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Five new 5β,19-epoxycucurbitane triterpenoids, taikugausins A-E (1-5), together with 5β,19-epoxy-25-methoxycucurbita-6,23-diene-3β,19-diol (6), have been isolated and characterized from the 70 % EtOH extract of the fresh fruits of Momordica charantia. The chemical structures of compounds 1-6 were elucidated on the basis of extensive spectroscopic analyses, especially 2D NMR (HMQC, HMBC, and NOESY) experiments and HRESIMS data. The relationship between NMR chemical shifts and the configuration of C-19 with an OMe group in 5β,19-epoxycucurbitane are described. Among them, compounds 3 and 4 exhibited remarkable anti-inflammatory activities by the inhibition of nitric oxide production at the concentration of 10 µg/mL. In addition, 3 and 4 also showed moderate cytotoxicity against WiDr, Hep G2, MCF-7, and HEp-2 human tumor cell lines.

Eleutherococcus senticosus (Araliaceae ) is a very powerful adaptogenic agent. In the present study, the effects of syringin, an active principle of this herb, on plasma glucose levels in streptozotocin-induced diabetic rats (STZ-diabetic rats) were investigated. Thirty minutes after syringin was intravenously injected into fasting STZ-diabetic rats, plasma glucose levels dose-dependently decreased. In normal rats, syringin at the effective dose (1.0 mg/kg) significantly attenuated the increase in plasma glucose caused by an intravenous glucose challenge. Syringin dose-dependently (0.01 to 10.0 micromol/L) stimulated glucose uptake in soleus muscle isolated from STZ-diabetic rats. Syringin treatment of hepatocytes isolated from STZ-diabetic rats enhanced glycogen synthesis . The ability of syringin to enhance glucose utilization and lower plasma glucose level in rats suffering from insulin deficiency suggest that this chemical may be useful in the treatment of human diabetes.

A new chemical entity, namely kaempferol 3- O-alpha-L-[2-(Z)-p-coumaroyl-4-(E)-p-coumaroyl]rhamnopyranoside (1), and the known kaempferol 3-O-alpha-L-[2,4-di-(E)-p-coumaroyl]rhamnopyranoside (2) have been isolated from the methanolic extract of leaves of Cinnamomum kotoense. Structural elucidation of compounds 1 and 2 were achieved on the basis of spectroscopic analysis. The effects of compounds 1 and 2 on phytohemagglutinin (PHA) stimulated cell proliferation were studied towards human peripheral blood mononuclear cells (PBMC). The results indicated that compounds 1 and 2 suppressed PBMC proliferation induced by PHA with an IC50 value of 5.0 +/- 1.3 and 6.0 +/- 1.5 microM, respectively. Interleukin-2 production in activated PBMC inhibited by compounds 1 and 2 were in a concentration-dependent manner. Therefore, we suggested that compounds 1 and 2 in C. kotoense were likely the growth modulators for PBMC.

ent-16beta-Hydroxybeyeran-19-oic acid ( 1) has potential antihypertensive activity. To obtain novel and more-effective compounds, 1 was incubated with Bacillus megaterium ATCC 14 581 and Aspergillus niger CCRC 32 720. The structures of the metabolites were determined by HR-FAB-MS, 1D- and 2D-NMR spectral data, and enzymatic hydrolysis. Bacillus megaterium hydroxylated and glucosidated 1 to yield ent-7alpha,16beta-dihydroxybeyeran-19-oic acid ( 2), ent-16beta-hydroxybeyeran-19-oic acid alpha- D-glucopyranosyl ester ( 3), and ent-7alpha,16beta-dihydroxybeyeran-19-oic acid alpha- D-glucopyranosyl ester ( 4). Aspergillus niger hydroxylated 1 to yield ent-1beta,7alpha,16beta-trihydroxybeyeran-19-oic acid ( 5) and ent-1beta,7alpha-dihydroxy-16-oxobeyeran-19-oic acid ( 6). Metabolites 3 - 5 were characterized as new compounds. In addition, 2, 3, 5, and 6 were tested for antihypertensive effects, and we found that 5 and 6 were more potent than the parent compound 1.

