Coumarins from the roots of Prangos uloptera

Three new coumarins, 6-O-[β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosyl]-prenyletin, 3″-O-[β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosyl]-oxypeucedanin hydrate and 2″-O-[β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosyl]-oxypeucedanin hydrate, together with six known coumarins, 3″-O-[β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosyl]-heraclenol, 3″-O-(β-d-glucopyranosyl)-heraclenol, tortuoside, 3″-O-(β-d-glucopyranosyl)-oxypeucedanin hydrate, heraclenol and oxypeucedanin hydrate, have been isolated from the roots of Prangos uloptera, and the structures of these coumarins were unequivocally determined by spectroscopic means, notably UV, HRESIMS, and 1D and 2D NMR spectroscopy.     

Dianthus erinaceus var. erinaceus: Extraction,isolation, characterization and antimicrobial activity investigation of novel saponins

A phytochemical analysis of Dianthus erinaceus Boiss. var. erinaceus (Caryophyllaceae) has led to the isolation of two novel triterpenoid saponins, containing an oleane type skeleton, named dianosides K and L (1, 2), along with six known triterpenoid saponins (3–8). On the basis of chemical and spectrometric data, the structures of the new compounds were elucidated as 3-O-[β-d-glucopyranosyl (1 → 3)]–[β-d-glucopyranosyl (1 → 6)]-β-d-glucopyranosyl-olean-12-ene-23α,28-β–dioic acid 28-O-β-d-glucopyranosyl ester (1) and 3-O-[β-d-glucopyranosyl (1 → 3)]–[β-d-glucopyranosyl(1 → 6)]-β-d-glucopyranosyl-olean-12-ene-23α,28-β-dioic acid 28-O-α-l-mannopyranosyl (1 → 6)-β-d-glucopyranosyl ester (2). All isolated natural compounds were structurally characterized by 1D- (¹H, ¹³C, DEPT); 2D- (COSY, HMQC, HMBC) NMR and HR-ESI/MS methods. The antimicrobial activity of compounds 1 and 2 were tested against four Gram-negative, three Gram-positive bacteria and the yeast Candida albicans by the MIC method.     

Echinocystic acid 3,16-O-bisglycosides from Albizia procera

Three triterpene glycosides and two known ones were isolated from the bark of Albizia procera by using chromatographic techniques. The structures of the compounds were determined to be 3-O-β-d-xylopyranosyl-(1 → 2)-β-d-galactopyranosyl-(1 → 6)-2-acetamido-2-deoxy-β-d-glucopyranosyl echinocystic acid 16-O-β-d-glucopyranoside, 3-O-β-d-xylopyranosyl-(1 → 2)-α-l-arabinopyranosyl-(1 → 6)-2-acetamido-2-deoxy-β-d-glucopyranosyl echinocystic acid 16-O-β-d-glucopyranoside and 3-O-α-l-arabinopyranosyl-(1 → 2)-α-l-arabinopyranosyl-(1 → 6)-2-acetamido-2-deoxy-β-d-glucopyranosyl echinocystic acid 16-O-β-d-glucopyranoside. Their structures were determined by NMR techniques including HOHAHA, ¹H-¹H COSY, ROE, HMQC and HMBC experiments together with FABMS as well as acid hydrolysis. To the best of our knowledge, the new compounds are considered the first examples of echinocystic acid 3,16-O-bisglycosides. In contrast to other cytotoxic echinocystic acid glycosides with N-acetyl glucosamine unit, the new glycosides were found inactive when assayed by MTT method for their cytotoxicities against the human tumor cell lines HEPG2, A549, HT29 and MCF7. The results showed the importance of the free hydroxyl group at the aglycone C-16 for exhibiting cytotoxic properties.     

Triterpene glycosides from Agrostemma gracilis

Four triterpene saponins, agrostemmosides A–D were isolated from the methanol extract of Agrostemma gracilis. The structures of the compounds were determined as 3-O-β-d-xylopyranosyloleanolic acid 28-O-β-d-glucopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 6)]-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl ester, 3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-xylopyranosyloleanolic acid 28-O-β-d-glucopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 6)]-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl ester, 3-O-β-d-xylopyranosylechinocystic acid 28-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl ester, 3-O-β-d-xylopyranosylechinocystic acid 28-O-β-d-glucopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 6)]-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl ester by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. To the best of our knowledge this is the first phytochemical report on A. gracilis, and echinocystic acid saponins were encountered for the first time in Caryophyllaceae family.     

