Hui-ang Li

Acylated Iridoids with Cytotoxicity from Valeriana jatamansi

Thirteen new acylated iridoids, jatamanvaltrates A-M (1-13), together with nine known valepotriates (14-22), were isolated from the whole plants of Valeriana jatamansi (syn. Valeriana wallichii). The structures of these new compounds were assigned by detailed interpretation of spectroscopic data. Jatamanvaltrates D (4) and H (9) are the first examples of naturally occurring valepotriates containing an o-hydroxybenzoyloxy moiety at C-10. All isolated compounds were tested for their cytotoxicity against lung adenocarcinoma (A549), metastatic prostate cancer (PC-3M), colon cancer (HCT-8), and hepatoma (Bel7402) cell lines.

Protective effects of dehydrocavidine on carbon tetrachloride-induced acute hepatotoxicity in rats.

AIM OF THE STUDY To investigate the protective effects of dehydrocavidine (DC), a main active ingredient of Corydalis saxicola Bunting (Yanhuanglian), on carbon tetrachloride (CCl4)-induced hepatotoxicity and the possible mechanisms involved in male Sprague-Dawley rats. MATERIALS AND METHODS Acute hepatotoxicity was induced by CCl4 intoxication in rats. Serum biological analysis, lipid peroxides and antioxidants estimation, histopathological studies were carried out. RESULTS Both pre-treatment with DC prior to CCl4 administration and post-treatment with DC after CCl4 administration significantly prevented increases in serum enzymatic activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and total bilirubin (TBIL). In addition, pre- and post-treatment with DC also significantly prevented formation of hepatic malondialdehyde (MDA), depletion of glutathione peroxidase (GPx) and depression of superoxide dismutase (SOD) in the liver of CCl4-intoxicated rats. ALT, AST, LDH, ALP and TBILL levels, as well as MDA, SOD and GPx activities were unaffected in normal rats by treatment with DC alone. GST, a phase II enzyme, had no significant changes during our experiments. Histopathological changes induced by CCl4 were also significantly attenuated by DC treatment in both preventive and curative experiments. CONCLUSIONS DC has a potent hepatoprotective effect on CCl4-induced liver injury in rats through its antioxidant activity.

Ainsliadimer A, a new sesquiterpene lactone dimer with an unusual carbon skeleton from Ainsliaea macrocephala.

A phytochemical investigation of Ainsliaea macrocephala led to the isolation of a new dimeric sesquiterpene lactone, ainsliadimer A (1). The structure of 1 was elucidated by spectroscopic analysis, and confirmed by single crystal X-ray diffraction. Ainsliadimer A represents an unusual carbon skeleton with a cyclopentane system connecting the two monomeric sesquiterpene lactone units. This unique molecule exerted potent inhibitory activity against the production of nitric oxide in RAW264.7 stimulated by LPS.

New thiazinediones and other components from Xanthium strumarium

Two new thiazinediones along with five known compounds were isolated from the fruits of Xanthium strumarium L. The structures of the two new compounds were determined to be 7-hydroxymethyl-8,8-dimethyl-4,8-dihydrobenzol[1,4]thiazine-3,5-dione-11-O-β-D-glucopyranoside (1) and 2-hydroxy-7-hydroxymethyl-8,8-dimethyl-4,8-dihydrobenzol[1,4]thiazine-3,5-dione-11-O-β-D-glucopyranoside (2). The five known compounds were identified as xanthiazone (3), chlorogenic acid (4), ferulic acid (5), formononetin (6), and ononin (7), respectively.

Differentiation potential of human embryonic mesenchymal stem cells for skin‐related tissue

Background  Mesenchymal stem cells (MSC) have the capacity to differentiate into cells of connective tissue lineages, including bone, fat, cartilage and muscle, but the differentiation of embryonic MSC into epidermal cells by mesenchymal‐epithelial transition has not been confirmed.

