Lanicepines A and B, Sesquiterpenes with Amino Acid-Derived Substituents from the Flowering Aerial Parts of Saussurea laniceps.

Two new guaianolide sesquiterpenes, lanicepines A (1) and B (2), possessing unusual amino acid-derived substituents at C-13, were isolated from the flowering aerial parts of Saussurea laniceps, a traditional herbal medicine also known as "snow lotus". The structures of 1 and 2 were elucidated based on spectroscopic analysis including applications of the modified Mosher's method and Marfey's method as well as ECD calculations. Lanicepine A (1) contains a dihydropyridinone moiety with a carbamoyl and a hydroxymethyl group. This substituent was considered to consist of asparagine and a C4 unit. In contrast, lanicepine B (2) has a substituent that seems to be derived from l-proline and a C4 unit. Lanicepines A (1) and B (2) and two related known sesquiterpenes isolated from the same plant material, 11ß,13-dihydrodesacylcynaropicrin (3) and 11ß,13-dihydrodesacylcynaropicrin 8-O-ß-d-glucoside (4), demonstrated inhibitory activity against IL-1ß production from LPS-stimulated microglial cells.

Acylated neo-clerodane type diterpenoids from the aerial parts of Scutellaria coleifolia Levl. (Lamiaceae).

Twenty new neo-clerodane type diterpenoids, scutefolides G1-S (1-20), were isolated from the 70 % aqueous acetone extract of the aerial parts of Scutellaria coleifolia. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of 1, 2, 7, 8, 14 and 15 were determined by means of the CD exciton chirality method. Compounds 1, 2, 5, 7, 8, 12, 14, 15, 18 and 19 were evaluated for their cytotoxic activities against four human cancer cell lines, and anti-bacterial activities against methicillin-resistant Staphylococcus aureus.

Maackiain is a novel antiallergic compound that suppresses transcriptional upregulation of the histamine H1 receptor and interleukin-4 genes.

Kujin contains antiallergic compounds that inhibit upregulation of histamine H1 receptor (H1R) and interleukin (IL)-4 gene expression. However, the underlying mechanism remains unknown. We sought to identify a Kujin-derived antiallergic compound and investigate its mechanism of action. The H1R and IL-4 mRNA levels were determined by real-time quantitative RT-PCR. To investigate the effects of maackiain in vivo, toluene-2,4-diisocyanate (TDI)-sensitized rats were used as a nasal hypersensitivity animal model. We identified (-)-maackiain as the responsible component. Synthetic maackiain showed stereoselectivity for the suppression of IL-4 gene expression but not for H1R gene expression, suggesting distinct target proteins for transcriptional signaling. (-)-Maackiain inhibited of PKCδ translocation to the Golgi and phosphorylation of Tyr(311) on PKCδ, which led to the suppression of H1R gene transcription. However, (-)-maackiain did not show any antioxidant activity or inhibition of PKCδ enzymatic activity per se. Pretreatment with maackiain alleviated nasal symptoms and suppressed TDI-induced upregulations of H1R and IL-4 gene expressions in TDI-sensitized rats. These data suggest that (-)-maackiain is a novel antiallergic compound that alleviates nasal symptoms in TDI-sensitized allergy model rats through the inhibition of H1R and IL-4 gene expression. The molecular mechanism underlying its suppressive effect for H1R gene expression is mediated by the inhibition of PKCδ activation.

Coleifolides A and B, Two New Sesterterpenoids from the Aerial Parts of Scutellaria coleifolia H.Lév.

Coleifolides A and B (1 and 2), two new sesterterpenoids with a ß-methyl-α,ß-unsaturated-γ-lactone moiety, were isolated from the aerial parts of Scutellaria coleifolia H.Lév. (Lamiaceae), together with three known compounds. Their structures were elucidated by NMR and MS examinations. Coleifolides A and B were concluded to be partially racemic compounds by the HPLC analysis using a chiral column or introduction of chiral derivatizing agents. The absolute configuration of the major isomer was determined by analyses of the CD spectrum as well as NMR data of (R)- and (S)-2-NMA derivatives. Coleifolides A and B are structurally similar to manoalide derivatives, previously isolated from marine sponges, and appear to be the first examples of this type of compounds being isolated from higher plants.

