Phenylpropanoid glycosides from Marrubium alysson.

From the aerial parts of Marrubium alysson a new phenylpropanoid glycoside, alyssonoside, and five known glycosides, verbascoside (= acteoside), leucosceptoside A, martynoside, forsythoside B and leucosceptoside B were isolated. On the basis of spectral data, the structure of the new compound was elucidated as beta-(3,4-dihydroxyphenyl)ethyl-O-[alpha-L-rhamnopyranosyl-(1-->3)]-O- [beta-D-apiopyranosyl-(1-->6)]-4-O-feruloyl-beta-D-glucopyra noside.     

Radical scavenging activity of phenylpropanoid glycosides in Caryopteris incana.

In our screening program for antioxidants from traditional drugs and foodstuffs, one new phenylpropanoid glycoside, incanoside, was isolated together with four known phenylpropanoid glycosides, verbascoside, isoverbascoside, phlinoside A, and 6-O-caffeoyl-beta-D-glucose from the whole plant of Caryopteris incana (Thunb.) Miq. On the basis of chemical evidence and spectral analysis data, the structure of incanoside was determined to be 1-O-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranosyl (1-->2)-alpha-L-rhamnopyranosyl(1-->3)-6-O-caffeoyl-beta-D- glucopyranoside. The four phenylpropanoid glycosides exhibited potent radical scavenging activity against DPPH, hydroxyl (.OH), and superoxide anion (O2-.) radicals.     

C-21 steroidal glycosides from the roots of Cynanchum chekiangense and their immunosuppressive activities

Two new C21 steroidal glycosides, chekiangensosides A and B, were isolated from the roots of Cynanchum chekiangense, together with two known compounds. On the basis of chemical evidence and extensive spectroscopic methods, including one-dimensional and two-dimensional NMR, the structures of two new compounds were identified as cynajapogenin A, 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-alpha-L-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside, and glaucogenin A, 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-cymaropyranosyl-(1-->4)-alpha-L-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside, respectively. The two known steroidal glycosides, and were revised. These isolated compounds were tested for their immunological activities in vitro against concanavalin A (Con A)- and lipopolysaccharide (LPS)-induced proliferation of mice splenocytes. Compounds showed immunosuppressive activities in vitro in a dose-dependent manner.     

Synthesis of a benzyl-protected analog of arenarioside, a trisaccharide phenylpropanoid glycoside

A benzyl-protected analog of the phenylpropanoid glycoside arenarioside, (4-benzyloxyphenyl)ethyl alpha-L-rhamnopyranosyl-(1-->3)-4-O-[(E)-3,4-di-O-benzyl-caffeoyl]-[beta-D-xylopyranosyl-(1-->6)]-beta-D-glucopyranoside (22), was synthesized through two different routes from D-glucose. This is the first approach on the synthesis of a trisaccharide phenylpropanoid glycoside, although the benzyl-protecting group in the backbone of the arenarioside analog could not be removed by conventional debenzylation procedures.     

Two new asterosaponins from the antarctic starfish Diplasterias brucei. Structures and cytotoxic activities

Two new asterosaponins, diplasteriosides A and B, with the same oligosaccharide chains beta-D-Fucp-(1-->2)-beta-D-Galp-(1-->4)-[beta-D-Quip-(1-->2)]-beta-D-Quip-(1-->3)-beta-D-Quip-(1-->, linked to C6 of known genins, 3-O-sulfates of thornasterols A and B, respectively, were isolated along with the previously known asteriidoside A from the Antarctic starfish Diplasterias brucei. The structures of new compounds were elucidated by spectroscopic methods (mainly 2D NMR and mass spectrometry). The cytotoxicity of isolated asterosaponins against human colon cancer cell line HCT-116, human breast cancer cell line T-47D, and human melanoma cancer cell line RPMI-7951 was investigated.     

