Bioactive constituents from Chinese natural medicines. XXVIII. Chemical structures of acyclic alcohol glycosides from the roots of Rhodiola crenulata

Five new glycosides, creosides I, II, III, IV, and V, were isolated from the methanolic extract of the roots of Rhodiola crenulata, together with 21 known compounds. The chemical structures of new constituents were elucidated on the basis of chemical and physicochemical evidence.     

Bioactive saponins and glycosides. XXVII. Structures of new cucurbitane-type triterpene glycosides and antiallergic constituents from Citrullus colocynthis

The methanolic extract from the fruit of Citrullus colocynthis showed an inhibitory effect on ear passive cutaneous anaphylaxis reactions as a type I allergic model in mice. From the methanolic extract, two new cucurbitane-type triterpene glycosides, colocynthosides A and B, were isolated together with 17 known constituents. The structures of colocynthosides A and B were elucidated on the basis of chemical and physicochemical evidence. In addition, the principal cucurbitane-type triterpene glycoside, cucurbitacin E 2-O-beta-D-glucopyranoside, and its aglycon, cucurbitacin E, exhibited the antiallergic activity at a dose of 100 and 1.25 mg/kg, p.o., respectively.     

Chemical structures and hepatoprotective effects of constituents from the leaves of Salacia chinensis

The methanolic extract from the leaves of Salacia chinensis collected in Thailand was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, eight new glycosides, named foliachinenosides E, F, G, H, and I, and foliasalaciosides J, K and L, were isolated together with 26 known constituents. The structures of new glycosides were determined on the basis of physicochemical and chemical evidence. In addition, the hepatoprotective effects of the isolated compounds on D-galactosamine-induced cytotoxicity were examined. Among them, lignans, eleutheroside E? and 7R,8S-dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucopyranoside, were found to show the protective effects [inhibition (%) 41.4 ± 3.6 (p < 0.01), 45.5 ± 2.7 (p < 0.01) at 100 μM, respectively].     

Inhibitors of nitric oxide production from the flowers of Angelica furcijuga: structures of hyuganosides IV and V

The methanolic extract from the flowers of Angelica furcijuga KITAGAWA was found to inhibit nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages. From the methanolic extract, two new glycosides, hyuganosides IV and V, were isolated together with 28 known constituents. The structures of the new constituents were determined on the basis of chemical and physicochemical evidence. Furthermore, the inhibitory effects of 11 coumarin constituents on nitric oxide production were examined. Among them, 3'-angeloyl-cis-khellactone (IC(50)=82 microM), (S)-(-)-oxypeucedanin (57 microM), imperatorin (60 microM), isoepoxypteryxin (53 microM), and isopteryxin (8.8 microM) showed inhibitory activity.     

Analysis of phytochemical constituents of Eucalyptus citriodora L. responsible for antifungal activity against post-harvest fungi

In?vitro antifungal activity and phytochemical constituents of essential oil, aqueous, methanol and chloroform extract of Eucalyptus citriodora Hook leaves were investigated. A qualitative phytochemical analysis was performed for the detection of alkaloids, cardiac glycosides, flavonoids, saponins, sterols, tannins and phenols. Methanolic extract holds all identified biochemical constituents except for the tannin. While these biochemical constituents were found to be absent in essential oil, aqueous and chloroform extracts with the exception of sterols, cardiac glycosides and phenols in essential oil and sterols and phenols in aqueous and chloroform extracts. Antimycotic activity of four fractions of E. citriodora was investigated through agar-well diffusion method against four post-harvest fungi, namely, Aspergillus flavus Link ex Gray, Aspergillus fumigatus Fres., Aspergillus nidulans Eidam ex Win and Aspergillus terreus Thom. The results revealed maximum fungal growth inhibition by methanolic extract (14.5%) followed by essential oil (12.9%), chloroform extract (10.15%) and aqueous extract (10%).     

Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3)

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.     

Effects of constituents from the bark of Magnolia obovata on nitric oxide production in lipopolysaccharide-activated macrophages.

The methanolic extract from a Japanese herbal medicine, the bark of Magnolia obovata, was found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages. By bioassay-guided separation, three neolignans (magnolol, honokiol, obovatol) and three sesquiterpenes (alpha-eudesmol, beta-eudesmol, gamma-eudesmol) were obtained as active constituents. A trineolignan (magnolianin), a phenylpropanoid glycoside (syringin), lignan glycosides (liriodendrin, (+)-syringaresinol 4'-O-beta-D-glucopyranoside) and a sesquiterpene (caryophyllene oxide) did not show any activity. On the other hand, sesquiterpene-neolignans (eudesmagnolol, clovanemagnolol, caryolanemagnolol, eudeshonokiol A, eudesobovatol A) showed the strong cytotoxic effects. Active constituents (magnolol, honokiol, obovatol) showed weak inhibition for inducible NO synthase (iNOS) enzyme activity, but potent inhibition of iNOS induction and activation of nuclear factor-kappaB.     

