Preparation and cellular protection against oxidation of Konjac oligosaccharides obtained by combination of γ-irradiation and enzymatic hydrolysis.

Konjac glucomannan (KGM) is an important source for preparation of Konjac oligo-glucomannan (KOG), but high molecular weight and viscosity in KGM inhibited its full degradation into KOG. In this study, KOG with a degree of polymerization between 2 and 9 was obtained by combining γ-irradiation and enzymatic hydrolysis in high yield. We investigated the protective effect of KOG against H2O2 - induced oxidative damage in vitro, using human hepatic cell line (LO2) as a cell model. Our results demonstrated that pretreating LO2 with KOG significantly increases cellular survival and antioxidant activities of GSH-Px and CAT enzymes, and reduces levels of LDH, MDA, intracellular accumulation of ROS and Ca2+ concentration within the cell. Marked protective effect against oxidative damage, in addition to obtained high yield of KOG, supports its potential use as an abundant source of antioxidant. To conclude, our study provided a theoretical perspective for future uses of KGM.

Cladieunicellin J, a new hydroperoxyeunicellin from cladiella sp.

A new 6-hydroperoxyeunicellin diterpenoid, designated as cladieunicellin J (1), was isolated from an octocoral Cladiella sp., and its structure elucidated by spectroscopic methods. Compound 1 was found to exhibit cytotoxicity toward CCRF-CEM human T-cell acute lymphoblastic leukemia.

Three new clerodane diterpenes from Polyalthia longifolia var. pendula.

Three new clerodane diterpenes, (4→2)-abeo-cleroda-2,13E-dien-2,14-dioic acid (1), (4→2)-abeo-2,13-diformyl-cleroda-2,13E-dien-14-oic acid (2), and 16(R&S)- methoxycleroda-4(18),13-dien-15,16-olide (3), were isolated from the unripe fruit of Polyalthia longifolia var. pendula (Annonaceae) together with five known compounds (4-8). The structures of all isolates were determined by spectroscopic analysis. The anti-inflammatory activity of the isolates was evaluated by testing their inhibitory effect on NO production in LPS-stimulated RAW 264.7 macrophages. Among the isolated compounds, 16-hydroxycleroda-3,13-dien-15,16-olide (6) and 16-oxocleroda-3,13-dien-15-oic acid (7) showed promising NO inhibitory activity at 10 µg/mL, with 81.1% and 86.3%, inhibition, respectively.

Cembrane derivatives from the soft corals, Sinularia gaweli and Sinularia flexibilis.

A new norcembranoidal diterpene, 1-epi-sinulanorcembranolide A (1), and a new cembranoidal diterpene, flexibilin D (2), were isolated from the soft corals, Sinularia gaweli and Sinularia flexibilis, respectively. The structures of new metabolites 1 and 2 were elucidated by spectroscopic methods, and compound 2 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 proteins of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. In addition, S. flexibilis yielded a known cembrane, 5-dehydrosinulariolide (3); the structure, including its absolute stereochemistry, was further confirmed by single-crystal X-ray diffraction analysis.

A new 5α,8α-Epidioxysterol from the soft coral Sinularia gaweli.

A new sterol, (22R,23R,24R)-5α,8α-epidioxy-22,23-methylene-24-methyl-cholest-6,9(11)-dien-3ß-ol (1), and two known sterols, (22R,23R,24R)-5α,8α-epidioxy-22,23-methylene-24-methylcholest-6-en-3ß-ol (2) and 24-methylenecholestane-1α,3ß,5α, 6ß,11α-pentol (3), were isolated from the soft coral Sinularia gaweli. The structure of sterol 1 was established by spectroscopic methods and by comparison of the spectral data with those of known analogues. The cytotoxicity of sterols 1-3 towards various tumor cells is reported.

Pseudoalteromone B: a novel 15C compound from a marine bacterium Pseudoalteromonas sp. CGH2XX.

A novel 15C compound, pseudoalteromone B (1), possessing a novel carbon skeleton, was obtained from a marine bacterium Pseudoalteromonas sp. CGH2XX. This bacterium was originally isolated from a cultured-type octocoral Lobophytum crassum, that was growing in cultivating tanks equipped with a flow-through sea water system. The structure of 1 was established by spectroscopic methods. Pseudoalteromone B (1) displayed a modestly inhibitory effect on the release of elastase by human neutrophils.

