Chemical constituents of Thai propolis

Phytochemical investigation on the constituents of Thai propolis led the isolation of a new phenylallylflavanone, (7″S)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-(2S)-pinocembrin (1) and (E)-cinnamyl-(E)-cinnamylidenate (2) from methanolic extract of Thai propolis. Their structures were determined on the basis of extensive NMR spectroscopic analysis. In addition to this, 19 compounds (3–21) belonging to flavonoids and phenolic esters were isolated and identified.     

Two new compounds from transgenic Panax quinquefolium

A new ceramide and a new poly-hydroxyl octadecenoic acid were isolated from transgenic crown galls of Panax quinquefolium. Their structures were elucidated as (2S, 3S, 4R, 20E)-2-[(2′R)-2′-hydroxyl-palmitoyl-amino]-20-hexacosene-1, 3, 4-triol (1) and 12, 13, 15-trihydroxy-9-octadecenoic acid (2) respectively on the basis of spectroscopic and chemical methods.     

Glycosylsphingolipids from Euonymus japonicus Thunb

The stem bark of Euonymus japonicus Thunb. led to the isolation of three new glycosylsphingolipids (1–3), 1-O-[-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl]-(2S,3R,9E)-2-N-[(2R)-hydroxystearoyl]-octadecasphinga-9-ene (euojaposphingoside A, 1), 1-O-[β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyl]-(2S,3R,4R,11E)-2-N-[(2R)-hydroxydocasanoyl]-octadecasphinga-11-ene (euojaposphingoside B, 2), 1-O-[β-D-glucopyranosyl]-2′-O-[β-D-glucopyranosyl]-(2S,3R,4R,11E)-2-N-[(2R)-hydroxytetracosanoyl]-octadecasphinga-11-ene (euojaposphingoside C, 3) along with three known glycosylsphingolipids (4–6), 1-O-[β-D-glucopyranosyl]-(2S,3R,9E)-3-hydroxymethyl-2-N-[(2R)-hydroxynonacosanoyl)-tridecasphinga-9-ene (4), 1-O-[β-D-glucopyranosyl]-(2S,3R,9E,12E)-2-N-[(2R)-hydroxytetracosanoyl] octadecasphinga-9,12–diene (5), 1-O-[β-D-glucopyranosyl]-(2S,3R,5R,9E)-2-N-[tridecanoyl] nonacosasphinga-9-ene (6), lupeol (7), stigmasterol (8), sitosterol (β and α) (9,10) and β-carotene (11). The structure of all the compounds was achieved by spectroscopic and chemical data analysis. The antiplasmodial, antileismanial and cytotoxic activity of all compounds was tested.     

Chemical constituents from endophytic fungus Fusarium oxysporum

A new oxysporidinone analogue (1) and a new 3-hydroxyl-2-piperidinone derivative (2), along with the known compounds (−)-4,6′-anhydrooxysporidinone (3), (+)-fusarinolic acid (4), gibepyrone D (5), beauvercin (6),cerevisterol (7), fusaruside (8), and (2S,2′R,3R,3′E,4E,8E)-1-O-D-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine (9) were isolated from Fusarium oxysporum. Compounds 1-9 were evaluated for cytotoxicity using the MTT method against cancer cell lines, PC-3, PANC-1, and A549. Beauvericin showed cytotoxicity against PC-3, PANC-1, and A549 with IC₅₀ value of 49.5 ± 3.8, 47.2 ± 2.9, and 10.4 ± 1.6 μM, respectively. Beauvericin also exhibited anti-bacterial activity towards methicillin-resistant Staphylococcus aureus (MIC = 3.125 μg/mL) and Bacillus subtilis (MIC = 3.125 μg/mL).     

Three pairs of variecolortide enantiomers from Eurotium sp. with caspase-3 inhibitory activity

7-O-methylvariecolortide A (1), variecolortide B (2), and variecolortide C (3), the rare variecolortides existing in racemic manner, were isolated from an endolichenic fungal strain Eurotium sp. (No. 17-11-8-1). With the chiral HPLC technology, (−)-(S)-7-O-methylvariecolortide A (1a), (+)-(R)-7-O-methylvariecolortide A (1b), (−)-(S)-variecolortide B (2a), (+)-(R)-variecolortide B (2b), (−)-(S)-variecolortide C (3a), and (+)-(R)-variecolortide C (3b) were successfully separated and obtained. Their absolute configurations were firstly assigned by ECD experiment and ECD calculation. According to the relation of isolated compounds, a plausible biosynthetic pathway for variecolortides was proposed. In caspase-3 enzymatic assay, compounds 1–3 showed inhibitory activity, with IC₅₀ values of 1.7, 0.8 and 15.7 μM, respectively.     

