New triterpenoid saponins from <Emphasis Type="Italic">Argania spinosa</Emphasis>

Five new triterpene saponins, arganine L (1), O (2), P (3), Q (4) and R (5), were isolated from the barks of Argania spinosa (L.) Skeels. Arganines L-P and R are bidesmosidic saponins. The structures of 1–5 were elucidated as 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-apiofuranosyl-(1–3)-β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl] bayogenin, and 3-O-[β-d-apiofuranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, respectively, mainly on the basis of their spectroscopic data.     

Diacylglycerol acyltransferase-inhibitory compounds from <Emphasis Type="Italic">Erythrina senegalensis</Emphasis>

Inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT) is proposed to be a drug target for the treatment of obesity and type 2 diabetes. Bioassay-guided fractionation of the CH₂Cl₂-soluble extract of the stem bark of Erythrina senegalensis, using an in vitro DGAT enzyme assay, resulted in the isolation of eight known prenylflavonoids, 8-prenylleutone (1), auriculatin (2), erysenegalensein O (3), erysenegalensein D (4), erysenegalensein N (5), derrone (6), alpinumisoflavone (7), and 6,8-diprenylgenistein (8). Compounds 1, 2–4, 6, and 8 inhibited DGAT activity, with IC₅₀ values ranging from 1.1 ± 0.3 to 15.1 ± 1.1 μg/mL. On the basis of the data obtained, we propose isoflavonoids with isoprenyl groups as a novel class of DGAT inhibitors.     

Monoterpene glycoside and flavonoids from <Emphasis Type="Italic">Blumea lacera</Emphasis>

The dichloromethane extract of air-dried leaves of Blumea lacera (Asteraceae) afforded α-pinene-7β-O-β-d-2,6-diacetylglucopyranoside (1), 5,4′-dihydroxy-6,7,3′-trimethoxyflavone (2), and 3,5,4′-trihydroxy-6,7,3′-trimethoxyflavone (3). Compounds 1–3 showed moderate activity against Candida albicans, low activity against Trichophyton mentagrophytes, and were inactive against Aspergillus niger. Compounds 1 and 3 indicated low activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and were inactive against Bacillus subtilis, while 2 was inactive against all four bacteria tested.     

A new ceramide from <Emphasis Type="Italic">Ramaria botrytis</Emphasis> (Pers.) Ricken

A new ceramide, (2S,2′R,3R,4E,8E)-N-2′-hydroxyoctadecanoyl-2-amino-9-methyl-4,8-heptadecadiene-1,3-diol (1), was isolated together with four known sterols, 5α,6α-epoxy-3β-hydroxy-(22E)-ergosta-8(14),22-dien-7-one (2), ergosterol peroxide (3), cerevisterol (4) and 9α-hydroxycerevisterol (5), from the fruiting bodies of Ramaria botrytis (Pers.) Ricken (Ramariaceae). The structure of the new compound was elucidated based on spectral data.     

Secoiridoid glycosides from the leaves of <Emphasis Type="Italic">Hydrangea macrophylla</Emphasis> subsp. <Emphasis Type="Italic">serrata</Emphasis>

Seven secoiridoid glycosides, secologanin dimethyl acetal (1), n-butyl vogeloside (2), n-butyl epi-vogeloside (3), (7R)-n-butyl morroniside (4), hydrangenoside A (5), hydrangenoside C (6), and hydrangenoside A dimethyl acetal (7), have been isolated from the leaves of Hydrangea macrophylla subsp. serrata (Thunb.) Makino (Saxifragaceae). The structures were elucidated on the basis of spectral data.     

Two new phenolic glycosides from <Emphasis Type="Italic">Syringa reticulata</Emphasis>

Two new phenolic glycosides—3′-O-β-d-glucopyranosysalidroside (1) and cis-echinacoside (2)—together with four known ones—forsythoside B (3), decaffeoylacteoside (4), osmanthuside F (5) and (−)-olivil-4′-O-β-d-glucopyranoside (6)—were isolated from the leaves of Syringa reticulata. Their structures were established on the basis of spectral and chemical data.     

New prenylated flavones from <Emphasis Type="Italic">Artocarpus champeden</Emphasis>, and their antimalarial activity in vitro

Two new prenylated flavones, artocarpones A and B (1 and 2), and seven known isoprenylated flavonoids, artonin A (3), cycloheterophyllin (4), artoindonesianin E (5), artoindonesianin R (6), heterophyllin (7), heteroflavanone C (8), and artoindonesianin A-2 (9), have been isolated from the stem bark of Artocarpus champeden. Their structures were determined by spectroscopic analysis. Among the compounds isolated, 8 had the most potent inhibitory activity against the growth of Plasmodium falciparum 3D7 clone, with an IC₅₀ value of 1 nmol L⁻¹.     