Anti-inflammatory cembranoids from the Formosan soft coral Sinularia discrepans.

A new cembranoid, discrepanolide A (1), along with four known cembranoids 2-5 were isolated from the Formosan soft coral Sinularia discrepans. The structures of these compounds were determined by analysis of spectroscopic data and by comparison of NMR data with those of known compounds. None of these compounds were found to be cytotoxic towards a limited panel of cancer cell lines. Compounds 3-5 were found to display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Compound 5 also significantly inhibited the accumulation of pro-inflammatory COX-2 protein.

(-)-Hydroxylindestrenolide, a new sesquiterpenoid from a gorgonian coral Menella sp. (Plexauridae).

(-)-Hydroxylindestrenolide (1), an enantiomer of the known sesquiterpenoid, (+)-hydroxylindestrenolide (2), was isolated from a gorgonian coral identified as Menella sp. The structure, including the relative stereochemistry of 1 was established by spectroscopic methods and by comparison the spectral and physical data with those of 2. Sesquiterpenoid 1 exhibited marginal cytotoxicity toward HL-60 and K562 leukemia tumor cells, and displayed a weak inhibitory effect on superoxide anion generation at a concentration of 10 µg/ml by human neutrophils.

Cladieunicellins A-E, new eunicellins from an Indonesian soft coral Cladiella sp.

Five new eunicellin-type diterpenoids, cladieunicellins A-E (1-5), were isolated from an Indonesian soft coral identified as Cladiella sp. The structures of diterpenoids 1-5 were established using spectroscopic methods. Eunicellins 2 and 5 were found to be cytotoxic against DLD-1 and HL-60 tumor cells, respectively, and 3 displayed inhibitory effects against superoxide anion generation by human neutrophils.

Carijoside A, a bioactive sterol glycoside from an octocoral Carijoa sp. (Clavulariidae).

A new bioactive sterol glycoside, 3beta-O-(3',4'-di-O-acetyl-beta-D-arabinopyranosyl)-25xi-cholestane-3beta,5alpha,6beta,26-tetrol-26-acetate) (carijoside A, 1), was isolated from an octocoral identified as Carijoa sp. The structure of glycoside 1 was established by spectroscopic methods and by comparison with spectral data for the other known glycosides. Carijoside A (1) displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils and this compound exhibited moderate cytotoxicity toward DLD-1, P388D1, HL-60, and CCRF-CEM tumor cells.

Cladielloides A and B: new eunicellin-type diterpenoids from an Indonesian octocoral Cladiella sp.

Two new eunicellin-type diterpenoids, cladielloides A (1) and B (2), which were found to possess a 2-hydroxybutyroxy group in their structures, were isolated from an Indonesian octocoral identified as Cladiella sp. The structures of eunicellins 1 and 2 were elucidated by spectroscopic methods. Cladielloide B (2) exhibited moderate cytotoxicity toward CCRF-CEM tumor cells and this compound displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils.

Cytotoxic triterpenoids from the stems of Microtropis japonica.

Bioassay-guided fractionation of a methanol extract obtained from stems of Microtropis japonica led to the isolation of six new ursane-type triterpenoids (1-6) and a new 2,3-seco-oleanane-type triterpenoid (7), together with seven known compounds. The structures of the new compounds were elucidated using spectroscopic data analysis. Among the known compounds isolated, the main component, 8 (ursolic acid), was active for HL60 cells, and its effects on histone hyperacetylation and the inhibition of histone deacetylase (HDAC) activity were investigated.

Antioxidant activities of extracts and main components of Pigeonpea [Cajanus cajan (L.) Millsp.] leaves.