Physocalycoside,a new phenylethanoid glycoside from Phlomis physocalyx Hub.-Mor

A new phenylethanoid tetraglycoside, physocalycoside (2), was isolated from the aerial parts of Phlomis physocalyx. Its structure was identified as 3-hydroxy-4-methoxy-beta-phenylethoxy-O-[alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)]-4-O-feruloyl-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside, on the basis of spectroscopic evidence. In addition, one known iridoid glucoside, lamiide (1) and five known phenylethanoid glycosides, wiedemannioside C (3), verbascoside (= acteoside) (4), leucosceptoside A (5), martynoside (6), and forsythoside B (7) were also characterized. Compounds 2-7 demonstrated radical scavenging properties towards the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.     

Antioxidative phenylpropanoids from berries of Pimenta dioica

A phenylpropanoid, threo-3-chloro-1-(4-hydroxy-3-methoxyphenyl)propane-1,2-diol, was isolated from the berries of Pimenta dioica together with five known compounds, eugenol, 4-hydroxy-3-methoxycinnamaldehyde, 3,4-dimethoxycinnamaldehyde, vanillin and 3-(4-hydroxy-3-methoxyphenyl)propane-1,2-diol. In addition, the stereochemistry of 3-(4-hydroxy-3-methoxyphenyl)propane-1,2-diol was determined. The phenylpropanoids inhibited autoxidation of linoleic acid in a water-alcohol system.     

Saponins from Allium minutiflorum with antifungal activity

Three saponins, named minutoside A (1), minutoside B (2), minutoside C (3), and two known sapogenins, alliogenin and neoagigenin, were isolated from the bulbs of Allium minutiflorum Regel. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry. The structures of the new compounds were identified as (25R)-furost-2alpha,3beta,6beta,22alpha,26-pentaol 3-O-[beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranosyl] 26-O-beta-D-glucopyranoside (1), (25S)-spirostan-2alpha,3beta,6beta-triol 3-O-beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranoside (2), and (25R)-furost-2alpha,3beta,5alpha,6beta,22alpha,26-esaol 3-O-[beta-D-xylopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->4)-O-beta-D-galactopyranosyl] 26-O-beta-D-glucopyranoside (3). The isolated compounds were evaluated for their antimicrobial activity. All the novel saponins showed a significant antifungal activity depending on their concentration and with the following rank: minutoside B>minutoside C>minutoside A. No appreciable antibacterial activity was recorded. The possible role of these saponins in plant-microbe interactions is discussed.     

Cardiac glycosides from Cryptostegia grandiflora

From the leaves of Cryptostegia grandiflora, four new cardiac glycosides oleandrigenin 3-O-beta-glucopyranosyl-(1-->4)-beta-cymaropyranosyl-(1-->4)-beta-digitoxopyranoside, cryptostigmin I, oleandrigenin 3-O-beta-glucopyranosyl-(1-->4)-alpha-rhamnopyranoside, cryptostigmin II, 16-propionylgitoxigenin 3-O-beta-glucopyranosyl-(1-->4)-alpha-rhamnopyranoside, cryptostigmin III and oleandrigenin 3-O-beta-glucopyranosyl-(1-->6)-beta-glucopyranosyl-(1-->4)-beta-cymaropyranosyl-(1-->4)-beta-digitoxopyranoside, cryptostigmin IV have been isolated together with two known cardenolides subalpinosid and 16-O-acetyl-digitalinum verum. The structures of the isolated compounds were verified by means of MS and NMR spectral analyses.     

Unusual new phenylethanoid and phenylpropanoid diglycosides from the leaves of Chloranthus spicatus (Thunb.) Makino

Chloranthus spicatus (Thunb.) Makino (Chloranthaceae) has been used to treat aches, trauma, and bleeding in Traditional Chinese Medicine. Phytochemical investigation of the leaves of this plant led to the isolation an unusual new phenylethanoid diglycoside, spicaoside (1), and a new phenylpropanoid diglycoside, 1-allyl-3-methoxy-4- [apiofuranosyl(1 ⿿ 2)-glucopyranosyloxybenzene] (2), along with two known sesquiterpenoid glycosides, chloranoside A (3) and chloranthalactone E 8-O-β-d-glucopyranoside (4). Their structures were established by spectroscopic means. New compounds 1 and 2 showed moderate tyrosinase inhibitory activities with the IC₅₀ value of 15.4 μM and 29.1 μM. This study represents the first report of glycoside from C. spicatus.     

