Furostanol saponins and quercetin glycosides from the leaves of Helleborus viridis L

Phytochemical analysis of the polar extracts of the leaves of Helleborus viridis (Ranunculaceae) resulted in the isolation of two new furostanol saponins (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-[6-acetyl-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranoside (1) and (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranoside (2) and three new quercetin glycosides, quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside-7-O-beta-d-glucopyranoside (3), quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (4), and quercetin 3-O-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (5). The structures of the new compounds were determined by spectroscopic analysis, including 2D NMR data and mass spectrometry.     

Bioactive flavonoids and saponins from Climacoptera obtusifolia

Two bidesmosidic saponins were isolated from Climacoptera obtusifolia (Chenopodiaceae) and their structures were determined as gypsogenin 3-O-[beta-D-xylopyranosyl-(1-->3)-beta-D-glucopyranoside]-28-O-{beta-D-glucopyranosyl} ester (1) and hederagenin 3-O-[beta-D-xylopyranosyl-(1-->3)-beta-D-glucopyranoside]-28-O-[beta-D-glucopyranosyl} ester (2), by spectroscopic methods. Two known compounds, isorhamnetin 3-O-beta-D-glucopyranoside (3), and isorhamnetin 3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (4) were also isolated for the first time from this plant. Compounds 1-4 were tested in various immunomodulatory assays. Compound 2 suppressed (92%) the reactive oxygen species (ROS) production on mononuclear cells in luminol-based chemiluminescence (CL) assay at a higher concentration (50 microg/mL). Compounds 3 and 4 demonstrated a strong inhibition on ROS production in the oxidative burst activity of whole blood, neutrophils, and mononuclear cells. Additionally compounds 3 and 4 also suppressed PHA T-cell proliferation with no cytotoxic effects.     

Acetylated flavonol diglucosides from Meconopsis quintuplinervia

Four acetylated flavonol diglucosides, quercetin 3-O-[2'-O-acetyl-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside], quercetin 3-O-[2',6'-O-diacetyl-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside], isorhamnetin 3-O-[2'-O-acetyl-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside], and quercetin 3-O-[2'-O-acetyl-alpha-l-arabinopyranosyl-(1-->6)-beta-d-glucopyranoside], together with five known flavonol glycosides quercetin 3-O-beta-d-glucopyranoside, kaempferol 3-O-beta-d-glucopyranoside, quercetin 3-O-[beta-d-galactopyranosyl-(1-->6)-glucopyranoside], isorhamnetin 3-O-[beta-d-galactopyranosyl-(1-->6)-beta-d-glucopyranoside], and kaempferol 3-O-[beta-d-glucopyranosyl-(1-->2)-beta-d-glucopyranoside] have been isolated from Meconopsis quintuplinervia. Their structures were determined using chemical and spectroscopic methods including HRFABMS, (1)H-(1)H COSY, HSQC and HMBC experiments.     

New flavonoid glycosides from Aconitum naviculare (Brühl) Stapf, a medicinal herb from the trans-Himalayan region of Nepal

Three new flavonoid glycosides, 3-O-[beta-D-glucopyranosyl-(1-->3)-(4-O-trans-p-coumaroyl)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]kaempferol, 3-O-[beta-D-glucopyranosyl-(1-->3)-(4-O-trans-p-coumaroyl)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]quercetin and 7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]quercetin were isolated from the aqueous extract of the aerial parts of Aconitum naviculare. Their structures were elucidated by spectral analysis (HRAPI-TOF MS, 1H, 13C NMR, HMQC, HMBC, DFQ-COSY, ROESY and TOCSY).     

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.     

Triterpenoid saponins from the stem bark of Elattostachys apetala

Six new triterpenoid saponins have been isolated from the stem bark of Elattostachys apetala together with four known triterpenoid saponins. Three of these new compounds are glycosides of a newly described genin, 29-hydroxyhederagenin (1). On the basis of spectral evidence, the structures of the new saponins were concluded to be alpha-hederin 28-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl] ester (2), sapindoside B 28-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl] ester (3), 3-O-beta-D-xylopyranosyl astrantiasaponin VII (4), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranosyl]-29-hydroxyhederagenin (5), 3-O-[alpha-L-arabinopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-glucopyranosyl(1-->2)-[beta-D-glucopyranosyl(1-->6)]-beta-D-glucopyranosyl]-29-hydroxyhederagenin (6), and 3-O-[beta-D-xylopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl]-28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-gluco pyranosyl-(1-->6)]-beta-D-glucopyranosyl]-29-hydroxyhederagenin (7).     