Two new cerebrosides from the pollen of Typha angustifolia

Two new cerebrosides, 1-O-(β-d-glucopyranosyloxy)-(2S,3S,4R,8Z)-2-[(2′R)-2′-hydroxytricosanoylamino]-8-nonadecene-3,4-diol (1) and 1-O-(β-d-glucopyranosyloxy)-(2S,3R,4E,8Z)-2-[(2′R)-2′-hydroxynonadecanoylamino]-4,13-nonadecene-3-diol (2), were isolated from the pollen of Typha angustifolia. Their structures were elucidated by chemical and spectral means. This is the first report on the occurrence of cerebroside in Typha (Typhaceae). Compounds 1 and 2 exhibited effect on the proliferation of cultured vascular smooth muscle cell (VSMCs) induced by fatal bovine serum (FBS).     

3, 4-seco-Labdane diterpenoids from the leaves of Callicarpa nudiflora and their inhibitory effects on nitric oxide production

As a part of our ongoing search for bioactive compounds from the leaves of Callicarpa nudiflora that inhibit nitric oxide (NO) production, the 90% EtOH fraction eluted by macroporous resin adsorption was found to show significant inhibitory activity against the production of NO in RAW 264.7 stimulated by lipopolysaccharide (LPS). Bioactivity-guided isolation of the fraction yielded three new bioactive diterpenoids, named ent-3, 4-seco-14-carbonyl-15, 16-epoxy-4(18), 8(17), 13(14)-labdatrien-3-oic acid (1), syn-3, 4-seco-12R-hydroxy-15, 16-epoxy-4(18), 8(17), 13(16), 14(15)-labdatetraen-3-oic acid (2) and syn-3, 4-seco-12S-hydroxy-15, 16-epoxy-4(18), 8(17), 13(16), 14(15)-labdatetraen-3-oic acid (3). Their structures and configurations were elucidated by comprehensive spectroscopic analysis. All the three compounds exhibited potent inhibitory activity on NO production in LPS-activated RAW 264.7 macrophage cells.     

Cytotoxic ceramides and glycerides from the roots of Livistona chinensis

A 70% ethanol extract of the roots of Livistona chinensis has been investigated, led to the isolation of 13 compounds, including a new ceramide, (2S,3S,4R,9Z)-2-[(2R)-2-hydroxytricosanoylamino]-9-octadecene-1,3,4-triol (2), a new glycosyl ceramide, 1-O-β-d-glucopyranosyl-(2S,3S,4R,9Z)-2-[(2R)-2-hydroxydocosanoylamino]-9-octadecene-1,3,4-triol (3), three new monoacylglycerols, 1-(34-hydroxytetratriacontanoyl)-sn-glycerol (9), 1-[nonadeca-(9Z,12Z)-dienoyl]-sn-glycerol (10), and 1-[12-hydroxypentatriaconta-(13E,15Z)-dienoyl]-sn-glycerol (11), a new diacylglycerol, 1-(heptadeca-6Z,9Z-dienoyl)-3-(octadeca-6Z,9Z,12Z-trienoyl)-sn-glycerol (12), as well as a new diacylglycerol aminoglycoside, 1-octadecanoyl-2-nonadecanoyl-3-O-(6-amino-6-deoxy)-β-d-glucopyranosyl-sn-glycerol (13). The structures of new compounds were elucidated, based on spectroscopic, zymologic and chemical methods. Among the compounds tested, compounds 3, 4 and 13 showed significantly antiproliferative effects against the human tumor cell lines (K562, HL-60, HepG2, and CNE-1) with the IC₅₀ of 10–65 μM. To our knowledge, this is first report of the occurrence of ceramides and acylglycerols in the genus Livistona.     

