A new flavone glycoside from the seeds of Shorea robusta

A new flavonoid, 3,7-dihydroxy-8-methoxyflavone 7-O-α- -rhamnopyranosyl-(1→4)-α- -rhamnopyranosyl-(1→6)-β- -glucopyranoside (1), was isolated from the seeds of Shorea robusta.     

Cycloartane saponins from Astragalus peregrinus as modulators of lymphocyte proliferation

From Astragalus peregrinus, four cycloartane-type saponins have been isolated and their structures elucidated by spectral means as 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-β- -glucopyranoside (1), 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-α- -rhamnopyranosyl-(1→4)-β- -glucopyranoside (2), 20(R),24(S)-epoxy-9β,19-cyclolanostane-3β,6α,16β,25-tetrol 3-O-α- -rhamnopyranosyl-(1→2)-β- -glucopyranoside (3) and 20(R),25-epoxy-9β,19-cyclolanostane-3β,6α,16β,24(S)-tetrol (24-O-acetyl)- 3-O-α- -rhamnopyranosyl-(1→2)-(6′-O-acetyl)-β- -glucopyranoside (4). Compounds 2 and 3 showed to stimulate the proliferation of mouse splenocytes and were not significantly cytotoxic.     

Two new furostanol saponins from Tribulus terrestris L.

Two new furostanol glycosides, named tribufurosides I (1) J (2), were isolated from the fruits of Tribulus terrestris L. by a combination of chemical and spectroscopic methods. Its structures were established as 26-O-β-d-glucopyranosyl-(25S)-5α-furost-12-one-2α,3β,22α,26-tetraol-3-O-β-d-glucopyranosyl (1 → 2)-β-d-glucopyranosyl (1 → 4)-β-d-galactopyranoside (1) and 26-O-β-d-glucopyranosyl-(25R)-5α-furost-20(22)-en-12-one-2α,3β,26-triol-3-O-β-d-glucopyranosyl (1 → 4)-β-d-galactopyranoside (2).     

Proanthocyanidins and a phloroglucinol derivative from Rumex acetosa L.

From the ethyl acetate soluble fraction of an acetone–water extract of the aerial parts of Rumex acetosa L. (Polygonaceae), a variety of monomeric flavan-3-ols (catechin, epicatechin, epicatechin-3-O-gallate), A- and B-type procyanidins and propelargonidins (15 dimers, 7 trimers, 2 tetramers) were isolated with 5 so far unknown natural products. Dimers: procyanidin B1, B2, B3, B4, B5, B7, A2, epiafzelechin-(4β→8)-epicatechin, epiafzelechin-(4β→8)-epicatechin-3-O-gallate (new natural product), epiafzelechin-(4β→6)-epicatechin-3-O-gallate (new natural product), epiafzelechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate, B2-3′-O-gallate, B2-3,3′-di-O-gallate, B5-3′-O-gallate, and B5-3,3′-di-O-gallate. Trimers: procyanidin C1, epiafzelechin-(4β→8)-epicatechin-(4β→8)-epicatechin (new natural product), epicatechin-(4β→8)-epicatechin-(4β→8)-catechin, cinnamtannin B1, cinnamtannin B1-3-O-gallate (new natural product), tentatively epicatechin-(2β→7, 4β→8)-epiafzelechin-(4α→8)-epicatechin (new natural product), and epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate.Tetramers: procyanidin D1 and parameritannin A1. All compounds were elucidated by ESI-MS, CD spectra, 1D- and 2D-NMR experiments as free phenols or peracetylated derivatives and, in part, after partial acid-catalysed degradation with phloroglucinol.A more abundant proanthocyanidin polymer was also isolated, purified and its chemical composition studied by ¹³C NMR.In addition a so far unknown phloroglucinolglycoside (1-O-β-d-(2,4-dihydroxy-6-methoxyphenyl)-6-O-(4-hydroxy-3,5-dimethoxybenzoyl)-glucopyranoside) was isolated.     

A new flavonoid from the aerial part of Thalictrum atriplex

A new flavone glycoside, identified as kaempferol 3-O-[3′″-acetyl-α- -arabinopyranosyl-(1′″–6″)]-β- -glucopyranoside (1), has been isolated from the aerial part of Thalictrum atriplex.     

In vivo hypoglycemic effects of phenolics from the root bark of Morus alba

Moracin M (1), Steppogenin-4′-O-β-D-glucosiade (2), Mullberroside A (3) were isolated from the root bark of Morus alba L. and identified by spectral evidence. Compounds 1, 2 and 3 were studied in hypoglycemic effects on alloxan-diabetic mice. The results showed that compounds 1, 2 and 3 all produced hypoglycemic effects. The compound 2 in a dose of 50 mg/kg exerted significant effect (p < 0.05), 2 and 3 in a dose of 100 mg/kg exerted obviously effect (p < 0.01). Meantime, the compound 1 in a dose of 100 mg/kg can make the fasting blood glucose level have decreasing tendency.     

A new iridoid from Adenosma caeruleum R. Br.

A new iridoid glycoside, adenosmoside (1), together with five known phenylpropanoids, crenatoside, verbascoside, cistanoside F, campneoside I, and campneoside II and two known flavonoids, apigenin 7-O-β-d-glucuronopyranoside and apigenin 7-O-β-d-glucopyranoside, were isolated from the aerial parts of Adenosma caeruleum R. Br. Their structures were elucidated by spectral evidence.     