Synthesis and antitumor activity of new D-galactose-containing derivatives of doxorubicin

A general scheme of synthesis of antibiotic doxorubicin derivatives is based on the 13-dimethyl ketal of 14-bromodaunorubicin (4). The interaction of 4 with melibiose (5), lactose (6), 3-methoxy-4-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-4-oxybenzaldehyde (12) or 4-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-4-oxybenzaldehyde (13) by reductive alkylation followed by hydrolysis of the corresponding intermediate bromoketals produced 3'-N-[alpha-D-galactopyranosyl-(1-->6)-O-1-deoxy-D-glucit-1-yl]doxorubicin (7), 3'-N-[beta-D-galactopyranosyl-(1-->4)-O-1-deoxy-D-glucit-1-yl]doxorubicin (8), 3'-N-[3"-methoxy-4"-O-(beta-D-galactopyranosyl)-4"-oxybenzyl]doxorubicin (16), and 3'-N-[4"-O-(beta-D-galactopyranosyl)-4"-oxybenzyl]doxorubicin (17). Cytotoxic and antitumor activity of the synthesized drug candidates compared to the parent doxorubicin was studied using various experimental models, in particular, on mice bearing lymphocyte leukemia P-388 at single and multiple i.v. injection regimens.     

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.     

Nuatigenin-type steroidal saponins from Veronica fuhsii and V. muldtfida

A new nuatigenin-type steroidal saponin, multifidoside (2), was isolated from the aerial parts of Veronica fuhsii and V multifida and its structure was identified as 3-O-([alpha-L-rhamnopyranosyl-(1-->2glu)]-[beta-D-glucopyranosyl-(1-->4rha)-alpha-L-rhamnopyranosyl (1-->4glu)]-beta-D-glucopyranosyl]nuatigenin 26-O-beta-D-glucopyranoside. Additionally, a known steroidal saponoside, aculeatiside A (1), from V. fuhsii, a phenylethanoid glycoside, verpectoside A (3), and a flavon glycoside, isoscutellarein 7-O-(2"-O-6"-O-acetyl-beta-D-allopyranosyl-beta-D-glucopyranoside) (4) from V. multifida were isolated.     

Flavonoids from seeds of Camellia semiserrata Chi. and their estrogenic activity

Two new flavonol glycosides and three known flavonoids were isolated from seeds of Camellia semiserrata Chi. The structures of these new flavonol glycosides were established as kaempferol 3-O-[(2',3',4'-triacetyl)-alpha-L-rhamnopyranosyl(1-->3)(2',4'-diacetyl)-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside] and kaempferol 3-O-[(3',4'-diacetyl)-alpha-L-rhamnopyranosyl(1-->3)(2',4'-diacetyl)-alpha-L-rhamnopyranosyl(1-->6)-beta-D-glucopyranoside] by spectroscopic methods. The estrogenic activity of these compounds was investigated by a recombinant yeast screening assay.     

Two triacylated and tetraglucosylated anthocyanins from Ipomoea asarifolia flowers

Two triacylated and tetraglucosylated anthocyanins derived from cyanidin were isolated from the flowers of Ipomoea asarifolia and their structures elucidated using chemical, GC, MS and NMR methods (1H and 13C, TOCSY-1D, DQF-COSY, DIFFNOE and HMBC). These complex pigments were found to consist of cyanidin 3-O-[2-O-(6-O-E-caffeoyl-beta-D-glucopyranosyl)]-[6-O-[4-O-(6-O-E-3,5-dihydroxycinnamoyl-beta-D-glucopyranosyl)-E-caffeoyl]-beta-D-glucopyranosyl]-5-O-beta-D-glucopyranoside and cyanidin 3-O-[2-O-(6-O-E-p-coumaroyl-beta-D-glucopyranosyl)]-[6-O-[4-O-(6-O-E-p-coumaroyl-beta-D-glucopyranosyl)-E-caffeoyl]-beta-D-glucopyranosyl]-5-O-beta-D-glucopyranoside.     