Antiplatelet aggregation triterpene saponins from the leaves of Ilex kudingcha

Two new ursane-type triterpene saponins, 3-O-β-d-glucopyranosyl(1 → 3)-[α-l-rhamnopyranosyl(1 → 2)]-α-l-arabinopyranosylurs-12,19(29)-dien-28-oic acid 28-O-α-l-rhamnopyranosyl(1 → 2)-β-d-glucopyranosyl ester (1) and 3-O-β-d-glucopyranosyl(1 → 3)-[α-l-rhamnopyranosyl(1 → 2)]-α-l-arabinopyranosyl-19α,20α-dihydroxyurs-12-en-28-oic acid 28-O-α-l-rhamnopyranosyl(1 → 2)-β-d-glucopyranosyl ester (2), along with thirteen known triterpene saponins were isolated from the n-BuOH part of the MeOH extraction of the leaves of Ilex kudingcha C.J. Tseng (also called “Ku-Ding-Cha”). The structures of new compounds were elucidated on the basis of detailed spectroscopic analysis, including HR-ESI-TOF-MS, 1D and 2D-NMR experiments, and by acid hydrolysis. All the compounds were screened for antiplatelet aggregation activity in vitro, and compounds 1, 2, 3, 7, 12 and 15 showed significant inhibition of platelet aggregation induced by ADP (5 μM) with IC₅₀ values of 14.7 ± 3.7, 11.3 ± 2.5, 17.4 ± 4.6, 20.5 ± 3.1, 8.1 ± 1.5 and 18.9 ± 4.2 μM, respectively.     

A new complex triterpenoid saponin from Calliandra pulcherrima with haemolytic activity and adjuvant effect

A new complex triterpenoid saponin was isolated from the leaves of Calliandra pulcherrima by using chromatographic methods. On the basis of chemical evidence, spectroscopic analyses and comparison of known compounds its structure was established as 3-[(O-α-l-arabinopyranosyl-(1 → 2)-O-α-l-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-β-d-glucopyranosyl)oxy]-(3β)-olean-12-en-28-oic acid O-β-d-xylopyranosyl-(1 → 3)-O-β-d-xylopyranosyl-(1 → 4)-O-[(β-d-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-l-mannopyranosyl-(1 → 2)-6-O-[(2E,6S)-6-[[2-O-[(2E,6S)-6-[[6-deoxy-2-O-[(2E,6S)-2,6-dimethyl-1-oxo-6-(β-d-xylopyranosyloxy)-2,7-octadienyl]-β-d-glucopyranosyl]oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-β-d-xylopyranosyl]oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-β-d-glucopyranosyl ester (1). The haemolytic activity of the saponin was evaluated using in vitro assays, and its adjuvant potential on the cellular immune response against ovalbumin antigen was investigated using in vivo models     

Flavonoids from carnation (Dianthus caryophyllus) and their antifungal activity

A flavonoid glycoside, kaempferol 3-O-β-d-glucopyranosyl (1 → 2)-O-β-d-glucopyranosyl (1 → 2)-O-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (1), along with two known C- and O-flavonoid glycosides (2 and 3, respectively), were isolated from carnation (Dianthus caryophyllus). The structures of the isolated compounds have been elucidated unambiguously by UV, MS, and a series of 1D and 2D NMR analyses. The isolated compounds and other flavonoid glycoside analogues exhibited antifungal activity against different Fusarium oxysporum f.sp. dianthi pathotypes.     

Acylated flavonol pentaglycosides from Baphia nitida leaves

Two new acylated flavonol pentaglycosides were isolated from the butanolic extract of Baphia nitida leaves by Sephadex LH-20 and preparative HPLC. Structural elucidation of kaempferol 3-O-β-d-xylopyranosyl(1 → 3)-(4-O-E-p-coumaroyl-α-l-rhamnopyranosyl(1 → 2))[β-d-glucopyranosyl(1 → 6)]-β-d-galactopyranoside-7-O-α-l-rhamnopyranoside (1) and kaempferol 3-O-β-d-xylopyranosyl(1 → 3)-(4-O-Z-p-coumaroyl-α-l-rhamnopyranosyl(1 → 2))[β-d-glucopyranosyl(1 → 6)]-β-d-galactopyranoside-7-O-α-l-rhamnopyranoside (2) was achieved using UV, NMR, and mass spectrometry, indicating the presence of trans or cis isomers of p-coumaric acid moiety in these novel structures. The antioxidant activity of the two compounds was assessed in the peroxynitrite assay.     

