Hoang Thanh Huong

Pentacyclic triterpenoids from Mallotus apelta.

A new triterpene (1) and six known pentacyclic terpenoids (2-7) were isolated from the methanol extract of the dried leaves fromMallotus apelta. Based on the spectral and chemical evidence, their structures were determined to be 3α-hydroxyhop-22(29)-ene (1), hennadiol (2), friedelin (3), friedelanol (4), epifriedelanol (5), taraxerone (6), and epitaraxerol (7).

C29 sterols with a cyclopropane ring at C-25 and 26 from the Vietnamese marine sponge Ianthella sp. and their anticancer properties.

Two new C(29) sterols with a cyclopropane ring at C-25 and C-26, petrosterol-3,6-dione (1) and 5alpha,6alpha-epoxy-petrosterol (2), along with petrosterol (3), were isolated from the Vietnamese marine sponge Ianthella sp. The structures of the new compounds were elucidated by comprehensive spectroscopic analyses. Compounds 1-3 showed cytotoxic activities on A549, HL-60, MCF-7, SK-OV-3, and U937 cancer cell lines with IC(50) in the range of 8.4-22.6 microM, whereas compounds 1-3 exhibited only weak cytotoxic activities on HT-29 cell. After HL-60 cells were treated with the compounds, several apoptosis events like chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. These data supported that the compounds might have potential for leukemia treatment.

Cytotoxic and anti-inflammatory cembranoids from the Vietnamese soft coral Lobophytum laevigatum

Four new cembranoids, namely laevigatol A-D (1-4), and six known metabolites (5-10), were isolated from the Vietnamese soft coral Lobophytum laevigatum. The structures of these compounds were elucidated by extensive spectroscopic analyses, and the absolute stereochemistry of 1 was determined using the modified Moshers method. Compounds 5, and 7-10 exhibited cytotoxic activity against selected human cancer cell lines. Compounds 1, 2, 8, and 9 showed dose-dependent inhibitory effects on the TNFα-induced NF-κB transcriptional activity in Hep-G2 cells. Moreover, compounds 1, 2, 8, and 9 significantly inhibited the induction of COX-2 and iNOS mRNA dose-dependently, indicating that these compounds attenuated the synthesis of these transcripts at the transcriptional level.

Phenolic constituents with inhibitory activity against NFAT transcription from Desmos chinensis.

Six phenolic constituents, 2-methoxybenzyl benzoate (1), negletein (2), 2’,3’-dihydroxy-4’,6’-dimethoxydihydrochalcone (3), 5, 6-dihydroxy-7-methoxy-dihydroflavone (4), astilbin (5), and quercitrin (6) were isolated from the methanol extract of the dried leaves ofDesmos chinensis. Their structures were elucidated from spectral and chemical data. Of these constituents, compounds 2 (IC50: 3.89 ± 0.39 μM) and3 (IC50: 9.77 ± 0.26 μM) exhibited potent inhibitory activity against nuclear factor of activated T cells (NFAT) transcription factor, and compound1 (IC50: 28.4 ± 2.62 μM) exhibited moderate inhibitory activity.

Inhibitors of Osteoclast Formation from Rhizomes of Cibotium barometz

Eight compounds (1-8) were isolated from a methanol extract of Cibotium barometz rhizomes including two new furan derivatives, cibotiumbarosides A (1) and B (2), and a new glycoglycerolipid, cibotiglycerol (4). Their structures were elucidated by chemical and spectroscopic methods. Compounds 2-5 each showed inhibition of osteoclast formation with no affect on BMM cell viability.

Aporphine alkaloids, clerodane diterpenes, and other constituents from Tinospora cordifolia

Phytochemical investigation of the methanol extract of Tinospora cordifolia aerial parts led to the isolation of four new and seven known compounds. The structures of two new aporphine alkaloids, N-formylasimilobine 2-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (tinoscorside A, 1) and N-acetylasimilobine 2-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (tinoscorside B, 2), a new clerodane diterpene, tinoscorside C (3), and a new phenylpropanoid, sinapyl 4-O-beta-D-apiofuranosyl-(1-->6)-O-beta-D-glucopyranoside (tinoscorside D, 6) were determined by extensive spectroscopic methods including FTICR-MS and 1D and 2D NMR.

New phenylpropanoid esters of sucrose from Polygonum hydropiper and their antioxidant activity

By various chromatographic methods, two new phenylpropanoid esters of sucrose named hidropiperosides A (1) and B (2), and three known compounds as vanicosides A (3), B (4), and E (5) were isolated from the methanolic extract of the whole plant of Polygonum hydropiper L. (Polygonaceae). Their structures were elucidated by extensive spectroscopic methods including 1D-and 2D-NMR experiments, as well as ESI-MS analysis. All the isolated compounds were tested for their antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay system. Among them, compounds 2 and 3 showed significant antioxidant activity with their SC50 values of 23.4 and 26.7 μg/mL, respectively.

Chemical Components from the Vietnamese Soft Coral Lobophytum sp.

Chromatographic separation resulted in the identification of one new squalene derivative, named lobophytene (1), three cembranoid diterpenes (2–4), and two sterols (5 and 6) from the Vietnamese marine soft coral Lobophytum sp. Their structures were identified on the basis of extensive spectroscopic data and comparison of those with reported data. Compounds 1 and 2 showed significant cytotoxic activities against lung (A549) and colon (HT-29) cell lines with IC50 values of 8.2 and 5.6 μM for 1; 5.1 and 1.8 μM for 2, respectively.

Dibenzocyclooctadiene lignans and lanostane derivatives from the roots of Kadsura coccinea and their protective effects on primary rat hepatocyte injury induced by t-butyl hydroperoxide.

A new dibenzocyclooctadiene lignan, acetylepigomisin R ( 1), and a new 3,4-seco-lanostane-type triterpene, seco-coccinic acid F ( 2), along with three known dibenzocyclooctadiene lignans, isovaleroylbinankadsurin A ( 3), kadsuralignan J ( 4), and binankadsurin A ( 5), and one lanostane-type triterpene, 20( R),24( E)-3-oxo-9 beta-lanosta-7,24-dien-26-oic acid ( 6), were isolated from the methanol extract of the Kadsura coccinea roots. Their structures were elucidated on the basis of spectroscopic evidence including ESI-MS, HR-EI-MS, 1D and 2D NMR. The protective effects of these compounds were evaluated in primary cultured rat hepatocytes intoxicated with 1.2 mM T-butyl hydroperoxide. Compounds 1, 3, and 5 showed protective effects with ED (50) values of 135.7, 26.1, and 79.3 microM, respectively.

New cytotoxic benzopyrans from the leaves ofMallotus apelta

Two new benzopyrans 6-[1′-oxo-3′(R)-hydroxy-butyl]-5, 7-dimethoxy-2,2-dimethyl-2H-1-benzopyran (1) and 6-[1′-oxo-3′(R)-methoxy-butyl]-5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran (2) were isolated from the leaves ofMallotus apelta Muell.-Arg., (Euphorbiaceae). Their chemical structures were elucidated by spectroscopic analyses, especially by 1D- 2D-NMR and MS spectra. Compound1 was found to have strong cytotoxic effect against two human cancer cell lines as human hepatocellular carcinoma (Hep-2, IC50: 0.49 μg/mL) and rhabdosarcoma (RD, IC50: 0.54 μg/mL), while compound2 showed moderate activity against Hep-2 cell line (IC50, 4.22μg/mL), byin vitro assay.