Trichobisabolins A-H, eight new bisabolane derivatives from the marine-alga-epiphytic fungus Trichoderma asperellum Y6-2.

Eight new bisabolane derivatives, trichobisabolins A-H, along with two known ones, (3R,6R,7R)-1,10-bisaboladien-3-ol (9) and (3R,6R,7S)-1,10-bisaboladien-3,6-diol (10) were isolated from the culture of Trichoderma asperellum Y6-2, obtained from the surface of the marine red alga Chondrus ocellatus. Their structures and relative configurations were identified by interpretation of 1D/2D NMR and MS data. Compounds 1-8 were assayed for inhibiting the growth of some marine-derived organisms, including four marine phytoplankton species, one marine zooplankton species, and five pathogenic bacteria. All of them exhibited inhibition against the marine phytoplanktons with IC50 values ranging from 2.1-78 µg/mL, compounds 4 and 8 showed weak lethality to the marine zooplankton, and none of them had inhibition against the five pathogenic bacteria.

Beneficial Effect of Jojoba Seed Extracts on Hyperglycemia-Induced Oxidative Stress in RINm5f Beta Cells.

Hyperglycemia occurs during diabetes and insulin resistance. It causes oxidative stress by increasing reactive oxygen species (ROS) levels, leading to cellular damage. Polyphenols play a central role in defense against oxidative stress. In our study, we investigated the antioxidant properties of simmondsin, a pure molecule present in jojoba seeds, and of the aqueous extract of jojoba seeds on fructose-induced oxidative stress in RINm5f beta cells. The exposure of RINm5f beta cells to fructose triggered the loss of cell viability (-48%, p < 0.001) and disruption of insulin secretion (p < 0.001) associated with of reactive oxygen species (ROS) production and a modulation of pro-oxidant and antioxidant signaling pathway. Cell pre-treatments with extracts considerably increased cell viability (+86% p < 0.001) for simmondsin and +74% (p < 0.001) for aqueous extract and insulin secretion. The extracts also markedly decreased ROS (-69% (p < 0.001) for simmondsin and -59% (p < 0.001) for aqueous extract) and caspase-3 activation and improved antioxidant defense, inhibiting p22phox and increasing nuclear factor (erythroid-derived 2)-like 2 (Nrf2) levels (+70%, p < 0.001) for aqueous extract. Simmondsin had no impact on Nrf2 levels. The richness and diversity of molecules present in jojoba seed extract makes jojoba a powerful agent to prevent the destruction of RINm5f beta cells induced by hyperglycemia.

Constituents of the Rhizomes of Boesenbergia pandurata and Their Antiausterity Activities against the PANC-1 Human Pancreatic Cancer Line.

Human pancreatic cancer cell lines have a remarkable tolerance to nutrition starvation, which enables them to survive under a tumor microenvironment. The search for agents that preferentially inhibit the survival of cancer cells under low nutrient conditions represents a novel antiausterity strategy in anticancer drug discovery. In this investigation, a methanol extract of the rhizomes of Boesenbergia pandurata showed potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient-deprived conditions, with a PC50 value of 6.6 µg/mL. Phytochemical investigation of this extract led to the isolation of 15 compounds, including eight new cyclohexene chalcones (1-8). The structures of the new compounds were elucidated by NMR spectroscopic data analysis. Among the isolated compounds obtained, isopanduratin A1 (14) and nicolaioidesin C (15) exhibited potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrition-deprived conditions, with PC50 values of 1.0 and 0.84 µM, respectively.

3-O-ß-D-Glucopyranosyltheobroxide from Aerial Parts of Cowpea (Vigna unguiculata).

Theobroxide has been isolated from culture filtrates of Lasiodiplodia theobromae as a potato tuber-inducing compound. In this study, the metabolism of theobroxide was investigated using cowpea as an experimental model and [2H3-7]theobroxide as a substrate for analyzing a metabolite, which revealed that theobroxide applied exogenously to the roots was converted into 3-O-ß-D-glucopyranosyltheobroxide.

A new polyoxygenated cyclohexane and other constituents from Kaempferia rotunda and their cytotoxic activity.

The isolation of secondary metabolites from a methanolic extract of Kaempferia rotunda yielded 12 compounds (1-12), including a new polyoxygenated cyclohexane compound, (-)-3-acetyl-4-benzoyl-1-benzoyloxymethyl-1,6-diepoxycyclohexan-2,3,4,5-tetrol (1). The structures of the isolated compounds were determined based on their spectroscopic data and comparison with references. All of the isolated compounds were tested for their cytotoxic activity against pancreatic (PSN-1) and breast (MDA-MB231) cancer cell lines. Compound 12 showed moderate cytotoxic activity against PSN-1 and MDA-MB231 without showing any cytotoxicity against the normal cell line, TIG-3.