Prenylated xanthones from <Emphasis Type="Italic">Hypericum ascyron</Emphasis>

Three new prenylated xanthones, 1,3,5-trihydroxy-6,7-[2′-(1-methylethenyl)-dihydrofurano]-xanthone (1), 1,3,5-trihydroxy-6,7-[2′-(1-hydroxy-1-methylethyl)-dihydrofurano]-xanthone (2), and 1,3,5-trihydroxy-6-O-prenyl-xanthone (3), together with eight known compounds were isolated from the leaves of Hypericum ascyron. Compound 3 has an O-prenyl moiety, and therefore represents the first reported xanthone to have an O-prenyl moiety from genus Hypericum. The structures of the isolated compounds were established based on spectroscopic data and on a comparison with values for previously identified analogues.     

A new kaempferol trioside from <Emphasis Type="Italic">Solidago altissima</Emphasis> L.

A new kaempferol trioside [kaempferol 3-O-rutinoside 7-O-β-d-apiofuranoside, (1)] was isolated together with nine phenolic compounds, trans-tiliroside (2), caffeic acid (3), chlorogenic acid (4), 3-O-caffeoylquinic acid (5), 4-O-caffeoylquinic acid (6), 3-O-coumaroylquinic acid (7), 4-O-coumaroylquinic acid (8), 3,5-di-O-caffeoylquinic acid (9) and 4,5-dicaffeoylquinic acid (10) from the leaves of Solidago altissima L. The structure elucidations of the compounds were based on the analyses of spectroscopic data.     

Stilbene and dihydrophenanthrene derivatives from <Emphasis Type="Italic">Pholidota chinensis</Emphasis> and their nitric oxide inhibitory and radical-scavenging activities

Two new stilbene derivatives, (E)-2′,3,3′-trihydroxy-5-methoxystilbene (1, Pholidotol C) and (Z)-3,3′-hydroxy-5-methoxystilbene (2, Pholidotol D), were isolated from the air-dried whole plant of Pholidota chinensis Lindl., together with eight known dihydrophenanthrene derivatives, lusianthridin (3), cannabidihydrophenanthrene (4), coelonin (5), hircinol (6), erianthridin (7), 4,5-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (8), eulophiol (9), and 2,4,7-trihydroxy-9,10-dihydrophenanthrene (10), and a benzoxepin derivative bulbophylol B (11). Their inhibitory effects on nitric oxide (NO) production activity and 1,1-diphenyl-2-picrylhydrazil radical-scavenging activity were examined. Among these compounds, 11 exhibited the most potent activity toward NO production inhibition activity and radical-scavenging activity; moreover, 11 reduced inducible nitric oxide synthase mRNA expression.     

Chemical constituents of <Emphasis Type="Italic">Polyalthia parviflora</Emphasis> stem

From the stem of Polyalthia parviflora, four compounds were isolated, including p-hydroxyphenylethyl p-coumarate (1), p-hydroxyphenylethyl ferulate (2), dehydrodiscretamine (3) and (−)-discretamine (4). Complete ¹H and ¹³C NMR assignments were obtained for 1, 3 and 4 for the first time.     

A new flavonol galloylrhamnoside and a new lignan glucoside from the leaves of <Emphasis Type="Italic">Koelreuteria henryi</Emphasis> Dummer

A new flavonol galloylrhamnoside, kaempferol 3-O-(2″,3″-di-O-galloyl)-α-l-rhamnopyranoside, and a new lignan glycoside, hinokinin 7-O-β-d-glucopyranoside were isolated from the leaves of Koelreuteria henryi, along with 18 known compounds, including six flavonol glycosides (3–8), three lignans (9–11), four chlorophyll derivatives (12–15), two steroids (16, 17), and three aromatic compounds (18–20). The structures were determined on the basis of spectral analysis and chemical evidence. The scavenging effect of 1–8 and 20 on the stable free radical 1,1-diphenyl-2-picrylhydrazyl was examined. Compounds 1, 5, 6, and 20 showed more potent activity than that of trolox.     

A new <Emphasis Type="Italic">Erythrina</Emphasis> alkaloid from <Emphasis Type="Italic">Erythrina herbacea</Emphasis>

A new Erythrina alkaloid, 10-hydroxy-11-oxoerysotrine (1), has been isolated from the flowers of Erythrina herbacea together with five known compounds: erytharbine (2), 10,11-dioxoerysotrine (3), erythrartine (4), erysotramidine (5) and erysotrine-N-oxide (6). The structure of the new compound was elucidated on the basis of its spectral data, including 2-D NMR and mass (MS) spectra. The new compound is a rare C-10 oxygenated Erythrina alkaloid. The antioxidant activities of the isolated compounds 1–6 were evaluated by scavenging with peroxynitrite.     