Alkaloids from Corydalis saxicola and Their Anti‐Hepatitis B Virus Activity

Eight protoberberine‐type alkaloids and two indole alkaloids were isolated from the MeOH extracts of the herb Corydalis saxicola Bunting (Papaveraceae). Their structures were identified as dehydrocavidine (1), dehydroapocavidine (2), dehydroisoapocavidine (3), berberine (4), dehydroisocorypalmine (5), coptisine (6), tetradehydroscoulerine (7), berbinium (8), 1‐formyl‐5‐methoxy‐6‐methylindoline (9), and 1‐formyl‐2‐hydroxy‐5‐methoxy‐6‐methylindoline (10). Compounds 3, 9, and 10 are new alkaloids. All compounds were tested for anti‐HBV activity against the 2.2.15 cell line in vitro. Dehydrocavidine (1), dehydroapocavidine (2), and dehydroisoapocavidine (3) exhibited inhibitory activity against HBsAg and HBeAg, but no cytotoxicity against the 2.2.15 cell line.

Chemical constituents of Crinum asiaticum L. var. sinicum Baker and their cytotoxic activities.

A phytochemical investigation of the bulbs of Crinum asiaticum L. var. sinicum Baker resulted in the isolation of two new alkaloids, asiaticumines A and B (1 and 2, resp.), together with 21 known compounds, including nine alkaloids, four amides, five phenolic compounds, and three flavonoids. All 23 compounds were isolated for the first time from Crinum asiaticum L. var. sinicum Baker. Their structures were elucidated by spectroscopic methods. In addition, ten alkaloids, 1–10, were evaluated for their cytotoxic activities against human tumor cell lines A549, LOVO, HL‐60, and 6T‐CEM. Compounds 3, 4, and 7–10 selectively showed remarkable inhibition against one or more of the tested cell lines.

Qualitative and quantitative determination of the major coumarins in Zushima by high performance liquid chromatography with diode array detector and mass spectrometry.

A method, high-performance liquid chromatography coupled with diode array and electrospray tandem mass spectrometry (HPLC-DAD-ESI-MS), was developed to qualitatively identify and quantitatively determine the 10 major active coumarins of Zushima. The analysis was performed by using a ZORBAX SB-C18 analytical column (250 mm x 4.6 mm ID, 5 microm) at gradient elution of 0.5% aqueous formic acid and acetonitrile with diode array detection (325 nm). The method was validated for linearity, precision, accuracy, limit of detection and quantification. The proposed method was successfully applied for the qualitative and quantitative analysis of 10 coumarins in five different species of Zushima which had great variation on the contents of investigated coumarins.

Incarvilleatone, a new cyclohexylethanoid dimer from Incarvillea younghusbandii and its inhibition against nitric oxide (NO) release.

Incarvilleatone (1), an unprecedented dimeric cyclohexylethanoid analog with a racemic nature, was isolated from the whole plant of Incarvillea younghusbandii. HPLC chiral separation of 1 gave two enantiomers (-)-incarvilleatone and (+)-incarvilleatone. The structure of 1 was established by spectroscopic methods and single crystal X-ray diffraction. The absolute configurations of enantiomers were determined by quantum mechanical calculation. (-)-Incarvilleatone exhibited a potent inhibitory effect against NO production in LPS-induced RAW264.7 macrophages.

Revision of the structures of 1,5-dihydroxy-3,8-epoxyvalechlorine, volvaltrate B, and valeriotetrate C from Valeriana jatamansi and V. officinalis.

The structures of 1,5-dihydroxy-3,8-epoxyvalechlorine (1a) and volvaltrate B (6a), two new chlorinated iridoids isolated from Valeriana jatamansi and V. officinalis, respectively, were originally assigned on the basis of spectroscopic methods. Reinvestigation using X-ray analysis and chemical transformation revealed that the original assignment of H-7 in 1a and OH-8 in 6a should be inverted and that the structures should be revised to 1 and 6, respectively. Correspondingly, the structure of valeriotetrate C (7a) should be revised to 7. Volvaltrate B (6) showed cytotoxic activity against the lung adenocarcinoma (A549), metastatic prostate cancer (PC-3M), colon cancer (HCT-8), and hepatoma (Bel7402) cell lines, with IC50 values of 8.5, 2.0, 3.2, and 6.1 μM, respectively.