New chlorogenin hexasaccharide isolated from Agave fourcroydes with cytotoxic and cell cycle inhibitory activities

A new chlorogenin hexasaccharide (1) was isolated from leaves of Agave fourcroydes (Agavaceae). The structure of the new saponin was elucidated as chlorogenin 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside] (1) by spectroscopic analysis and the result of acidic hydrolysis. The new saponin (1) as well as known hexasaccharides (3 and 5) isolated here showed cytotoxicity against HeLa cells, and 1 exhibited a cell cycle inhibitory effect at the G2/M stage at the concentration of 7.5 and 10 microg/mL.     

Triterpenoid saponins and sapogenin lactones from Albizia gummifera

The structures of two new monodesmosidic and bisdesmosidic triterpenoid saponins (1 and 2) and the known compound delta 5-stigmasterol-3-O-beta-D-glucopyranoside (3) as well as two new oleanane type triterpene lactone glycosides 4, 5 and a new sapogenin lactone 6 isolated from the stem bark of Albizia gummifera C.A. Smith (Mimosaceae) have been elucidated as 3-O-?beta-D-glucopyranosyl(1-->2)-[alpha-L-arabinopyranosyl(1-->6) ]-beta-D- glucopyranosyl?-oleanolic acid (1), beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl 3-O-?beta-D-glucopyra-nosyl(1-->2)-[alpha-L-arabinopyrano syl(1-->6)]-beta-D- glucopyranosyl?-oleanolate (2), 3 beta-?O-D-glucopyranosyl-(1-->2)-[O-alpha-L-arabinopyranosyl(1-->6 )] beta-D-glucopyranosyloxy?-machaerinic acid gamma-lactone (4), 3 beta-O-beta-D-glucopyranosiduronic acid (1-->2)-beta-D-glucopyranosyloxy]-machaerinic acid gamma-lactone (5), and A-homo-3a-oxa-5 beta-olean-12-en-3-one-28-oic acid (6), respectively. The complete assignment of the 1H and 13C resonances of 1, 2, 4 and 6 and of the peracetate of 5 were achieved by means of 2D-NMR studies.     

Structure of a lactic acid ether-containing and glycerol phosphate-containing O-polysaccharide from Proteus mirabilis O40

An O-polysaccharide was isolated by mild acid hydrolysis from the lipopolysaccharide of Proteus mirabilis O40 and studied by NMR spectroscopy, including 2D 1H, 1H COSY, TOCSY, ROESY, and 1H, 13C HMQC experiments, along with chemical methods. The polysaccharide was found to contain an ether of GlcNAc with lactic acid and glycerol phosphate in the main chain and to have the following structure: --> 3)-beta-D-GlcpNAc4(R-Lac)-(1 --> 3)-alpha-D-Galp-(1 --> 3)-D-Gro-1-P-(O --> 3)-beta-D-GlcpNAc-(1 --> where D-GlcpNAc4(R-Lac) stands for 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose. This structure is unique among the known structures of the Proteus O-polysaccharides, which is in agreement with the classification of the strain studied into a separate O-serogroup. A serological relatedness of P. mirabilis O40 with some other Proteus strains was revealed and discussed in view of the O-polysaccharide structures.     

Isomartynoside,a phenylpropanoid glycoside from Galeopsis pubescens

The structure of isomartynoside, a new phenylpropanoid glycoside, isolated along with the known martynoside from Galeopsis pubescens, has been elucidated on the basis of chemical and spectral data as 3-hydroxy-4-methoxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(1 → 3)-6-O-feruloyl-β-D-glucopyranoside.     

Phenylpropanoid and iridoid glycosides from Pedicularis striata.