New oleanane saponins from Schefflera kwangsiensis

Four new oleanane-type triterpenoid saponins, schefflesides I–L (1–4), were isolated from the aerial parts of Schefflera kwangsiensis. Their structures were established as oleanolic acid 3-O-β-d-glucopyranosyl (1 → 2) [α-l-arabinopyranosyl (1 → 4)]-β-d-(6-O-methyl) glucuronopyranoside (1), 22α-hydroxyoleanolic acid 3-O-α-l-arabinopyranosyl (1 → 4)-β-d-glucuronopyranoside (2), hederagenin 3-O-α-l-arabinopyranosyl (1 → 4)-β-d-glucuronopyranoside (3) and oleanolic acid 28-O-β-d-glucopyranosyl (1 → 2)-β-d-glucuronopyranosyl ester (4) by spectroscopic analyses (HRESIMS, 1D and 2D NMR) and chemical methods.     

Chemical properties and antiinflammatory activity of a galactomannoglucan from Arecastrum romanzoffianum

A galactomannoglucan (GMG) with an estimated weight-average molar mass of 1.5 × 10⁵ was obtained from an aqueous extract of the mesocarp of fruits of Arecastrum romanzoffianum (Cham.) Becc. by fractionation by Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that GMG has a chain of (1 → 4)-linked β-d-mannopyranosyl residues, a chain of (1 → 3)-linked β-d-galactopyranosyl residues, a chain of (1 → 4)-linked α-d-glucopyranosyl residues, repeating units of β-d-galactopyranosyl-(1 → 4)-β-d-mannopyranosyl and β-d-mannopyranosyl-(1 → 4)-α-d-glucopyranosyl and terminal residues of d-galactopyranosyl and d-glucopyranosyl which comprised galactose, mannose and glucose in the molar ratio of 10:37:53. The polysaccharide exhibited significant antiinflammatory activity against carrageenan-induced mouse paw oedema.     

A new complex triterpenoid saponin from Samanea saman with haemolytic activity and adjuvant effect

A new complex triterpenoid saponin was isolated from the stem bark of Samanea saman by using chromatographic methods. Its structure was established as 3-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]-2,23-dihydroxy-(2β,3β,4α)-olean-12-en-28-oic acid O-β-d-glucopyranosyl-(1 → 3)-O-[O-β-d-glucopyranosyl-(1 → 4)]-O-6-deoxy-α-l-mannopyranosyl-(1 → 2)-6-O-[4-O-[(2E,6S)-2,6-dimethyl-1-oxo-2,7-octadienyl]-6-deoxy-α-l-mannopyranosyl)oxy]-β-d-glucopyranosyl ester (1). Structural elucidation was performed using detailed analyses of ¹H and ¹³C NMR spectra including 2D NMR spectroscopic techniques and chemical conversions. The haemolytic activity of the saponin was evaluated using in vitro assays, and its adjuvant potential on the cellular immune response against ovalbumin antigen was investigated using in vivo models.     

Biotransformation pathways of ginsenoside Rb1 to compound K by β-glucosidases in fungus Paecilomyces Bainier sp. 229

Ginsenoside Rb1 is the most abundant ginsenoside in Panax (ginseng). The hydrolysis of this ginsenoside produces compound K, the biologically active ginsenoside of ginseng. We previously identified a fungus Paecilomyces Bainier sp. 229 (sp. 229), which can efficiently convert ginsenoside Rb1 to compound K. In this report, the ginsenoside hydrolyzing β-glucosidases were isolated from sp. 229 and the pathway of the biotransformation of ginsenoside Rb1 to compound K by sp. 229 was investigated. Based on reverse-phase HPLC and TLC analysis, we found the main metabolic pathway is as follows: ginsenoside Rb1 → ginsenoside Rd → ginsenoside F2 → compound K. Moreover, the results showed that there were other metabolic pathways: ginsenoside Rb1 → ginsenoside XVII → ginsenoside F2 → compound K and ginsenoside Rb1 → ginsenoside Rg3 → ginsenoside Rh2. These processes would allow the specific bioconversion of ginsenoside Rb1 to various ginsenosides using an appropriate combination of specific microbial enzymes.     

Triterpenoid saponins and C-glycosyl flavones from stem bark of Erythrina abyssinica Lam and their cytotoxic effects.