Cyclisation of farnesyl pyrophosphate into sesquiterpenoids in ginger rhizomes (Zingiber officinale)

The atomic ratios (¹⁴C/³H) obtained in ar-curcumene, α-zingiberene, β-bisabolene obtained from the essential oil of rhizomes of Zingiber officinale which were fed with [2-¹⁴C, 2-³H₂], [2-¹⁴C, 4R-³H₁] and [2-¹⁴C, 5-³H₂]mevalonic acid and [1-³H₂]farnesylpyrophosphate (FPP) revealed that (a) (2E,6E)-isomer of FPP is isomerised to (2Z,6E)-isomer without loss of epimeric hydrogen that means without a redox process; (b) (2Z,6E)-FPP is cyclised to bisabolyl cation which is the penultimate precursor of α-zingiberene, ar-curcumene and β-bisabolene; and (c) two 1,2-hydrogen shifts take place during the formation of α-zingiberene whereas one 1,2 shift has been observed during the formation of ar-curcumene.     

Phytochemical and antifungal studies on Terminalia mollis and Terminalia brachystemma

Phytochemical investigation of the stem bark of Terminalia mollis afforded friedelin (1), catechin with epicatechin (2), gallocatechin with epigallocatechin (3) and 3-O-methylellagic acid 4'-O-α-rhamnopyranoside (4). Arjunolic acid with 2α, 3β, 23-trihydroxy-urs-12-en-28-oic acid (5), 2α-hydroxyursolic acid (6), gallic acid (7), chebulanin (8) and 2'-O-galloylvitexin (9) were isolated from the leaf. Chebulanin (8), betulinic acid (10), ursolic acid (11), catechin (12), isoorientin (13), orientin (14), isovitexin (15) and punicalagin (16) were isolated from Terminalia brachystemma leaf. The first full unambiguous NMR assignments for (4) and (8), and revised assignments for (9), are reported. Compound (16) showed good activity against three Candida species.     

A new biflavonoid from Daphniphyllum angustifolium Hutch

An investigation of the flavonoids in Daphniphyllum angustifolium Hutch. resulted in the identification of a new biflavonoid, 5,7,4′-trihydroxyflavan (2α→O→7, 4α→8) kaempferol (1), together with five known flavonoids. Their structures were determined by spectroscopic method.     

A new cytotoxic casbane diterpene from Euphorbia pekinensis

A new cytotoxic casbane diterpene, named pekinenal, was isolated from the roots of Euphorbia pekinensis. Its structure was elucidated as 5α-hydroxy-1βH,2αH-casba-3Z,7E,11E-triene-18-al by a combination of 1D- and 2D-NMR techniques and confirmed by X-ray crystallography. Pekinenal showed cytotoxic activity against all four human cancer cell lines tested.     

An anti-inflammatory and immunomodulatory polysaccharide from Orbignya phalerata

A polysaccharide, a glucan with mean M_r of 1.0×10⁶ (MP1), was isolated from the mesocarp of fruits of Orbignya phalerata. Chemical and spectroscopic studies indicated that MP1 has a highly branched glucan type structure composed of α-(1→4) linked -glucopyranose residues with (3→4), (4→6), and with (3→6) branching points. MP1 enhanced phagocytosis in vivo and exhibited anti-inflammatory activity.     

Two new flavonoids from Retama raetam

Two new flavones were isolated from the aerial parts of Retama raetam subsp. raetam. Their structures were established as luteolin 4′-O-neohesperidoside (1) and 5,4′-dihydroxy-(3″,4″-dihydro-3″,4″-dihydroxy)-2″,2″-dimethylpyrano-(5″,6″:7,8)-flavone (2) by means of spectroscopic methods. Also present was ephedroidin (4′,5,7-trihydroxy-8-(2-hydroxy-3-butenyl)-flavone).     

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 diglycosyl megastigmane from Carallia brachiata

A new megastigmane diglycoside was isolated from the leaves of Carallia brachiata. The structure was determined by spectroscopic methods as 3-hydroxy-5,6-epoxy-beta-ionol -3-O-beta-apiofuranosyl-(1-->6)-beta-glucopyranoside (1). Additionally, 29 known compounds consisting of two megastigmanes, one 1,2-dithiolane derivative, seven aromatic compounds, five condensed tannins, 12 flavonoids, and two glyceroglycolipids were isolated and identified.     

A new chlorosesquiterpene lactone from Ambrosia maritima

A new chloro-pseudoguaianolide-type sesquiterpene lactone, 11β-hydroxy-13-chloro-11,13-dihydrohymenin (1), was isolated from the Egyptian medicinal plant Ambrosia maritima. The structure was determined by spectroscopic methods, particularly high-resolution ¹H, ¹³C-NMR and 2D ¹H–¹H and ¹H–¹³C COSY NMR analysis.     

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.     

A new ent-kaurane diterpenoid from Rabdosia pseudo-irrorata

A new kaurenoid, ent-3β,7α,14β-trihydroxykaur-16-ene-12,15-dione (1), named pseurata G, was isolated from the ethanol extract of the whole plant of Rabdosia pseudo-irrorata.     

Lignin fragments rich in detached side-chain structures found in water-soluble LCC

The content of the glyceraldehyde-2-aryl ether-type structure in water-soluble lignin–carbohydrate complex (LCC) fractions, which were obtained from Japanese cedar and birch residual wood meal after milled wood lignin isolation, was determined by ozonation. Quite high amounts of the glyceraldehyde-2-aryl ether-type structure were found in water-soluble LCC fractions of both species; about 3–5 times higher than those of other fractions. This result, as well as the high content of the β-1 structure in these fractions shown in our previous reports, suggest that lignin in these fractions has the characteristics of endwise-type lignin, because the glyceraldehyde-2-aryl ether-type structure and β-1 structure are typical characteristics of this type of lignin fraction. These results are in good agreement with the generally accepted hypothesis that the glyceraldehyde-2-aryl ether-type structure and β-1 structure are generated at the same time by a radical coupling reaction. The results also indicated that these two structures are present in close proximity in the lignin.     

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.