Antioxidant activities of the aqueous and ethanol extracts of pigeonpea [Cajanus cajan (L.) Millsp.] leaves, as well as petroleum ether, ethyl acetate, n-butanol and water fractions and the four main compounds separated from the ethanol extract, i.e. cajaninstilbene acid (3-hydroxy-4-prenylmethoxystilbene-2-carboxylic acid), pinostrobin, vitexin and orientin, were examined by a DPPH radical-scavenging assay and a beta-carotene-linoleic acid test. In the DPPH system, the antioxidant activity of the ethanol extracts was superior to that of the aqueous extracts, with IC(50) values were 242.01 and 404.91 microg/mL, respectively. Among the four fractions, the ethyl acetate one showed the highest scavenging activity, with an IC(50) value of 194.98 microg/mL. Cajaninstilbene acid (302.12 microg/mL) and orientin (316.21 microg/mL) showed more efficient radical-scavenging abilities than pinostrobin and vitexin. In the beta-carotene-linoleic acid test, the inhibition ratio (%) of the ethyl acetate fraction (94.13%+/-3.41%) was found to be the highest, being almost equal to the inhibition capacity of the positive control BHT (93.89%+/-1.45%) at 4 mg/mL. Pinostrobin (>500 microg/mL) and vitexin (>500 microg/mL) showed insignificant antioxidant activities compared with cajaninstilbene (321.53 microg/mL) and orientin (444.61 microg/mL). In general, the ethyl acetate fraction of the ethanol extract showed greater activity than the main compounds in both systems, such results might be attributed to the synergistic effects of the components. The antioxidant activities of all the tested samples were concentration-dependent. Based on the results obtained, we can conclude that the pigeonpea leaf extracts may be valuable natural antioxidant sources and are potentially applicable in both medicine and the healthy food industry.

New cytotoxic lupane triterpenes from Perrottetia arisanensis.

Eight new lupane triterpenes, including 7beta-cis-coumaroylbetulinic acid (1), 7beta-trans-coumaroylbetulinic acid (2), 7beta-cis-coumaroyl-3-epi-betulinic acid (3), 7beta-trans-coumaroyl-3-epi-betulinic acid (4), 7beta-cis-coumaroylbetulonic acid (5), 7beta-trans-coumaroylbetulonic acid (6), 7beta-hydroxybetulinaldehyde (7) and 28-norlup-20(29)-ene-3alpha,17beta-diol (8), together with fifteen known compounds were isolated from the bioactive methanol extract of the stems of Perrottetia arisanensis. The structures of the new compounds were elucidated by spectroscopic and HR-ESI-MS analysis. All new compounds were evaluated for their cytotoxicity against six human cancer cell lines. Among them, lupane triterpene coumaroyl esters 1-6 showed moderate cytotoxicity with IC (50) values ranging from 3.75 to 21.29 microM. This is the first report for lupane triterpenes with a phenylpropane moiety substituted at C-7.

New benzoyl glucosides and cytotoxic pterosin sesquiterpenes from Pteris ensiformis Burm.

Three new compounds: 2R,3R-pterosin L 3-O-beta-D-glucopyranoside (1), beta-D-xylopyranosyl(1-->2)-7-O-benzoyl-beta-D-glucopyranoside (2) and 4-O-benzoyl-beta-D-xylo-pyranosyl(1-->2)-7-O-benzoyl-beta-D-glucopyranoside (3), together with nine known compounds, were isolated from the ethyl acetate extract of Pteris ensiformis. 5-[2-Hydroxyethylidene]-2(5H)-furanone (4), which had been synthesized, was isolated from natural sources for the first time. The structures of all isolated compounds were determined on the basis of mass and spectroscopic evidence. Compound 1 and pterosin B (5) show cytotoxicity against HL 60 cells (human leukemia) with the IC(50) values of 3.7 and 8.7 microg/mL, respectively.

New cytotoxic 6-oxygenated 8,9-dihydrofurocoumarins, hedyotiscone A - C, from Hedyotis biflora.

Using the bioactivity-guided fractionation method, three new 6-oxygenated 8,9-dihydrofurocoumarin-type compounds, hedyotiscones A, B, and C were isolated from the methanol extract of Hedyotis biflora together with seven known compounds. The structures of all isolated compounds were determined on the basis of mass and spectroscopic evidence. Compounds, oleanolic acid, and 6'-(beta-sitosteryl-3- O-beta- D-glucopyranosidyl) pentadecanoate showed marginal cytotoxicity against Hep G2 cells (human liver cancer cells) with IC50 values of 14.4, 17.4, 4.9, 8.0, and 9.2 microg/mL, respectively. Ursolic acid showed significant cytotoxicity against MDA-MB-231 cells (human breast carcinoma cells) with an IC50 value of 1.49 microg/mL.