Six new compounds including two oleanane-type triterpenoid saponins (1, 2) and four C-glycosyl flavones (3–6), along with a known saponin (7), three di-C-glycosyl flavones (8–10) and a glycosyl auronol (11), were isolated from the stem bark of Erythrina abyssinica Lam. The structures of the new compounds, identified as 3-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-galactopyranosyl-(1 → 2)-β-d-glucuronopyranosyl]-22-O-β-d-glucopyranosyl sophoradiol (1), 3-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 2)-β-d-glucuronopyranosyl]-22-O-β-d-glucopyranosyl sophoradiol (2), 6-C-β-glucopyranosyl-8-C-β-quinovopyranosyl apigenin (3), 6-C-β-quinovopyranosyl-8-C-β-glucopyranosyl apigenin (4), 8-C-[6″-O-α-l-rhamnopyranosyl-(1‴ → 6″)]-β-glucopyranosyl 7,4′-dihydroxyflavone (5) and 8-C-[6″-O-β-d-xylopyranosyl-(1‴ → 6″)]-β-glucopyranosyl 7,4′-dihydroxyflavone (6), were determined by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, mass spectrometry and acid hydrolysis. These new compounds together with the known saponins 7 were evaluated for their cytotoxic activity against MCF-7 (estrogen dependent) and MDA-MB-231 (estrogen independent) cell lines. The new saponin 2 exhibited the highest cytotoxic activity among tested compounds, exerting a selective inhibitory effect against the proliferation of MCF-7 cells, with lower IC₅₀ value (12.90 μM) than that of the positive control, resveratrol (13.91 μM). Structure–activity relationship of these compounds is also discussed.     

Chemical properties and adjuvant activity of a galactoglucomannan from Acrocomia aculeata

A galactoglucomannan (GGM) with an estimated weight-average molar mass of 3.5 × 10⁵ was obtained from an aqueous extract of the mesocarp of fruits of Acrocomia aculeata (Jacq.) Lodd. by fractionation by Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that GGM has a main chain of (1 → 4)-linked β-d-mannopyranosyl residues attached to an initial chain of (1 → 3)-linked β-d-galactopyranosyl residues and a terminal chain of (1 → 4)-linked α-d-glucopyranosyl residues which comprised galactose, glucose and mannose in the molar ratio of 18:22:60. The adjuvant potential of the polysaccharide on the cellular immune response against ovalbumin antigen was investigated using in vivo assays.     

Chemical properties and immunostimulatory activity of a water-soluble polysaccharide from the clam of Hyriopsis cumingii Lea

A water-soluble polysaccharide HCLPS-1 was isolated from clam of Hyriopsis cumingii Lea by hot water, DEAE-cellulose and Sephadex-G200, gel-permeation chromatography and tested for its immunostimulatory activities. Its structural characteristics were investigated by UV, IR, HPLC, NMR spectroscopy, methylation analysis and GLC–MS. HCLPS-1 consisted of glucose and xylose with the molar ratio of 35:1. Based on the data obtained, HCLPS-1 was determined to has a main chain of (1 → 4)-linked β-d-glucopyranosyl residues, with a weight-average molecular weight of about 1.56 × 10⁵ Da. HCLPS-1 not only could significantly promote concanavalin A (Con A), lipopolysaccharide (LPS)-stimulated splenocytes proliferation in concentration-dependent manner in vitro, but also increase Con A- and LPS-induced splenocytes proliferation in mice immunized with the sheep red blood cell (SRBC). Meanwhile, HCLPS-1 remarkably promoted 2, 4-dinitrofluorobenzene (DNFB)-induced delayed-type hypersensitivity (DTH) reactions. These results suggested that HCLPS-1 could improve both specific and non-specific cellular immune response and might be explored as a potential natural immunomodulator.     

Structural characterization and anti-fatigue activity of polysaccharides from the roots of Morinda officinalis

Three polysaccharides MP-1, MP-2, and MP-3 were isolated from hot water extract of Chinese medicine Morinda officinalis through 95% ethanol precipitation and gel-filtration chromatography (DEAE-Sepharose CL-6B column and Sephadex G-75 or G-100 column). MP-1 was identified as an inulin-type fructan with simple linear (2 → 1)-linked structure. Both MP-2 and MP-3 were acidic polysaccharides which consisted predominantly of galacturonic acid, arabinose and galactose. Partial structure characterization of MP-3 was carried out by partial acid hydrolysis and periodate oxidation. The total polysaccharides of the herb were tested in mice weight-loaded swimming model and were found to have anti-fatigue activity.     

