Phan Thi Thanh Huong

Pyrrole and furan oligoglycosides from the starfish Asterina batheri and their inhibitory effect on the production of pro-inflammatory cytokines in lipopolysaccharide-stimulated bone marrow-derived dendritic cells.

Three new pyrrole oligoglycosides, astebatheriosides A-C (1-3), and a new furan oligoglycoside, astebatherioside D (4), were isolated from the starfish Asterina batheri by various chromatographic methods. Their structures were elucidated by spectroscopic and chemical methods. Compounds 2, 3, and 4 moderately inhibited IL-12 p40 production in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) with IC50 values of 36.4, 31.6, and 22.8μM, respectively.

A new prenylated aurone from Artocarpus altilis

Phytochemical study of the methanol extract of Artocarpus altilis resulted in the isolation of a new prenylated aurone, artocarpaurone (1), together with eight known compounds including two prenylated chalcones (2 and 3), three prenylated flavanones (4–6), and three triterpenes (7–9). The structure of 1 was elucidated as 6-hydroxy-2-[8-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-5-ylmethylene]-3(2H)-benzofuranone by spectroscopic methods including 1D and 2D NMR spectra and FT-ICR-MS. Compound 1 showed moderate nitric oxide radical scavenging activity, whereas 2 and 3 had moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect, compared with the positive control (+)-catechin.

New Steroidal Glycosides from the Starfish Acanthaster planci

Two new and three known polyhydroxysteroid glycosides were isolated from the MeOH extract of the starfish Acanthaster planci. The structures of the isolated compounds were elucidated using NMR and mass spectrometry. The new glycosides had the same aglycon, (24S)-24-methyl-5α-cholestane-3β,4β,6α,8,15β,16β,28-heptaol, and different carbohydrate fragments,2-O-methyl-β-D-xylopyranosyl-(1→2)-β-D-galactofuranose and 5-O-sulfo-α-L-arabinofuranose, bonded to the C-28 position of the 24-methylcholestane side chain.

A new rearranged abietane diterpene from Clerodendrum inerme with antioxidant and cytotoxic activities

Abstract Eight compounds were isolated from the leaves of Clerodendrum inerme, including one new rearranged abietane diterpene, crolerodendrum B (1). Their structures were determined by means of spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance (1-D and 2-DNMR), high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) and circular dichroism (CD). The DPPH radical scavenging and cytotoxic activities of isolated compounds against MCF7 (breast), HCT116 (colon) and B16F10 (melanoma) cancer cell lines were evaluated. Compounds 1, 3 and 4 exhibited strong DPPH radical-scavenging effects (ED50 values of 17.6 ± 2.1, 10.1 ± 0.8 and 11.3 ± 0.3 μM, respectively) and 4 showed strong cytotoxicity against the HCT116 cell line (IC50 = 3.46 ± 0.01 μM).

Flavonoid glycosides from Barringtonia acutangula

Using various chromatographic separation techniques, ten flavonoid glycosides, including six new compounds namely barringosides A-F (1-6), were isolated from a methanol extract of the Barringtonia acutangula leaves. The structure elucidation was confirmed by spectroscopic analyses, including 1D and 2D NMR, and HR ESI MS. Their inhibitory effects on LPS-induced NO production in RAW264.7 cells were also evaluated. Among the isolated compounds, quercetin 3-O-β-d-(6-p-hydroxybenzoyl)galactopyranoside (9) showed significant effect with an IC50 of 20.00±1.68µM. This is the first report of these flavonoid glycosides from Barringtonia genus and their inhibition on LPS-induced NO production in RAW264.7 cells was reported here for the first time.

STRUCTURE ELUCIDATION AND CYTOTOXIC ACTIVITY OF ATTENUATOSIDE B-1, PLANCISIDE A, AND CULCITOSIDE C2 FROM THE STARFISH ACANTHASTER PLANCI

Detailed analysis of the 1D and 2D NMR data and comparison with the reported values, the structures of attenuatoside B-1 ( 1 ), planciside A ( 2 ), and culcitoside C 2 ( 3 ) from starfish Acanthaster planci were clearly elucidated. Culcitoside C 2 ( 3 ) showed weak cytotoxic activity against five human cancer cell lines including HepG2, KB, LNCaP, MCF7, and SK-Mel2.

Anthraquinone and Butenolide Constituents from the Crinoid Capillaster multiradiatus

Seven anthraquinones including two new compounds namely capillasterquinones A and B (1 and 2) and one new butenolide namely capillasterolide (8) were isolated and structurally elucidated from the crinoid Capillaster multiradiatus. The inhibitory effect of compounds 1-8 on lipopolysaccharide (LPS)-induced nitric oxide (NO) production as well as inhibition of 1 on expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) proteins in RAW264.7 cells were also evaluated. As the obtained results, capillasterquinone A (1) showed strong NO production inhibitory activity with an IC50 of 5.89±0.11 µM. In addition, compound 1 reduced the LPS-induced iNOS and COX-2 expressions in a dose-dependent manner.

Two new guaiane sesquiterpene lactones from the aerial parts of Artemisia vulgaris

Abstract Two new guaiane sesquiterpene lactones, vulgarolides A and B (1 and 2), were isolated from Artemisia vulgaris aerial parts using various chromatographic separations. The structure elucidation was performed by combination of spectroscopic experiments including 1D and 2D NMR, HR ESI MS, and CD. Their in vitro cytotoxic activities against five human cancer cell lines were also evaluated using SRB method.

ANTIMICROBIAL COMPOUNDS FROM RHIZOPHORA STYLOSA

( 6S,7E,9R )-6,9-dihydroxy-4,7-megastiymadien-3-one 9- O -[ α -L-arabinopyranosyl-(l→6)- β -D-glucopyranoside] ( 1 ), blumenol A ( 2 ), and kaempferol 3-rutinoside ( 3 ) were isolated from the methanol extract of the leaves of mangrove plant Rhizophora stylosa Griff. Structural elucidation of the metabolites was carried out by analysis of their spectroscopic data and by comparison with those reported in the literature. All these compounds exhibited antimicrobial activity and were isolated from this genus for the first time.

Saponins isolated from the Vietnamese sea cucumber Stichopus chloronotus.

Using various chromatographic methods, three triterpene saponins neothyonidioside ( 1 ), stichoposide D ( 2 ), and holothurin B ( 3 ), were isolated from the methanol extract of the sea cucumber Stichopus chloronotus . Their structures were elucidated by 1D and 2D-NMR experiments and comparison of their NMR data with reported values. Compound 1 was isolated from S. chloronotus for the first time.