear correlation NMR ((1)H-(1)H COSY, ROESY, HSQC, and HMBC) experiments. In in vitro assays, compounds 6 and 8-16 showed hepatoprotective effects against d-galactosamine-induced WB-F344 cell damage, with inhibitory effects from 34.4% to 81.2%. Compounds 7, 17, and 18 exhibited selective cytotoxicities against KB, Bel-7402, or A-549 cell lines. Compounds 16 and 17 showed inhibitory effects against protein tyrosine kinases, with IC50 values of 24.6 and 7.7 μM, respectively.

Wittiorumins A – F, Antioxidant Diels-Alder-Type Adducts from Morus wittiorum

Six new Diels-Alder-type adducts, wittiorumins A-F ( 1 - 6) along with the three known compounds chalcomoracin ( 7), mulberrofuran J ( 8), and mongolicin F ( 9), were isolated from the stem bark of Morus wittiorum. Their structures including their absolute configurations were determined on the basis of spectroscopic analysis and chemical methods. Some of the isolated compounds ( 1 - 4) were assayed for their antioxidant activities, among which compounds 1 - 3 were active as antioxidants, with inhibitory ratios of 73.0 %, 82.0 %, and 82.0 %, respectively, at a concentration of 10 ( - 5) M.

Isolation and bioactivity of diterpenoids from the roots of Salvia grandifolia.

A phytochemical investigation of root extracts of Salvia grandifolia led to isolation of six previously unreported diterpenoids, grandifolias A-F, along with eight known compounds. The structures of grandifolias A-F were primarily established by extensive 1D and 2D NMR spectroscopic analyses, as well as HRESIMS data. Their absolute configurations were assigned by their calculated and experimental electronic circular dichroism spectra or by X-ray diffraction analysis. All of the diterpenoids were evaluated for their vasorelaxant effects. Grandifolia B and isograndifoliol both exhibited dose-dependent vasorelaxant effects on rat aortic rings, preconstricted by KCl or norepinephrine, with EC50 values of 36.36-74.51μg/mL.

α-Glucosidase-inhibitory iminosugars from the leaves of Suregada glomerulata

A water extract of the leaves of Suregada glomerulata (Euphorbiaceae) was found to inhibit rat small intestinal α-glucosidase. An examination of the extract afforded 20 iminosugars including one pyrrolidine and 19 piperidines. The structures of the 10 new compounds (11-20) were determined by NMR, and MS spectroscopic data analyses, and chemical correlations. The novelty of the identified compounds mainly stems from the loss of a hydroxy at C-4 and the presence of an 8-hydroxyoctyl side chain. Nine N-alkyl derivatives including N-methyl (1a, 8a, and 13a), N-butyl (1b, 2b, and 9b) and N,N-dimethyl (1c, 2c, and 9c) were synthesized. The compounds were tested for rat small intestinal α-glucosidase inhibitory activity. In total, 15 compounds, including compounds 11, 12, 15, and 19 and the three derivatives 8a, 9b, and 13a, showed inhibitory activity with IC50 values less than 40μM. In vivo results showed that total alkaloids of S. glomerulata (10mg/kg) and four major iminosugars 1, 2, 3, and 9 (10mg/kg) can lower the postprandial blood glucose level after sucrose and starch load in healthy male ICR mice.

Anti-inflammatory and cytotoxic 2-arylbenzofurans from Morus wittiorum.

Three new 2-arylbenzofurans named wittifuran H, wittifuran I and wittifuran U (1-3) were obtained during our ongoing investigation of an ethanol extract from the stem bark of Morus wittiorum. Their structures were elucidated on the basis of spectroscopic data. Compound 2 displayed potent anti-inflammatory activity and selective cytotoxicity against human gastric cancer cell line BGC-823 with an IC(50) value of 1.45μM.

Pyrrolidine-type iminosugars from leaves of Suregada glomerulata.

Phytochemical investigation of the H2O extract of leaves of Suregada glomerulata led to the isolation of ten pyrrolidine-type iminosugars. The chemical structures of the six new compounds (4-6, 8-10) were elucidated as 2,5-imino-2,4,5-trideoxy-d-manno-heptitol (4-deoxy-homoDMDP) (4), 2,5-imino-2,4,5-trideoxy-d-gulo-heptitol (5), 2,5-imino-2,4,5,6-tetradeoxy-d-gulo-heptitol (6), 6-C-butyl-4-deoxy-DMDP (8), 6-C-(8-hydroxyoctyl)-DMDP (9), and 6-C-(8-hydroxyoctyl)-2,5-dideoxy-2,5-imino-d-galactitol (10), respectively, on the basis of spectroscopic data analysis (NMR and HRESIMS). Compounds 4-6 and 8 were characterized as rarely seen 4-deoxy pyrrolidine-type iminosugars. Pyrrolidine-type iminosugars with a long-side chain have been found in the restrictive plant families Moraceae, Campanulaceae, and Hyacinthaceae. The discovery of compounds 9 and 10 with a C8 side chain from S. glomerulata (Euphorbiaceae) expands the range of distribution for the iminosugars in plants. The 8-hydroxyoctyl side-chain represents a new addition for the molecular diversity of iminosugars. The compounds 1-10 were evaluated for inhibitory activity against rat intestinal α-glucosidase. However, all the test compounds showed no significant inhibitory activities to the glucosidase.

Aromatic Glucosides from the Seeds of Prunus davidiana

Chemical investigation of the seeds of Prunus davidiana afforded seven new aromatic glucosides, i.e., the prupersins A-E (1-5) and compounds 6 and 7, as well as 11 known compounds. The structures of 1-7 were elucidated by spectroscopic data analysis and chemical evidence, and configurations were determined by hydrolysis experiments (1, 2, and 5) or electronic circular dichroism (6). Compounds 1-6 exhibited antioxidant activity aganist Fe²⁺-cysteine-induced rat liver microsomal lipid peroxidation, with malondialdehyde inhibitory rates of 50-67% and 53-57% at concentrations of 10⁻⁵ and 10⁻⁶ mol/L, respectively.

Five new bioactive compounds from Chenopodium ambrosioides

Five new bioactive compounds, chenopodiumamines A–D (1–4) and chenopodiumoside A (5), were isolated from the ethanol extract of Chenopodium ambrosioides. The structures of these compounds were elucidated by various spectroscopic means (UV, IR, HR-ESI-MS, 1D and 2D NMR). Compounds 1–3 had moderate antioxidant and anti-inflammatory activities.

Three new norsesquiterpenoids from the seeds of Alpinia galanga.

From the seeds of Alpinia galanga Willd., three new norsesquiterpenoid racemic mixtures, galanols A–C (1–3) were isolated, along with three known sesquiterpenoids (4–6). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D NMR and 2D NMR spectroscopic data.