A new phenylpropanoid glycoside, pedicularioside A, and five known glycosides, acteoside, isoacteoside, decaffeoylacteoside, echinacoside and 8-acetylharpagide, were isolated from whole plants of Pedicularis striata. On the basis of spectral and chemical evidence, pedicularioside A was shown to be 1'-O-beta-D-(3,4-dihydroxy-beta-phenyl)-ethyl-4'-O-caffeoyl-beta-D -apiosyl-(1----3')-alpha-L-rhamnosyl-(1----6')-glucopyranosi de.     

Phenylpropanoid and iridoid glycosides from Pedicularis spicata.

One new phenylpropanoid glycoside, pedicularioside H, and five known glycosides, gardoside methyl ester, shanzhiside methyl ester, 5-deoxypulchelloside I, verbascoside and pedicularioside A, were isolated from whole plants of Pedicularis spicata. On the basis of the spectral data, chemical evidence and comparison with authentic samples, pedicularioside H was determined to be 1'-O-beta-D-(3-methoxy-4-hydroxy-beta-phenyl)-ethyl-4'-O-feruloyl- beta-D- apiosyl(1----3')-alpha-L-rhamnosyl-(1----6')-glucopyranoside .     

Chemical constituents isolated from Disporum viridescens leaves and their inhibitory effect on nitric oxide production in BV2 microglial cells

Excessive NO (nitric oxide) has been associated with the pathogenesis of various neurodegenerative diseases including Alzheimer’s disease (AD). In our screening system using LPS-activated BV2 microglial cells, the methanolic extract of Disporum viridescens leaves was found to have significant NO inhibitory activity. Bioactivity-guided isolation yielded a new phenylpropanoid characterized as 4-ally-2,6-dimethoxyphenyl 1-O-β-d-apiofuranosyl (1 → 6)-β-d-glucopyranoside (12) with 21 known compounds from the leaves of D. viridescens. Among them, compounds 2 and 4 significantly inhibited NO production. Thus, we further elucidated the anti-inflammatory mechanism of these lignans. Especially, compound 4 inhibited the expression of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) through the suppression of the MAPK signaling pathway. Taken together, the anti-inflammatory activities of the active constituents isolated from D. viridescens leaves could have therapeutic potential against neurodegenerative diseases.     

Polyhydroxypregnane glycosides from Oxystelma esculentum var. alpini

Three new polyhydroxypregnane glycosides named alpinoside A [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranosyl-(1-->4)-beta-d-thevetopyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside], alpinoside B [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-thevetopyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside], and alpinoside C [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranosyl-(1-->4)-beta-d-oleandropyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside] were isolated from the leaves of Oxystelma esculentum var. alpini. The structure elucidation was accomplished by extensive spectroscopic analysis and acid-catalyzed hydrolysis.     

Structure of the O-specific polysaccharide of Proteus vulgaris O45 containing 3-acetamido-3,6-dideoxy-D-galactose

An O-specific polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Proteus vulgaris O45 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY, H-detected 1H,13C HSQC and HMBC experiments. The following structure of the pentasaccharide repeating unit of the polysaccharide was established:-->6)-alpha-D-GlcpNAc-(1-->4)-alpha-D-GalpNAc-(1-->4)-alpha-D-GalpA-(1-->3)-beta-D-GlcpNAc-(1-->2)-beta-D-Fucp3NAc4Ac-(1-->where Fuc3NAc4Ac is 3-acetamido-4-O-acetyl-3,6-dideoxygalactose. A cross-reactivity of anti-P. vulgaris O45 serum was observed with several other Proteus lipopolysaccharides, which contains Fuc3N derivatives.     

Phenylpropanoid glycosides isolated from Scrophularia scopolii

A new phenylpropanoid glycoside, angoroside A, and a known glycoside, acteoside, were isolated from the roots of Scrophularia scopolii var. scopolii. On the basis of chemical and spectral evidence, angoroside A was shown to be 3,4-dihydroxy-β-phenylethoxy-O-α-l-arabinopyranosyl-(1 → 6)-α-l-rhamnopyranosyl-(1 → 3)-4-O-caffeoyl-β-d-glucopyranoside.