Cyclohexyl-ethanol derivatives from the roots of Incarvillea mairei.

Two new cyclohexyl-ethanol derivatives, incarvmareins A (1) and B (2), together with two known derivatives, 3 and 4, were isolated from the ethanolic extract of the roots of Incarvillea mairei. The structures of the new compounds were elucidated primarily on the basis of analysis of spectroscopic data.

Polyoxygenated cyclohexane derivatives and other constituents from Kaempferia rotunda L.

Methanol extracts of Kaempferia rotunda L. rhizomes yielded seven compounds including six polyoxygenated cyclohexane derivatives identified as (-)-6-acetylzeylenol (1), four acylated derivatives of 1-benzoyloxymethyl-1,6-epoxycyclohexan-2,3,4,5-tetrol (3-6), a Diels-Alder adduct of 3-benzoyl-1-benzoyloxymethylcyclohexa-4,6-dien-2,3-diol (7), and a triacylated derivative of salicin (9). The cyclohexane diepoxide, crotepoxide (8), was also obtained. Spectroscopic methods were used for structure determination. The methanol extract of the rhizomes of K. rotunda and (-)-2-acetyl-4-benzoyl-1-benzoyloxymethyl-1,6-epoxycyclohexan-2,3,4,5-tetrol (2-acetylrotepoxide B; 6), had antifeedant activity against larvae of Spodoptera littoralis. (-)-Zeylenol (2) also showed antifeedant activity, whereas (-)-6-acetylzeylenol (1) was inactive.

Cyclohexanoid protoflavanones from the stem-bark and roots of Ongokea gore.

Phytochemical investigation of root and stem-bark of the West African medicinal plant Ongokea gore resulted in the isolation of four novel flavonoids with an unusual cyclohexyl substituent instead of the common aromatic ring B. The structures of the isolated compounds were elucidated by spectroscopic methods, mainly 1D and 2D NMR, and subsequently, the structures were corroborated by chemical conversion to (-)-(S)-sakuranetin. The absolute configurations, and preferred conformations were determined by NOE experiments and CD measurements.

Lipoxygenase inhibitory constituents from Periploca aphylla.

Bisflavan-3-ols 1 and 2 and norterpenoid 3 have been isolated from the methanolic extract of the whole plant of Periploca aphylla. Their structures have been assigned on the basis of spectroscopic analysis including 1D and 2D NMR techniques. In addition, o-phthalic acid bis(2-ethylnonyl) ester (4), 1,3,6-trihydroxy-2,5-dimethoxyxanthone (5), and (+)-lyoniresinol (6) have been reported for the first time from this species. Compounds 1-3 displayed evident inhibitory potential against the enzyme lipoxygenase in a concentration-dependent fashion with IC(50) values 19.7, 13.5, and 150.1 microM, respectively.

Effects of theobroxide, a natural product, on the level of endogenous jasmonoids.

The natural potato microtuber inducing substance, theobroxide, strongly induces the formation of tuber of potato (Solanum tuberosum L.) and flower bud of morning glory (Pharbitis nil) plants under non-inducing conditions (long days) (Yoshihara et al., 2000). In the present study, theobroxide was evaluated for its effect on the level of endogenous jasmonoids in different tissues of such two plants. An in vitro bioassay using cultures of single-node segments of potato stems was performed with the supplement of theobroxide in the medium. The endogenous jasmonic acid (JA) and its analogue tuberonic acid (TA, 12-hydroxyjasmonic acid) in segments and microtubers were quantitatively analyzed. The increase in the endogenous JA level caused by theobroxide was observed in both segments and microtubers. Endogenous TA was only detected in segments, and the content increased with the concentration of theobroxide. As for morning glory, the whole plant was sprayed with theobroxide for 1 approximately 5 weeks under different photoperiods and endogenous JA in the leaves was quantitatively analyzed. Theobroxide spraying increased the level of endogenous JA in the leaves of the plants grown under both long and short days.

Isolation and structure determination of a benzofuran and a bis-nor-isoprenoid from Aspergillus niger grown on the water soluble fraction of Morinda citrifolia Linn. leaves.

The leaves of Morinda citrifolia, Linn. afforded a new benzofuran and a bis-nor-isoprenoid, blumenol C, hitherto unreported from this source. The structures of these have been elucidated as 5-benzofuran carboxylic acid-6-formyl methyl ester (1) and 4-(3'(R)-hydroxybutyl)-3,5,5, trimethyl-cyclohex-2-en-1-one (2) respectively through spectroscopic studies. The NMR data (including 1D, 2D techniques) and stereochemistry at C-3' of Compound 2 is also being reported for the first time.