Isosteviol is a derivative of stevioside, a constituent of Stevia rebaudiana, and is commonly used as a non-caloric sugar substitute in Japan and Brazil. The present study attempted to elucidate the role of potassium (K (+)) channels in the action of isosteviol on intracellular calcium concentrations ([Ca (2+)]i) in cultured vascular smooth muscle (A7r5) cells using the Ca (2+)-sensitive dye Fura-2 as an indicator. The increase of [Ca (2+)]i in A7r5 cells produced by vasopressin (1 micromol/L) or phenylephrine (1 micromol/L) was attenuated by isosteviol from 0.01 micromol/L to 10 micromol/L. The attenuation by isosteviol of the vasopressin- and phenylephrine-induced increase in [Ca (2+)]i was inhibited by glibenclamide, apamin and 4-aminopyridine but not by charybdotoxin. Furthermore, the inhibitory action of isosteviol on [Ca (2+)]i was blocked when A7r5 cells co-treated with glibenclamide and apamin in conjunction with 4-aminopyridine were present. Therefore, not only did the ATP-sensitive potassium (K (ATP)) channel affect the action of isosteviol on [Ca (2+)]i modulation in A7r5 cells, but also those on the small conductance calcium-activated potassium (SK (Ca)) channels and voltage-gated (Kv) channels. However, the blockers of large-conductance Ca (2+)-activated potassium channels failed to modify the inhibitory action of isosteviol on [Ca (2+)]i. The obtained results indicated that a decrease of [Ca (2+)]i in A7r5 cells by isosteviol is mainly mediated by the selective opening of K (ATP) channel or/and SK (Ca) channel. Alteration in the Kv channel also plays a critical role in the inhibitory action of isosteviol.

The yam (Dioscorea batatas Decne) tuber mucilage (YTM) was extracted and partially purified by SDS and heating treatments. This purified YTM exhibited antioxidant activities in a series of in vitro tests, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (half-inhibition concentration, IC 50, was 0.86 mg/mL) and hydroxyl radical (IC 50 was 22 microg/mL) scavenging activity assays, reducing power test, anti-lipid peroxidation and anti-human low density lipoprotein peroxidation tests (IC 50 was 145.46 microg/mL) using butylated hydroxytoluene (BHT), reduced glutathione, or ascorbic acid for comparisons. With electron paramagnetic resonance (EPR) spectrometry for DPPH radical detection, the intensities of the EPR signals were decreased by the increased amounts of YTM added (IC 50 was 1.62 mg/mL). These results suggest that mucilage of yam tuber might play roles as antiradicals and antioxidants.

Breadfruit (Artocarpus communis) is a widely distributed crop in tropical and subtropical regions of the world. It is used in Southeast Asia and India to treat several inflammatory disorders. The aim of this study was to investigate the presence of anti-inflammatory flavonoids in A. communis leaves. Three new geranyl flavonoids, arcommunol C (1), arcommunol D (3), and 5'-geranyl-3,4,2',4'-tetrahydroxychalcone (5), together with four known compounds, prostratol (2), arcommunol E (4), 3'-geranyl-3,4,2',4'-tetrahydroxydihydrochalcone (6), and 3'-geranyl-3,4,2',4'-tetrahydroxychalcone (7), were isolated from the leaves of A. communis. Compound 4 was isolated for the first time from natural sources. The anti-inflammatory activity of the isolated compounds (1-7) was evaluated by determining their inhibitory activity on the production of proinflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophage cells. Compounds 2, 3, and 4 suppressed the LPS-induced production of nitric oxide (NO) in RAW 264.7 cells with IC50 values of 8.13 ± 0.17, 18.45 ± 2.15, and 22.74 ± 1.74 µM, respectively. Furthermore, 2 decreased lipopolysaccharide (LPS)-mediated induction of protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW 264.7 cells. It was also found that 2 suppressed LPS-induced phosphorylation of JNK and p38 mitogen-activated protein kinase (MAPK) signaling.