Monoterpene constituents from Cistanche tubulosa--chemical structures of kankanosides A-E and kankanol-

Four new iridoid glycosides, kankanosides A (1), B (2), C (3), and D (4), a chlorinated iridoid, kankanol (5), and an acyclic monoterpene glycoside, kankanoside E (6), were isolated from the methanolic extract of dried stems of Cistanche tubulosa (SCHRENK) R. WIGHT (Orobanchaceae) together with 16 known compounds. The structures of these new compounds (1-6) were determined on the basis of the chemical and physicochemical evidence.     

Medicinal flowers. VIII. Radical scavenging constituents from the flowers of Prunus mume: structure of prunose III

The methanolic extract and its fractions from the fresh flowers of Prunus mume SIEB. et ZUCC. were found to show scavenging effects on 1,1-diphenylpicryl-2-hydrazyl (DPPH) radical and superoxide. The fragrance constituents of P. mume were analyzed by GC-MS and a new polyacylated sucrose, prunose III, was isolated from the ethyl acetate-soluble fraction. The structure of prunose III was determined on the basis of chemical and physicochemical evidence as 4,3',4',6'-tetra-O-acetyl-6-O-p-coumaroylsucrose. In addition, the scavenging effects of the principal constituents on DPPH radical and superoxide were examined.     

Hyaluronidase inhibitors from Keiskea japonica

An extract of Keiskea japonica MIQ. showed an inhibitory effect on hyaluronidase activity. From the extract, four new phenylpropanoids, two new maltol glycosides, two new monoterpene glycosides, and two new phenolic compounds were isolated together with 19 known compounds. Among these constituents, two phenylpropanoids and a flavone glucuronide were revealed as hyaluronidase inhibitors.     

Bioactive constituents from Chinese natural medicines. XVII. constituents with radical scavenging effect and new glucosyloxybenzyl 2-isobutylmalates from Gymnadenia conopsea

The methanol-eluted fraction of the methanolic extract from the tubers of Gymnadenia conopsea was found to show radical scavenging activities for DPPH and super oxide anion (.O2-) radicals. Three new glucosyloxybenzyl 2-isobutylmalates, gymnosides VIII, IX, and X, were isolated from this natural medicine together with 58 known constituents. The stereostructures of gymnosides were elucidated on the basis of chemical and physicochemical evidence. In addition, the phenanthrene and dihydrostilbene constituents showed radical scavenging activities and suggested the following structural requirements on radical scavenging activities; a) phenanthrenes: 1) dihydrogenation at the 9,10-positions enhances the activities, 2) the 1 or 3-p-hydroxybenzyl group enhances the activities; b) dihydrostilbenes: 1) methylation of the 3'-position reduces the activities, 2) the 2- and/or 6-p-hydroxybenzyl groups enhance the activities.     

Medicinal flowers. III. Marigold. (1): hypoglycemic, gastric emptying inhibitory, and gastroprotective principles and new oleanane-type triterpene oligoglycosides, calendasaponins A, B, C, and D, from Egyptian Calendula officinalis.

The methanolic extract and its 1-butanol-soluble fraction from the flowers of Calendula officinalis were found to show a hypoglycemic effect, inhibitory activity of gastric emptying, and gastroprotective effect. From the 1-butanol-soluble fraction, four new triterpene oligoglycosides, calendasaponins A, B, C, and D, were isolated, together with eight known saponins, seven known flavonol glycosides, and a known sesquiterpene glucoside. Their structures were elucidated on the basis of chemical and physicochemical evidence. The principal saponin constituents, glycosides A, B, C, D, and F, exhibited potent inhibitory effects on an increase in serum glucose levels in glucose-loaded rats, gastric emptying in mice, and ethanol- and indomethacin-induced gastric lesions in rats. Some structure-activity relationships are discussed.     

Aromatic constituents from fruit peels of Citrus reticulata

The methanolic extract of fruit peels of Citrus reticulata, purchased from the local market, afforded a new derivative of benzaldehyde, a new coumarin and two known coumarins. The structures of all the isolated compounds were elucidated with the help of the NMR and Mass techniques.     

Water-soluble constituents of coriander

From the water-soluble portion of the methanol extract of coriander (fruit of Coriandrum sativum L.), which has been used as a spice and medicine since antiquity, 33 compounds, including two new monoterpenoids, four new monoterpenoid glycosides, two new monoterpenoid glucoside sulfates and two new aromatic compound glycosides were obtained. Their structures, were clarified by spectral investigation.     