Microbial transformation of ginsenoside-Rg₁ by Absidia coerulea and the reversal activity of the metabolites towards multi-drug resistant tumor cells

Biotransformation of ginsenoside-Rg₁ (1) by the fungus Absidia coerulea AS 3.2462 yielded five metabolites (2? 6). On the basis of spectroscopic data analyses, the metabolites were identified as ginsenoside-F₁ (2), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-D-glucopyranoside (3), 3-oxo-20(S)-protopanaxatriol (4), 3-oxo-7β-hydroxy-20(S)-protopanaxatriol (5), and 3-oxo-7β,15α-dihydroxy-20(S)-protopanaxatriol (6), respectively. Among them, 5 and 6 are new compounds. These results indicated that Absidia coerulea AS 3.2462 could catalyze the specific C-3 dehydrogenation of derivatives of ginsenoside-Rg₁, as well as hydroxylation at the 7β and 15α positions. Metabolites 2, 4 and 5 exhibited moderate reversal activity towards A549/taxol MDR tumor cells in vitro.     

Biotransformation of 20(S)-protopanaxadiol by Aspergillus niger AS 3.1858

The biotransformation of 20(S)-protopanaxadiol (1) by Aspergillus niger AS 3.1858 was conducted. Seven metabolites 26-hydroxyl-20(S)-protopanaxadiol (2); 23, 24-en-25-hydroxyl-20(S)-protopanaxadiol (3); 25, 26-en-20(S)-protopanaxadiol (4); (E)-20, 22-en-25-hydroxyl-20(S)-protopanaxadiol (5); 25, 26-en-24(R)-hydroxyl-20(S)-protopanaxadiol (6); 25, 26-en-24(S)-hydroxyl-20(S)-protopanaxadiol (7); and 23, 24-en-25-ethoxyl-20(S)-protopanaxadiol (8) were afforded. Among them, 6, 7, and 8 are new compounds. The chemical structures of these metabolites were elucidated based on extensive spectral data including 2D NMR and HRMS. In addition, the cytotoxicity of substrate and all transformed products was evaluated by MTT assay using a panel of seven human tumor cell lines (Du-145, Hela, K562, K562/ADR, SH-SY5Y, HepG2, and MCF-7 cells) and one normal cell line Vero.     

A new 7-oxygenated coumarin from Clausena suffruticosa

A new coumarin, 7-[(2′E,6′E)-7′-carboxy-5′(ζ)-hydroxy-3′-methylocta-2′,6′-dienyloxy]-coumarin, was isolated from the leaf of Clausena suffruticosa. Its structure was established by means of spectroscopic data analyses, including mass spectrometry and both 1D and 2D NMR spectroscopy.     

Chromones and coumarins from the dried fructus of Cnidium monnieri

Chemical investigations on the ethanolic extract of the dried fructus of Cnidium monnieri offered three chromones and eight coumarins. Among them, a new chromone and a new coumarin were identified and elucidated as 5,7-dihydroxy-6-[(2Z)-4-(β-d-glucopyranosyl)oxy-3- methylbut-2-enyl]-2-hydroxymethyl-4H-1-benzopyran-4-one (1, hydroxycnidimoside A) and (rel 1′S,2′R)-8-(2,3-epoxy-1-hydroxy-3-methylbutyl)-7-methoxycoumarin (8, hydroxyosthole epoxide), respectively, by extensive analyses of spectroscopic data including 1- and 2-D NMR, MS, UV, OR, IR, and HRMS data. The other known compounds were identified by analyses of spectroscopic data and by comparison with literature reported.     

New clerodane diterpenoids from Casearia sylvestris

Two new clerodane diterpenoids 2β-methoxy-cleroda-3,13-dien-18-carboxy-15,16-olide (1) and 15ξ-methoxy-cleroda-3,12-dien-18-carboxy-15,16-olide (2) and one new nitrogen-containing clerodane diterpenoid 15-oxo-echinophyllin A (3), along with six known compounds, namely, echinophyllin A, (−)-patagonic acid, tyrosol, oplopanone, 4-hydroxy-4-methyl-2-[(1R)-1-(1-methylethyl)-4-oxopentyl]-2-cyclohexen-1-one and 1β,6α-dihydroxy-eudesman-4(15)-ene were isolated from the leaves of Casearia sylvestris. Their structures were determined by extensive NMR techniques.     