Linckosides M–Q: neuritogenic steroid glycosides from the Okinawan starfish <Emphasis Type="Italic">Linckia laevigata</Emphasis>

Five new steroid glycosides, linckosides M–Q (1–5), and two known related metabolites, mimics and/or enhancers of the neuritogenic activity of nerve growth factor (NGF), have been isolated from the Okinawan blue starfish Linckia laevigata. Their structures, including stereochemistry, were elucidated by spectroscopic methods and chemical derivatization. The most active metabolite linckoside P (4) induced neurite outgrowth in 55% of PC12 cells 6 days after treatment. Linckosides M–O (1–3) were less active, in the range 21 to 32%. The monoglycosides, linckoside Q (5) and the two known metabolites, 6 and 7, were much less active than the bisglycosides. All the metabolites enhanced the neuritogenic activity of a trace amount of NGF, from 11% to 60–99% three days after treatment. These structure–activity relationships suggest the importance of xylose on a side chain, especially at the C-24 carbon branch rather than at the terminal C-26, for NGF-mimic activity.     

Two novel A-<Emphasis Type="Italic">seco</Emphasis>-rearranged lanostane triterpenoids from <Emphasis Type="Italic">Abies sachalinensis</Emphasis>

Further chemical study led to two new A-seco-rearranged lanostane triterpenoid derivatives (1–2) and one known compound Abiesanolide C (3) from the ethyl acetate (EtOAc) soluble fraction of the MeOH extract of Abies sachalinensis needles. The new compounds were identified as 3,4-seco-8-(14→13R)abeo-17,13-friedo-9β-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oic acid and methyl-3,4-seco-8-(14→13R) abeo-17,13-friedo-9β-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oate, respectively. Structural determination of these compounds were carried out by the spectral studies especially by the two digital (2D)-NMR and high-resolution (HR)-MS experiences.     

Constituents of the roots of <Emphasis Type="Italic">Ligularia dentata</Emphasis> Hara

Nine known compounds, butyrospermol (1), lupeol (2), stigmast-4-en-3-one (3), stigmast-4-ene-3,6-dione (4), (+)-methyl abscisate (5), methyl indole-3-carboxylate (6), vanillin (7), methyl (E)-caffeate (8), and methyl (E)-ferulate (9), and two new compounds, methyl (E)-feruloylglycolate (10), and methyl-7,8-dihydro-(S)-7-methoxyferulate (11), have been isolated from the roots of Ligularia dentata Hara (Compositae). The structures were elucidated on the basis of spectral data.     

New phenylpropanoid esters of sucrose from <Emphasis Type="Italic">Polygonum hydropiper</Emphasis> and their antioxidant activity

By various chromatographic methods, two new phenylpropanoid esters of sucrose named hidropiperosides A (1) and B (2), and three known compounds as vanicosides A (3), B (4), and E (5) were isolated from the methanolic extract of the whole plant of Polygonum hydropiper L. (Polygonaceae). Their structures were elucidated by extensive spectroscopic methods including 1D-and 2D-NMR experiments, as well as ESI-MS analysis. All the isolated compounds were tested for their antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay system. Among them, compounds 2 and 3 showed significant antioxidant activity with their SC₅₀ values of 23.4 and 26.7 μg/mL, respectively.     

Assessment of the antibacterial activity of phenylethanoid glycosides from <Emphasis Type="Italic">Phlomis lanceolata</Emphasis> against multiple-drug-resistant strains of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

Three phenylethanoid glycosides, forsythoside B (1), phlinoside C (2) and verbascoside (3), were isolated from the methanol extract of the leaves of Phlomis lanceolata, an Iranian medicinal plant, by reversed-phase preparative high-performance liquid chromatography (HPLC), and the structures of these compounds were elucidated conclusively by ultraviolet (UV), mass spectrometry (MS) and a series of 1D and 2D nuclear magnetic resonance (NMR) analyses. The antibacterial properties of 1–3 against five multi-drug-resistant (MDR) strains of Staphylococcus aureus have been assessed by the rapid and robust microtitre-plate-based serial dilution method. While compounds 1 and 3 showed considerable activities against all five strains, compound 2 was inactive at the test concentrations.     

Inhibitory effects of compounds isolated from fruit of <Emphasis Type="Italic">Juglans mandshurica</Emphasis> on pancreatic lipase

The water extract of Juglans mandshurica fruit has been shown to strongly inhibit pancreatic lipase in vitro in a dose-dependent manner. The extract was observed to inhibit the normal elevation in the level of plasma triacylglycerol in rats 2–4 h after oral administration of a lipid emulsion. Fourteen compounds isolated from J. mandshurica fruit were evaluated for their inhibitory activity against pancreatic lipase. Of these, 1,4,8-trihydroxynaphthalene-1-O-β-d-[6′-O-(3″,4″,5″-trihydroxybenzoyl)]glucopyranoside (1) showed the strongest inhibitory activity.     

Antioxidative activity of the flower of <Emphasis Type="Italic">Torenia fournieri</Emphasis>

The edible flower of Torenia fournieri Linden ex E. Fourn was found to possess potent antioxidative activity in a rat brain homogenate model. Bioassay-guided isolation of the active compounds from a CH₂Cl₂–MeOH (1:1) extract led to the isolation of acteoside (1), luteolin-7-O-β-glucoside (2), apigenin-7-O-α-rhamnosyl-(1→6)-β-glucoside (3), and apigetrin (4).