Acylated neo-clerodanes and 19-nor-neo-clerodanes from the aerial parts of Scutellaria coleifolia (Lamiaceae).

Scutefolides A1 and A2, two acylated neo-clerodanes with a 19,18-γ-lactone, scutefolides B1, B2 and C, three 19-nor-neo-clerodanes, together with scutefolides D, E1, E2 and F, four neo-clerodanes, were isolated from the EtOAc-soluble fraction of the aerial parts of Scutellaria coleifolia. Their structures were established on the basis of spectroscopic analysis. The absolute configurations of four of these compounds were elucidated by the CD exciton chirality method. Cytotoxic activities of scutefolides D-F against four cancer cell lines (KB, A549, HeLa, and MCF7) were also evaluated, but they were inactive.

Hypelodins A and B, polyprenylated benzophenones from Hypericum elodeoides.

Two new polyprenylated benzophenones, hypelodins A (1) and B (2), were isolated from the aerial parts of the Chinese medicinal plant Hyperium elodeoides (Choisy). Their structures were elucidated on the basis of spectroscopic evidence. Hypelodin A (1) is a polyprenylated benzophenone having a tetrahydropyrane ring with three prenyl groups and one 4-methyl-1,3-pentadiene moiety, while hypelodin B (2) has a cage-like structure with a 6/6/5/7/6/5 hexacyclic ring system.

Prenylated flavonoids from the stems and leaves of Desmodium caudatum and evaluation of their inhibitory activity against the film-forming growth of Zygosaccharomyces rouxii F51.

In order to provide scientific evidence for the relationship between the traditional usage, stems and leaves of Desmodium caudatum being used for protecting miso from spoilage, and its Japanese name (miso-naoshi), phytochemical study on the stems and leaves of this plant was carried out. Seven new prenylated flavonoids (1-3, 15-18), together with 19 known compounds (4-14, 19-26), were isolated, and the structures of new compounds were elucidated by extensive spectroscopic analyses. The minimum inhibitory concentrations (MICs) of 28 flavonoids, including 17 compounds (1, 2, 4, 5, 7-14, 20-22, 24, 25) isolated in this study and 11 flavonoids (27-37) previously isolated from the roots of this plant, against the film-forming yeast of Zygosaccharomyces rouxii F51 were determined. Fifteen compounds (2, 4, 5, 11, 12, 14, 21, 22, 25, 27, 28, 32-35) inhibited the film-forming growth of Z. rouxii F51 (MIC values, 7.8-62.5 µg/mL), among which 2",2"-dimethylpyran-(5",6":7,8)-5,2'-dihydroxy-4'-methoxy-(2R,3R)-dihydroflavonol (11) demonstrated potent inhibitory activity with an MIC value of 7.8 µg/mL.

Triterpenoids from the fruits of Azadirachta indica (Meliaceae).

Four new triterpenoids, indicalilacols A-D (1-4), were isolated from the MeOH extract of the fruits of Azadirachta indica, including a new 19(10→9ß)abeo-tirucallane derivative, two new tirucallane-type triterpenoids, and a new euphane-type triterpenoid, along with three known tirucallane-type triterpenoids. Their structures were elucidated on the basis of spectroscopic analyses. The absolute configuration of 2 was elucidated by the chemical conversion of 2 into 21-oxo-melianodiol 24,25-acetonide. Compounds 2, 6-8 exhibited moderate cytotoxicity against three human cancer cell lines, including multidrug-resistant (MDR) cancer cells (KB-C2). Although compound 5 was not cytotoxic against any of the tested cancer cell lines, 5 showed cytotoxicity against KB-C2 cells in the presence of 2.5 µM colchicine, suggesting that 5 might have an MDR-reversal effect.

Conjugates of a secoiridoid glucoside with a phenolic glucoside from the flower buds of Lonicera japonica Thunb.