Bioactive constituents from Chinese natural medicines. XX. Inhibitors of antigen-induced degranulation in RBL-2H3 cells from the seeds of Psoralea corylifolia

The ethyl acetate-soluble fraction of the methanolic extract from the seeds of Psoralea corylifolia was found to inhibit the release of beta-hexosaminidase, as a marker of antigen-IgE-induced degranulation in RBL-2H3 cells. Sixteen constituents were isolated from the ethyl acetate-soluble fraction and several constituents, Delta(1),3-hydroxybakuchiol (IC(50) = 49 microM), Delta(3),2-hydroxybakuchiol (69 microM, bavachin (58 microM), and psoralidin (ca. 100 microM), showed inhibitory activities against the antigen-induced degranulation.     

Antiproliferative constituents from Umbelliferae plants VI. New ursane-type saikosaponin analogs from the fruits of Bupleurum rotundifolium

The MeOH extract of the fruits of Bupleurum rotundifolium showed inhibitory activity against human gastric adenocarcinoma (MK-1) cell growth (GI(50): 6.25 microg/ml). From this extract, 10 new ursane-type triterpene glycosides viz. three 3-O-triosides (called rotundifoliosides A, I, and J) of 13beta,28-epoxy-3beta,16alpha-dihydroxyurs-11-ene, two (G and H) of 13beta,28-epoxy-3beta,16alpha,23-trihydroxyurs-11-ene, two (E and F) of 13beta,28-epoxy-3beta,16alpha,21beta-trihydroxyurs-11-ene, two (B and C) of 3beta,11alpha,16alpha,28-tetrahydroxyurs-12-ene, and one (D) of 3beta,11alpha,28-trihydroxy-15alpha,16alpha-epoxyurs-12-ene were isolated in addition to 16 new oleanane-type triterpene glycosides (rotundiosides J-Y), echinocystic acid 3-O-sulfate and 3 known oleanane-type triterpene glycosides (rotundiosides A, F and G). The isolation, structures and antiproliferative activity of the new ursane-type triterpene glycosides against MK-1, human uterus carcinoma (HeLa), and murine melanoma (B16F10) cell lines are described with some comments on the structural requirements for their activity.     

New constituents from the rhizomes of Egyptian Iris germanica L

Chemical investigation of the methanolic extract of the rhizomes of Iris germanica L. (Iridaceae) afforded two new compounds; irigenin S (7) and iriside A (12), together with ten known compounds: stigmasterol (1), a-irone (2), γ-irone (3), 3-hydroxy-5-methoxyacetophenone (4), irilone (5), irisolidone (6), irigenin (8), stigmasterol-3-O-β-D-glucopyranoside (9), irilone 4'-O-β-D-glucopyranoside (10) and iridin (11). Their structures were established by UV, IR, 1D (1H and 13C) and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to mass spectroscopic data and comparison with literature data. The methanolic extract was evaluated for its antimicrobial activity. Both the methanolic extract and the isolated flavonoids were tested for their anti-inflammatory activity.     

Chemical constituents from Sambucus williamsii Hance fruits and hepatoprotective effects in mouse hepatocytes

Chemical investigation of Chinese folk medicine Sambucus williamsii Hance has resulted in the isolation and characterisation of seventeen compounds from the n-BuOH extract of its fruits, including two new phenylethanoid glycosides and fifteen known compounds. Structures of new compounds were elucidated primarily on the basis of their extensive spectroscopic data including 2D NMR. In addition, the n-BuOH extract from the fruits of S. williamsii was found to show a protective effect on D-galactosamine (D-GalN)-induced cytotoxicity in primary cultured mouse hepatocytes. So the hepatoprotective effects of principal constituents from it were tested by MTT assays. The results showed that Compounds 13, 16 and 17 displayed hepatoprotective effects.     

Rhyncosides A-F, phenolic constituents from the Chinese mangrove plant Bruguiera sexangula var. rhynchopetala

Chemical investigation on the stem of a Chinese mangrove plant Bruguiera sexangula var. rhynchopetala (Rhizophoraceae) resulted in the isolation and characterization of four new phenolic glycosides rhyncosides A-D (1-4), and two new lignan derivatives namely rhyncosides E-F (5-6), along with twelve known phenolic constituents. Their structures were determined by extensive spectroscopic data analyses.     

Medicinal flowers. XIV. New acylated oleanane-type triterpene oligoglycosides with antiallergic activity from flower buds of chinese tea plant (Camellia sinensis)

The methanolic extract from the flower buds of Chinese tea plant (Camellia sinensis (L.) O. KUNTZE) was found to inhibit release of beta-hexosaminidase from RBL-2H3 cells. From the methanolic extract, six new acylated oleanane-type triterpene oligoglycosides, floratheasaponins D-I, were isolated together with 21 known compounds including floratheasaponins A-C. The chemical structures of floratheasaponins D-I were elucidated on the basis of chemical and physicochemical evidence. The principal constituents, floratheasaponins A-F, were found to show the inhibitory activity on the release of beta-hexosaminidase from RBL-2H3 cells.