A new cerebroside from Gynura divaricata

A new cerebroside, 1-O-β-d-glucopyranosyl-(2S,3S,4R,10E)-2-[(2′R)-2′-hydroxyltricosanoyl-amino]-10-octadecene-1,3,4-triol was isolated from the aerial parts of Gynura divaricata DC.     

Antifungal properties of methanol extract and its active compounds from Brickellia rosmarinifolia Vent

A new isocoumarin, 7-hydroxyl-4-methyl isocoumarine (1), together with three known monoterpenes, (3R, 4R, 6S)-3, 6-dihydroxy-1-menthene (2), (+)-(1R, 3S, 4R, 6S)-6-hydroxymenthol (3) and 4-isopropyl-1-methylcyclohex-2-ene-1, 6-diol (4), was isolated from the methanol extract of Brickellia rosmarinifolia. The structures were determined by spectroscopic means. Compounds 1, 2, 3 and 4 showed antifungal activities against Colletotrichum musae and Peronophythora litchii in vitro.     

Bioactive phenolics from the fruits of Livistona chinensis

This study investigated the antioxidant and cytotoxic activity of the phenolics isolated from the fruits of Livistona chinensis. Four new compounds, 1-{ω-isoferul[6- (4-hydroxybutyl)pentadecanoic acid]}-glycerol (1), E-[6′-(5″-hydroxypentyl)tricosyl]-4-hydroxy-3-methoxycinnamate (2), 2-(3′-hydroxy-5′-methoxyphenyl)-3-hydroxylmethyl-7-methoxy-2,3-dihydrobenzofuran-5- carboxylic acid (3), 7-hydroxy-5,4′-dimethoxy-2-arylbenzofuran (4), together with eleven known phenolics (5-15), were isolated and identified. Among these compounds, 1-4, 5-O-caffeoylshikimic acid (5), caffeic acid (7), and 3-O-caffeoylshikimic acid (8) showed potent antioxidant activity. 1-5, and 8 showed potent antiproliferative activities with IC₅₀ values among 5-150 μM against HepG2 human liver cancer, HL-60 human myeloid leukemia, K562 human myeloid leukemia, and CNE-1 human nasopharyngeal carcinoma cell lines. On the basis of these findings, it could be proposed that the fruits of L. chinensis may serve as attractive mines of powerful anticancer and antioxidant agents for various purposes.     

Dihydroroseoside, a new cyclohexanone glucoside, from the leaves of shirakamba (Betula platyphylla Sukatchev var.japonica Hara)

A new cyclohexanone glucoside (II) and a known cyclohexenone glucoside roseoside [I, (6S, 9S)-6-hydroxy-6-(9--D-glucopyranosyloxy-trans-7-butenyl)-1,5,5-trimethyl-1-cyclohexenone] were isolated from an ethanol extract of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves. The structure ofII was determined to be (6S, 9R)-6-hydroxy-6-(9-O--D-glucopyranosyloxy-trans-7-butenyl)-1, 5,5-trimethyl-1-cyclohexanone by¹H-NMR and¹³C-NMR spectroscopic analyses. It was named dihydroroseoside.     

Diastereomers of lithospermic acid and lithospermic acid B from Monarda fistulosa and Lithospermum erythrorhizon

Monardic acids A (1) and B (2), which are (7R,8R) diastereomers of lithospermic acid (LA) and lithospermic acid B, respectively, were isolated from Monarda fistulosa. A (7S,8R) isomer (3) of LA was also isolated from this plant, and a (7R,8S) isomer (7) of LA was obtained from Lithospermum erythrorhizon. The absolute configuration of 1 was confirmed by analysis of its hydrolysates, 7-epiblechnic acid and 2R-3-(3,4-dihydroxyphenyl)-2-hydroxypropanoic acid. The configuration in the dihydrobenzofuran moieties of 2, 3, and 7 was extrapolated by using the phenylglycine methyl ester method and a Cotton effect at approximately 250–260 nm in their electronic circular dichroism spectra. Diastereomers (1–3 and 7) displayed moderate hyaluronidase inhibitory and histamine release inhibitory activities.     

Constituents of Cynara cardunculus

The isolation of (−)-arctigenin (1) and (−)-arctigenin 4′-glucoside from the seeds of Cynara cardunculus, and of hentriacontane and eicosyldocosanoate from the leaves is reported, along with ¹H- and ¹³C-NMR spectra of 1.