Secoiridoid glucosides, including two conjugates with a phenolic and two conjugates with a nicotinic acid derivative (3 and 4), together with seven known secoiridoid derivatives, were isolated from flower buds of Lonicera japonica. The structures were elucidated by spectroscopic analyses. Anti-influenza activities of six isolated compounds were also evaluated by plaque assay and neuraminidase inhibitory assay.

Rigenolide A, a new secoiridoid glucoside with a cyclobutane skeleton, and three new acylated secoiridoid glucosides from Gentiana rigescens Franch.

Rigenolide A (1), a new secoiridoid glucoside with a cyclobutane skeleton and three new acylated secoiridoid glucosides, 2'-(2,3-dihydroxybenzoyl)-gentiopicroside (2), 2'-(2,3-dihydroxybenzoyl)-swertiamarin (3), 3'-(2,3-dihydroxybenzoyl)-sweroside (4), along with two noriridoids (7 and 8) and two known secoiridoid glucosides (5 and 6), were isolated from Gentiana rigescens Franch. The structures of new compounds were elucidated by extensive spectroscopic analyses. The isolated compounds were evaluated for DPPH free-radical scavenging activity.

Structural elucidation and biological fate of two glucuronyl metabolites of pelargonidin 3-O-ß-D-glucopyranoside in rats.

A high proportion of pelargonidin 3-O-ß-D-glucopyranoside (Pg3G) is metabolized to glucuronides and excreted in mammal urine after ingestion of strawberry fruit, suggesting that these metabolites play important functional roles in vivo. The aim of the present study was to elucidate the structures and determine the biological fate of the two dominant metabolites of Pg3G in rats to enable an accurate discussion of the biological properties of anthocyanins. Authentic Pg3G was orally administered to rats. One pelargonidin monoglucuronide and three Pg3G-monoglucuronides (glucuronides of the glucoside) were identified together with intact Pg3G in both blood plasma and urine samples. The structures of the two dominant metabolites were elucidated as pelargonidin 3-O-ß-D-glucuronide (Pg3GlcA) and pelargonidin 3-O-ß-D-glucuronyl-(1→2)-ß-D-glucoside by means of (1)H and (13)C nuclear magnetic resonance spectroscopy and heteronuclear multiple-bond connective spectroscopy. The bioavailability of Pg3G in its intact form was 0.31% of the orally administered dose, and 0.65% was absorbed in the Pg3GlcA form.

Prenylated flavonoids from the roots of Desmodium caudatum and evaluation of their antifungal activity.

Two new prenylated flavonoids (1, 4) and two new prenylated C-methyl-flavonoids (6, 7), together with four known flavonoids (2, 3, 5, 8), were isolated from the roots of Desmodium caudatum. The structures of the new compounds were elucidated by extensive spectroscopic analyses including 1D-, 2D-NMR and MS. The antifungal activities of five compounds (1, 2, 4, 6, 8) as well as nine flavonoids (9-17) previously isolated from this plant against Aspergillus niger, Penicillium sp., Rhizopus sp., and Trichophyton sp. were evaluated. Compound 6 showed potent antifungal activity against Trichophyton sp. with a minimum inhibitory concentration (MIC) value of 1.95 µg/mL.

Sesquiterpene lactone glycosides from the roots of Ferula varia.

Seven new sesquiterpene lactone glycosides (1-7) were isolated from the H2O-soluble fraction from the MeOH extract of the roots of Ferula varia. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of compounds 1 and 2 were determined by modified Mosher's method.

Prenylated flavonoids from Desmodium caudatum and evaluation of their anti-MRSA activity.

Seven prenylated flavonoids and a prenylated chromanochroman derivative, together with eight known flavonoids, were isolated from roots of Desmodium caudatum. The 15 structures were elucidated by extensive spectroscopic analyses. The antibacterial activity of many of other compounds was evaluated against methicillin-resistant Staphylococcus aureus (MRSA: COL and 5) by a disc diffusion method, and the minimum inhibitory concentrations (MICs) to MRSA were determined.

Lignans from Schisandra propinqua with inhibitory effects on lymphocyte proliferation.