Biotransformations of ENT-16beta-hydroxybeyeran-19-oic acid ( 1) by Mortierella isabellina produced hydroxylated metabolites. The isolated metabolites included three new compounds, ent-14beta,16beta-dihydroxybeyeran-19-oic acid ( 3), ent-12beta-hydroxy-16-oxobeyeran-19-oic acid ( 4), and ent-7alpha,12beta-dihydroxy-16-oxobeyeran-19-oic acid ( 5), and one known compound, ent-7alpha,16beta-dihydroxybeyeran-19-oic acid ( 2). The structural elucidation was achieved by detailed analysis of LC-MS chromatograms, and MS and NMR spectroscopic data. In this study, M. isabellina hydroxylated the basic skeleton beyeran-19-oic acid at the 7beta-, 12alpha-, and 14alpha-positions, and oxidized the skeleton at the 16-position. All compounds were evaluated with the cell viability assay. The results of the bioassay indicated that MTT formazan exocytosis occurs upon treatment of the cells with 1.

RAPD (random amplified polymorphic DNA) markers were developed to distinguish Anoectochilus formosanus from Anoectochilus koshunensis and their putative hybrids. Morphological differentiation of these two species beyond the flowering period is difficult. RAPD markers provide a rapid and easy tool for identification of the two Anoectochilus species. In the study, forty arbitrary decamer primers were screened, and nineteen species-specific RAPD markers generated from polymerase chain reactions (PCR) with eight random primers were obtained. Nine were specific to A. formosanus and ten to A. koshunensis. Two primers, OPC-08 and OPL-07, produced two markers, one specific to A. formosanus and the other specific to A. koshunensis, which simultaneously appeared in the hybrids pattern. The RAPD markers can be applied both to identification of A. formosanus and A. koshunensis species and to assessment of the extent fo hybridization in hybrids between them. This information facilitates the breeding program process.

Paeoniflorin and 8-debenzoylpaeoniflorin were isolated from the dried root of Paeonia lactiflora Pall. (Ranunculaceae). They produced a significant blood sugar lowering effect in streptozotocin-treated rats and had a maximum effect at 25 min after treatment. This hypoglycemic action was also observed in normoglycemic rats only at 1 mg/kg. The antihyperglycemic activity of 8-debenzoylpaeoniflorin seems lower than that of paeoniflorin. Plasma insulin was not changed in paeoniflorin-treated normoglycemic rats indicating an insulin-independent action. Also, this glucoside reduced the elevation of blood sugar in glucose challenged rats. Increase of glucose utilization by paeoniflorin can thus be considered. There are no previous data showing the hypoglycemic activity of paeoniflorin and/or 8-debenzoylpaeoniflorin in rats.

Three active principles were isolated from the leaf of Melastoma candidum using the screening of hypotensive effects on spontaneously hypertensive rats (SHR). Intravenous injection of castalagin, procyanidin B-2, or helichrysoside into SHR lowered the mean blood pressure in a dose-dependent manner, with helichrysoside being the most potent compound. Plasma noradrenaline (NA) levels, both basal in SHR and elevated in normal rats through cold-stress stimulation, were attenuated by these compounds in a way which was not influenced by adrenalectomy. Decrease of NA release from sympathetic nerves was assumed to be responsible. Moreover, the hypertensive effect of various vasoconstrictors in anesthetized rats was reduced by helichrysoside. The same results were also observed in castalagin or procyanidin B-2 treated animals. The results indicate that the three principles possess the ability to lower blood pressure through a decrease of sympathetic tone as well as due to direct vasodilatation in SHRs.