An Oxazole Alkaloid, Terpenoids, and Cyclodipeptides With Cytotoxic and Nitric Oxide Inhibitory Effects From a Mangrove-Derived Fungus Trichoderma sp. GXT-22.1.

Chemical investigation of the mangrove-derived fungus Trichoderma sp. GXT-22.1 led to the isolation and identification of 10 secondary metabolites, including one new compound, 5'-(4-methoxyphenyl)-1',3'-oxazole (1), one new natural compound, (E)-6,10-dimethyl-5-undecene-2,9,10-triol (2), along with eight known compounds, tricholumin A (3), harzianol J (4), cyclonerodiol (5), 10,11-dihydro-11-hydroxycyclonerodiol (6), cyclonerodiol B (7), epicyclonerodiol oxide (8), cyclo(Val-Pro) (9), and cyclo-(4-hydroxyprolinyl-leucine) (10).

Culcinoside E, a new sulfated steroidal biglycoside from the starfish .

Using various chromatographic separations, six steroid glycoside derivatives, including one new compound named culcinoside E (), were isolated from the methanol extract of the starfish . Their structures were confirmed by detailed analysis of the 1D, 2D NMR, and HR ESI QTOF mass spectra. Among isolated compounds, culcinoside E (), diplasterioside A (), and thornasteroside A () inhibited growth of , whereas culcitoside C () was active on .

Acylated flavonoid glycosides from Barringtonia pendula and their inhibition on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells.

Six new acylated flavonoid glycosides namely barringosides J - O (1-6) along with tephrokaempferoside and barringoside D were isolated from the branches and leaves of Barringtonia pendula. The structural elucidation was confirmed by extensive analysis of their spectroscopic data including HRQTOFMS, 1D and 2D NMR experiments. Moderate inhibitory effects on LPS-induced NO production in RAW264.

Asterosaponins from the starfish .

Five asterosaponins (-), including one new compound named protonodososide (), were isolated from the methanol extract of the starfish , after subjecting to various chromatographic separations. The structural elucidation was confirmed by careful analysis of the 1D, 2D NMR, and HR ESI QTOF mass spectra. The cytotoxicity of isolated compounds was evaluated on five human cancer cell lines including HepG2, KB, MCF7, LNCaP, and SK-Mel2.

Isoryanodane diterpene derivatives from .

From the MeOH residue of branches and leaves, one new isoryanodane diterpene, barringisol (), and two new isoryanodane diterpene glucosides, barringisosides A and B ( and ), were obtained using various chromatographic isolations. The structural characterization was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-QTOF-MS. This is the first isolation of isoryanodane diterpene derivatives from species.

Polyhydroxylated steroid derivatives from the starfish .

A new polyhydroxysteroid glycoside, regulusoside D (), and a new polyhydroxylated steroid, (24)-cholestane-3,5,6,8,15,24-hexol (), together with seven known compounds were purified from the starfish collected near Con Co Islands, Vietnam. The structure elucidation was confirmed by extensive analysis of their NMR and HR-QTOF mass experiments. Among isolated compounds, regulusoside D (), (24)-cholestane-3,5,6,8,15,24-hexol (), granulatoside A (), 5-cholestane-3,6,7α,15,16,26-hexol (), 5-cholestane-3,6,7,8,15,16,26-heptol () and 5-cholestane-3,6,8,15,16,26-hexol () exhibited strong inhibitory effects on LPS-induced NO production in RAW264.

Cytotoxic constituents from .

In our search for cytotoxic constituents from Vietnamese plants, the methanolic extract of was found to exhibit significant cytotoxic effect. Subsequent phytochemical investigation of ethyl acetate fractions of this plant led to isolation of 11 compounds including one new arylbenzofuran rhamnoside namely aristolochiaside (), two aristololactams ( and ), three lignanamides (-) and five phenolic amides (-). Their structures were elucidated by 1 D and 2 D NMR and HR-QTOF-MS experiments.

Acylated flavonoid glycosides from .

Using various chromatographic separations, three new acylated flavonoid glycosides, namely barringosides G-I (-), were isolated from the water-soluble extract of branches and leaves. The structure elucidation was performed by extensive analysis of the 1D and 2D NMR and HR-QTOF-MS data. Of the isolated compounds, barringoside I () showed moderate inhibitory effects on LPS-induced NO production in RAW264.

Triterpene glycosides from the Vietnamese sea cucumber .

From the MeOH extract of the Vietnamese sea cucumber , eight triterpene glycosides (-), including one new compound namely holothurin A (), were isolated by using various chromatographic separations. Their structures were established by spectroscopic experiments including 1D, 2D NMR and HR-ESI-MS. Holothurin A () has a hydroperoxy group at C-25.

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.

Triterpene tetraglycosides from the sea cucumber Stichopus horrens.

Using various chromatographic separations, three triterpene tetraglycosides (1-3), including one new compound, namely stichorrenoside E (1) along with thelenotoside B (2) and deacetyl thelenotoside B (3), were isolated from the MeOH extract of the Vietnamese sea cucumber Stichopus horrens. Their structures were confirmed by spectroscopic experiments, such as 1D and 2D NMR and HR-ESI-MS. Deacetylated thelenotoside B (3) is firstly isolated as a natural product.

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.

Cytotoxic triterpene diglycosides from the sea cucumber Stichopus horrens.