Seven new dibenzocyclooctadiene lignans, named propinquain E-K, together with 11 known lignans were isolated from the ethanol extract of the roots of Schisandra propinqua subsp. sinensis. The structures of the new compounds were elucidated by spectroscopic methods, including ¹H- and ¹³C-NMR, 2D-NMR, HR ESI-MS, and CD spectra. Two dibenzocyclooctadienes revealed inhibitory effects on lymphocyte proliferation.

Quantification of phosphatidic acid in foodstuffs using a thin-layer-chromatography-imaging technique.

Apical application of lysophosphatidic acid (LPA), a growth-factor-like phospholipid, was shown to prevent or restore gastrointestinal (GI) disorders, such as diarrhea and stomach ulcer, in experimental animals. Because LPA is formed from phosphatidic acid (PA) by the activity of digestive phospholipase A(2), PA is a potential component for dietary treatment of such GI disorders. Here, we quantified PA contained in 38 foodstuffs and 3 herbs by a thin-layer-chromatography-imaging technique. Vegetables belonging to Brassicaceae, such as cabbage leaves (700 nmol/g of wet weight) and Japanese radish leaves (570 nmol/g), contained higher amounts of PA than other foodstuffs. Amounts of PA in fruits, cereals, and starchy root vegetables were below 300 nmol/g. Animal foodstuffs contained low amounts of PA (<60 nmol/g). Interestingly, leaves of Mallotus japonicas, a Japanese edible herb used for treatment of stomach ulcer, had the highest PA (1410 nmol/g) among those examined. The data shown here will be useful for the development of dietary treatment for a damaged GI tract.

New α-glucosides of caffeoyl quinic acid from the leaves of Moringa oleifera Lam.

Two new caffeoyl quinic acid α-glucosides, together with three known caffeoyl quinic acids and five known flavonoid glucosides, were isolated from the leaves of Moringa oleifera Lam. The structures of the new compounds were elucidated as 4-O-(4'-O-α-D-glucopyranosyl)-caffeoyl quinic acid (1) and 4-O-(3'-O-α-D-glucopyranosyl)-caffeoyl quinic acid (2) by spectroscopic analyses.

Spicachlorantins G-J, new lindenane sesquiterpenoid dimers from the roots of Chloranthus spicatus.

Four new lindenane sesquiterpenoid dimers, spicachlorantins G-J (1-4), were isolated from the roots of Chloranthus spicatus together with seven known compounds, including chloramultilide A, shizukaol B, shizukaol D, shizukaol F, shizukaol P, chlorahololide D, and cycloshizukaol A. The planar structures of the new compounds were established by 1D-, 2D-NMR, and MS analyses. The absolute configurations of these compounds were determined by analyzing rotating Overhauser enhancement and exchange spectroscopy (ROESY) and circular dichroism (CD) spectra.

Dyscusins A-C, three new steroids from the leaves of Dysoxylum cumingianum.

Three new steroids dyscusins A-C (1-3), including a stigmastane-type sterol and two pregnanes, together with two known steroids were isolated from the leaves of Dysoxylum cumingianum (Meliaceae). Their structures were elucidated on the basis of extensive spectroscopic analyses. In a cytotoxicity assay, compound 1 showed ten-fold enhanced cytotoxicity against multi-drug resistant cancer cells (KB-C2) in the presence of 2.5 µM colchicine as compared with the absence of colchicine. This notable finding indicated that 1 possessed a multi-drug resistant reversal effect.

Triterpenes and a triterpene glucoside from Dysoxylum cumingianum.

Six triterpenes and a triterpene glucoside were isolated from the MeOH extract of the leaves of Dysoxylum cumingianum together with three known triterpenes. Their structures were elucidated by extensive spectroscopic analyses. In cytotoxicity assays against three human cancer cell lines, including a multi-drug resistant cancer cell line (KB-C2), compounds 1, 2 and 5 demonstrated significantly enhanced cytotoxicity against KB-C2 cells in the presence of 2.5 µM colchicine, as compared with those in the absence of colchicine. This result suggested that these triterpenes might show some MDR-reversing effects.