New cytotoxic steroidal saponins from Cestrum parqui

Two new steroidal saponins, 25(R)-3β [(O-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranosyl)oxy]-5α, 15β, 22R, 25R-spirostan-3,15-diol (1, named parquispiroside) and 25R-26-[(β-d-glucopyranosyl)Oxy]-(3β [(O-β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranosyl)oxy], 5α, 15β, 22R, 25R)-furostane-3,15,22-triol (2, named parquifuroside), along with the known saponins, capsicoside D (3) and 22-OMe-capsicoside D (4) and the known glycoside, benzyl primeveroside (5), were isolated from the leaves of Cestrum parqui. The structures of these compounds were elucidated by careful analysis of 1D and 2D NMR spectra and ESIMS data. Parquispiroside (1) exhibited moderate inhibition of Hela, HepG2, U87, and MCF7 cell lines with IC₅₀ values in the range of 3.3–14.1 μM.     

Bafouoside C,a new triterpenoid saponin from the roots of Cussonia bancoensis Aubrev. & Pellegr.

A new triterpenoid saponin named bafouoside C 3-O-β-d-glucopyranosyl-(1 → 4)-[β-d-galactopyranosyl-(1 → 2)]-β-d-glucuronopyranosyloleanolic acid 28-O-β-d-glucopyranosyl ester; (1), together with five known compounds 3-O-β-d-galactopyranosyl-(1 → 2)-β-d-glucuronopyranosyloleanolic acid (2), 23-hydroxyursolic acid (3), 28-O-α-l-rhamnopyranosyl-(1 → 4)-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranosyl-23-hydroxyursolic acid (4), 3-O-β-d-glucopyranosyl-23-hydroxyursolic acid (5), and 3-O-α-l-arabinopyranosyl-23-hydroxyursolic acid (6), were isolated from the roots of Cussonia bancoensis Aubrev. & Pellegr. Their structures were established on the basis of 1D- and 2D NMR data, mass spectrometry and chemical methods. The NMR data of the known compounds, as far as we know, are herein reported for the first time in CD₃OD. Compound 3 exhibited a weak cytotoxic activity against MDA-MB 231 human breast adenocarcinoma, A375 human malignant melanoma, and HCT116 human colon carcinoma cell lines.     

Cycloartane glycosides from Astragalus gombo

Six new cycloartane-type triterpene glycosides named 3-O-[β-d-glucopyranosyl(1 → 2)-β-d-xylopyranosyl]-3β,16β,23(R),24(R),25-pentahydroxycycloartane (1), 3-O-[β-d-glucopyranosyl(1 → 2)-β-d-xylopyranosyl]-3β,16β,23(R),24(R)-tetrahydroxy-25-dehydrocycloartane (2), 3-O-[β-d-xylopyranosyl]-6α-acetoxy-23α-methoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (3), 3-O-[β-d-xylopyranosyl]-6α-acetoxy-23α-butoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (4), 3-O-[β-d-glucopyranosyl(1 → 2)]-β-d-xylopyranosyl]-6α-acetoxy-23α-methoxy-16β,23(R)-epoxy-24,25,26,27-tetranorcycloartane (5), 3-O-[β-d-glucopyranosyl(1 → 2)]-β-d-xylopyranosyl]-23α-methoxy-16β,23(R)-epoxy-4,25,26,27-tetranorcycloartane (6), in addition to three known secondary metabolites consisting of another cycloartane triterpene glycoside and two flavonol glycosides, were isolated from the aerial parts of Astragalus gombo Coss. & Dur. (Fabaceae). The structures of the isolated compounds were established by spectroscopic methods, including 1D and 2D-NMR, mass spectrometry and comparison with literature data.     

Structural elucidation and immunological activity of a polysaccharide from the fruiting body of Armillaria mellea

The water-soluble polysaccharide (AMP), with a molecular mass of 7.8 × 10³ Da as determined by high-performance size-exclusion chromatography (HPSEC), was obtained from the fruiting body of Armillaria mellea. Methylation, Smith degradation, acetolysis, ¹H and ¹³C NMR spectroscopy and acid hydrolysis studies were conducted to elucidate its structure. The results indicated that AMP consisted of a backbone composed of (1→6)-linked-α-d-glucopyranosyl, (1→2,6)-linked-α-d-glucopyranosyl and (1→6)-linked-α-d-galactopyranosyl residues in the ratio of 3:1:1, and terminated with one single terminal (1→)-β-d-glucopyranosyl at the O-2 position of (1→2,6)-linked-α-d-glucopyranosyl, on average, along the main chain. Preliminary tests in vitro showed that AMP has stimulating effects on murine lymphocyte proliferation induced by concanavalin A or lipopolysaccharide in a dose-dependent manner. It is a possible potential immunopotentiating agent for use in health-care food or medicine.