Using various chromatographic separation techniques, eight triterpene diglycosides (1-8), including four new compounds namely stichorrenosides A-D (1-4), were isolated from a methanol extract of the Vietnamese sea cucumber S. horrens. Their structures were elucidated based on spectroscopic analyses, including HR ESI MS, 1D and 2D NMR.

Polar steroid derivatives from the Vietnamese starfish Astropecten polyacanthus.

Five polar steroid derivatives, including one new glycosylated polyhydroxysteroid namely polyacanthoside A (1), were isolated from the water-soluble materials from the MeOH extract of the Vietnamese starfish Astropecten polyacanthus using various chromatographic separations. The structure elucidation was confirmed by spectroscopic experiments such as HR-ESI-MS, 1D and 2D NMR. Among the isolated compounds, (20R,24S)-3β,6α,8,15β,24-pentahydroxy-5α-cholestane (3) showed significant cytotoxic effect against five human cancer cell lines as HepG2, KB, LNCaP, MCF7 and SK-Mel2 with the IC values from 18.

Triterpene saponins and megastigmane glucosides from Camellia bugiamapensis.

Two new triterpene saponins, camelliosides I and J (1 and 2), two new megastigmane glycosides, camellistigosides A and B (3 and 4), and two known megastigmane glycosides, icariside B (5) and (6S,9R)-roseoside (6), were isolated from a methanol extract of the Camellia bugiamapensis leaves using various chromatographic separation techniques. Their structures were elucidated based on spectroscopic analyses, including HR ESI MS, CD, 1D and 2D NMR. Their inhibitory effects on LPS-induced NO production in RAW264.

Pyrrole Oligoglycosides from the Starfish Acanthaster planci Suppress Lipopolysaccharide-Induced Nitric Oxide Production in RAW264.7 Macrophages.

Two new pyrrole oligoglycosides, plancipyrrosides A and B (1 and 2), were isolated from methanol extract of the Vietnamese starfish Acanthaster planci using various chromatographic procedures. Their structures were elucidated by spectroscopic methods including one and two dimensional (1D- and 2D)-NMR and Fourier transform ion cyclotron resonance (FT-ICR)-MS. The finding of 1 and 2 represents the third case of pyrrole oligoglycosides obtaining reported to date.

Further Highly Hydroxylated Steroids from the Vietnamese Starfish Archaster typicus.

Eight highly hydroxylated steroids (1-8), including three new compounds as sodium salts of (24S)-5α-cholestane-3β,4β,5,6α,7β,8,14,15α,24-nonaol 6-sulfate (1), (24E)-5α-cholest-24-ene-26-yde-3β,6α,8,14,15α-pentaol 15-sulfate (2), and 5α-cholest-3β,6α,8,14,15α,24,25,26-octaol 15-sulfate (3), were isolated and elucidated from the methanol extract of the Vietnamese starfish Archaster typicus. The structure elucidation was done by spectroscopic methods including one and two dimensional (1D-, 2D-)NMR and Fourier transform ion cyclotron resonance (FT-ICR)-MS. The isolated compounds can be used as chemical markers for taxonomic identification of the starfish A.

Steroid glycosides from the starfish Pentaceraster gracilis.

Using combined chromatographic separations, two new steroid glycosides namely pentacerosides A (1) and B (2), and four known compounds were isolated from the methanol extract of the starfish Pentaceraster gracilis. Their structures were determined on the basis of spectroscopic data (H and C NMR, HSQC, HMBC, H-H COSY, ROESY, and FT-ICR-MS) and by comparing obtained results to the literature values. Among the isolated compounds, only maculatoside (5) showed significant cytotoxic effect against Hep-G2 (IC = 16.

Two new simple iridoids from the ant-plant Myrmecodia tuberosa and their antimicrobial effects.

Six iridoid derivatives (1-6), including two new compounds myrmecodoides A and B (1 and 2), were isolated from the ant-plant Myrmecodia tuberosa. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, NOESY and HR-ESI-MS) and by comparison with the literature values. Among isolates, 3 and 4 exhibit weak antibacterial effect against Staphylococcus aureus subsp.

Cytotoxic triterpene saponins from Cercodemas anceps.

Seven holostane-type triterpene saponins (1-7), including five new compounds namely cercodemasoides A-E (2-6), were isolated from the sea cucumber Cercodemas anceps. Their structures were elucidated on the basis of spectroscopic evidence including HR ESI MS, ESI MS/MS, 1D and 2D NMR. The cytotoxic effects of isolated compounds were evaluated by SRB method on five human cancer cell lines including Hep-G2 (hepatoma cancer), KB (epidermoid carcinoma), LNCaP (prostate cancer), MCF7 (breast cancer), and SK-Mel2 (melanoma).

Asterosaponins and glycosylated polyhydroxysteroids from the starfish Culcita novaeguineae and their cytotoxic activities.

Using combined chromatographic methods, two asterosaponins (compounds 1 and 2), including a new compound novaeguinoside E (compound 1), and six glycosylated polyhydroxysteroids (compounds 3-8) were isolated from a methanol extract of the starfish Culcita novaeguineae. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, ROESY, and HRESI-MS) and by comparison with the literature values. The new compound 1 represents the third example of asterosaponins containing the 5α-cholesta-9(1l)-en-3β,6α,20,22-tetraol aglycone.