Three new benzophenone glycosides with MAO-A inhibitory activity from Hypericum thasium Griseb.

Purification of n-BuOH fraction from 80% ethanol extract of Hypericum thasium Griseb. resulted in the isolation of three new compounds 3′,4,5′-trihydroxy-6-methoxy-2-O-α-l-arabinosylbenzophenone (1), 3′,4,5′,6-tetrahydroxy-2-O-α-l-arabinosylbenzophenone (2), and 3′,4-dihydroxy-5′-methoxy-2-O-α-l-arabinosyl-6-O-β-d-xylosylbenzophenone (3) along with a known flavonoid glycoside quercetin-3-O-α-l-arabinofuranoside (4). The structures of the new compounds were elucidated by 1D and 2D NMR analysis as well as HRESIMS. The isolated compounds (1–4), as well as quercetin, and kaempferol previously isolated from EtOAc fraction were screened against MAO-A inhibitory activity. When tested against the MAO-A quercetin and kaempferol displayed IC₅₀ values of 19.6, and 17.5 μM, respectively. The IC₅₀ values for MAO-A inhibition by compounds (1–4) were 310.3, 111.2, 726.0, and 534.1 μM, respectively. Standard inhibitor (clorgyline) exhibited MAO-A inhibition with an IC₅₀ value of 0.5 μM.     

Bioactive saponins from Astragalus suberi L. growing in Yemen

From the aerial parts of Astragalus suberi L., Fabaceae, seven saponins were isolated. Based on spectral data (IR, 1H and 13C NMR and HR-FABMS), the structures were established as 3-O-(beta-D-glucopyranosyl)-soyasapogenol B (1); 3-O-(beta-D-glucuronopyranosyl)-soyasapogenol B (2); 3-O-[beta-D-galactopyranosyl (1-->2)-beta-D-glucopyranosyl]-soyasapogenol B (3); 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucopyranosyl]-soyasapogenol B (4); 3-O-[beta-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucopyranosyl]-11-hydroxy-soyasapogenol B (5); 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucuronopyranosyl]-soyasapogenol B (6) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-galactopyranosyl (1-->2)-beta-D-glucuronopyranosyl]-complogenin (7). The isolated saponins exhibited antibacterial activities against Gram-positive and Gram-negative bacteria with minimum inhibitory concentration values >100 microg/ml, antifungal activity against all the strains tested with minimum fungicidal concentration values between 25 and 50 microg/ml and inhibited the growth of Hep-2 (human carcinoma of larynx), with IC50 values between 50 microg/ml (compounds 5-7) and 100 microg/ml (compounds 1-4), and Hela (human carcinoma of cervix) cell lines in culture with different IC50 values [74 (compound 7), 98 (compound 5) and 180 microg/ml (compounds 1-4 and 6)].     

Neolignan glycosides from Symplocos caudata

A phytochemical investigation of the roots of Symplocos caudata Wall (Symplocaceae) resulted in isolation and characterization of four optical isomers of a neolignan glycoside (1-4), a lignan lactone glycoside (5), a phenylpropanoid glycoside (6), as well as two known compounds (7, 8). Their structures were elucidated as (7S,8S)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (1), (7R,8R)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (2), (7R,8S)-erythro-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (3), (7S,8R)-erythro-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (4), 8R,8'R-matairesinol-4-O-beta-d-xylopyranosyl-(1-->2)-O-beta-d-glucopyranoside (5), 1-O-[beta-d-xylopyranosyl-(1-->6)-O-beta-d-glucopyranosyl]-2,6-dimethoxy-4-propenyl-phenol (6), matairesinoside (7), and (R)-1-O-(beta-d-glucopyranosyl)-2-[2-methoxy-4-(omega-hydroxypropyl)-phenoxyl]-propan-3-ol (8) on the basis of spectroscopic data (1D and 2D NMR, MS and CD) and chemical evidence.     