[Studies on the chemical components from Sargassum fusiform].

Three compounds have been isolated from Sargassum fusiform collected from nanao island. Based on the spectral data and elemental analysis, they were identified as 2,4-dihydroxy-2,6-trimethyl-delta 1,alpha-cyclohexaneacetic-r-lactone, saringosterol and cedrol.

Ecologically active 2-octanoylcyclohexane-1,3-dione from Philodendron guttiferum.

The novel naturally occurring 2-octanoylcyclohexane-1,3-dione 1 was isolated in its enol form from P. guttiferum (Araceae). Its chemical ecological relevance is discussed. There was mass spectral evidence for the presence of small amounts of the homologous 2-decanoyl and 2-dodecanoyl derivatives.

Four polyoxygenated cyclohexenes from the Chinese tree, Uvaria purpurea.

Two novel polyoxygenated cyclohexenes, 6-methoxyzeylenol (3) and 2-acetoxyzeylenone (4), together with two known compounds, zeylenol (1) and zeylenone (2), were isolated from the heartwood of the Chinese tree, Uvaria purpurea. Zeylenol (1) and zeylenone (2) both showed inhibitory activity toward the root growth of Lactuca sativa. Their structures were established by spectroscopic and chemical methods.

Secondary metabolites from Senecio minutus and Senecio boissieri: a new jacaranone derivative.

Jacaranone (1), the related new dimethoxy derivative 2, and known triterpenoids were isolated from the aerial parts of Senecio minutus. The aerial parts and the rhizomes of Senecio boissieri afforded the furanoeremophilanes 3 and 4 and known triterpenoids.

Two new caffeoyl conjugation from Erigeron breviscapus.

Two new constituents with a novel basic skeleton were isolated from Erigeron breviscapus. On the basis of chemical and spectroscopic evidences, the structures of the new compounds were elucidated as 1R,3R-dihydroxy-4S,5R-dicaffeoyloxy cyclohexane carboxylic acid methyl ester (V), 1,4-dihydroxy-3R,5R-dicaffeoyloxy cyclohexane carboxylic acid methyl ester (VI).

Platanionosides A-C, megastigmane diglycosides from the leaves of Alangium platanifolium.

From the leaves of Alangium platanifolium var. platanifolium collected in Fukuoka Prefecture, Japan, three megastigmane diglycosides (1-3) were isolated, along with two known compounds, benzyl alcohol 7-O-beta-D-(6'-O-beta-D-xylopyranosyl)glucopyranoside and Z-hex-3-en-1-ol 1-O-beta-D-glucopyranoside. The structures of the new compounds, named platanionosides A (1), B (2), and C (3) were elucidated by spectroscopic evidence to be 3S,5R,6R,9R, 7E-megastigma-3,9-diol 3,9-di-O-beta-D-glucopyranoside, 3R,9R, 7E-megastigma-5,7-diene-3,9-diol 3,9-di-O-beta-D-glucopyranoside, and 5R,6S,7E-megastigma-3-on-7-en-9-ol 9-O-beta-D-(6'-O-beta-D-xylopyranosyl)glucopyranoside, respectively.

New polyoxygenated cyclohexenes from Uvaria calamistrata.

Five new polyoxygenated cyclohexenes, named uvacalol A (1), B (2), C (3), D (4) and E (5) were isolated from the roots of Uvaria calamistrata. On the basis of spectral analysis and chemical derivatization, including the preparation of Mosher esters, the structures of compound 1-5 were established as (2R,3S,4R,5S)-2-acetoxyl-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene3,4-diol-3-benzoate, (2R,3S,4R,5S)-2-acetoxyl-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-3,4-diol-4-benzoate, (2R,3S,4R,5S)-5-ethoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-2,3,4-triol-3-benzoate, (2R,3S,4R,5S)-3-methoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-2,3,5-triol and (2R,3S,4R,5S)-2-acetoxyl-1-benzoyloxymethylcyclohex-1(6)-ene-3,4,5-triol-5-benzoate, respectively.

[The structural elucidation of new polyoxygenated cyclohexenes from Uvaria grandiflora].

Four new polyoxygenated cyclohexenes, named uvarigranol A(1), B(2), E(3) and F(4), along with the known zeylenol were obtained from the roots of Uvaria grandiflora Roxb (Annonaceae). Based on spectral and X-ray analysis as well as Mosher methodology, their structures and absolute configuration were established.