Astersedifolioside A-C, three new oleane-type saponins with antiproliferative activity

A phytochemical analysis of Aster sedifolius has led to the isolation of three novel triterpenoid saponins, based on an oleane-type skeleton and named astersedifolioside A (1), B (2) and C (3). On the basis of chemical, and 2D NMR and mass spectrometry data, the structures of the new compounds were elucidated as 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (1), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (2) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (3). The isolated compounds showed antiproliferative effect in KiMol, a transformed thyroid cell line.     

In vivo anti-inflammatory activity of saponins from Bupleurum rotundifolium

Seven oleanane-type triterpene saponins were isolated from the methanolic extract of the aerial parts of Bupleurum rotundifolium. They were identified on the basis of their spectral data as 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid (saponin 1), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-fucopyranosyl] 11-methoxy-primulagenin A (saponin 2), rotundioside E (saponin 3), rotundioside F (saponin 4), 3beta-sulfate, 28-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] ester of primulagenin A (saponin 5), rotundioside C (saponin 6) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-fucopyranosyl] 11-methoxy-16beta,21alpha,28-trihydroxyolean-12-ene (saponin 7). All these saponins proved to be effective against TPA-induced ear edema in mice. Their ID50 were determined to be 248, 288, 128, 99 and 297 nmol/ear for saponin 1, 2, 3, 4 and 6, respectively. Saponins 3 and 6 were also active on a TPA multiple-dose model of skin chronic inflammation.     

A malonylated anthocyanin and flavonols in blue Meconopsis flowers

The structures of the major anthocyanin and two flavonols from the blue flowers of Meconopsis were identified by NMR spectroscopy as being cyanidin 3-O-[(6-O-malonyl-2-O-B-D-xylopyranosyl)-beta-D-glucopyranoside]-7-O-beta-D-glucopyranoside, kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-glucopyranoside and kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside respectively.     

Acetylated glucuronide triterpene bidesmosidic saponins from Symplocos glomerata

Nine new bidesmosidic 3-O-glucuronide oleanane triterpenoid saponins were isolated from the stem bark of Symplocos glomerata King along with two known saponins, salsoloside C and copteroside E, and two major lignans, (-)-pinoresinol and (-)-pinoresinol-4'-O-beta-D-glucopyranoside. The structures of the new saponins were established using one- and two-dimensional NMR spectroscopy and mass spectrometry as, 3-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl(1-->4)-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl (1-->4)-[2,3-O-diacetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl(1-->4)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl (1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-xylopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[alpha-L-arabinofuranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, and 3beta-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-morolic acid. The EtOH and EtOAc extracts of the stem bark showed no cytotoxic activity. At a concentration of 370 microg/ml, the saponin mixture showed haemolytic activity and caused 50% haemolysis of a 10% suspension of sheep erythrocytes.     

Non-phenolic antioxidant compounds from Buddleja asiatica

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1-diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 microg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-beta-D-glucopyranosyl-2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3 beta,23,28-triol (2), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3,23,28-triol (3), and 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl-acid-olean-11,13(18)-diene-3 beta,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.     

Chemoenzymatic synthesis of the 3-sulfated Lewisa pentasaccharide

The sulfated pentasaccharide benzyl O-(3-O-sulfo-beta-D-galactopyranosyl)-(1-->3)-O-[(alpha-L-fucopyranosyl)-(1-->4)]-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1-->3)-O-(beta-D-galactopyranosyl)-(1-->4)-O-beta-D-glucopyranoside sodium salt was synthesized using a chemo-enzymatic approach. Lacto-N-tetraose, obtained from two disaccharides [4-methoxybenzyl O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->3)-4,6-O-benzylidene-2-deoxy-2-phtalimido-beta-D-glucopyranoside and benzyl 2,6-di-O-acetyl-beta-D-galactopyranosyl-(1-->4)-2,3,6-tri-O-acetyl-beta-D-glucopyranoside], was regioselectively sulfated at the 3 OH position of the terminal galactose using the stannylene procedure. The fucosylation of the sulfated tetrasaccharide was performed using soluble or immobilized fucosyltransferase FucT-III to give the title compound.