Saponins from Astragalus hareftae (NAB.) SIRJ.

Four cycloartane- (hareftosides A–D) and oleanane-type triterpenoids (hareftoside E) were isolated from Astragalus hareftae along with fifteen known compounds. Structures of the compounds were established as 3,6-di-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (1), 3,6,24-tri-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (2), 3-O-β-d-xylopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),25(S)-epoxycycloartane (3), 16-O-β-d-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane (4), 3-O-[β-d-xylopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucuronopyranosyl]-soyasapogenol B (5) by the extensive use of 1D- and 2D-NMR experiments along with ESI-MS and HR-MS analyses.     

Synthesis of quercetin glycosides and their melanogenesis stimulatory activity in B16 melanoma cells

4′-O-β-d-Glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyra-noside (3) was isolated from Helminthostachys zeylanica root extract as a melanogenesis acceleration compound and was synthesized using rutin as the starting material. Related compounds were also synthesized to understand the structure–activity relationships in melanin biosynthesis.Melanogenesis activities of the glycosides were determined by measuring intracellular melanin content in B16 melanoma cells. Among the synthesized quercetin glycosides, quercetin-3-O-β-d-glucopyranoside (1), quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (2), and 3 showed more potent intracellular melanogenesis acceleration activities than theophyline used as positive control in a dose-dependent manner with no cytotoxic effect.     

Nebulosides A–B,novel triterpene saponins from under-ground parts of Gypsophila arrostii Guss. var. nebulosa

A bioassay-guided phytochemical analysis of the triterpene saponins from under ground parts of Gypsophila arrostii var. nebulosa allowed the isolation of two triterpene saponins; nebuloside A, B based on gypsogenin and quillaic acid aglycone. Two new oleanane type triterpenoid saponins (nebuloside A, B) and three known saponins (1–3) were isolated from the root bark of Gypsophila arrostii var. nebulosa. The structures of the two new compounds were elucidated as 3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosyl quillaic acid 28-O-β-d-glucopyranosyl-(1→3)-[β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)]-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranosyl ester (nebuloside A) and 3-O-β-d-xylopyranosyl-(1→3)-[β-d-galactopyranosyl(1→3)-β-d-galactopyranosyl-(1→2)]-β-d-glucuronopyranosyl gypsogenin 28-O-β-d-glucopyranosyl-(1→3)-[β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)]-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranosyl ester (nebuloside B), on the basis of extensive spectral analysis and chemical evidence. Nebuloside A and B showed toxicity enhancing properties on saporin a type-I RIP without causing toxicity by themselves at 15 μg/mL.     

Phenolic glycosides from Cucumis melo var. inodorus seeds

A new phenolic glycoside (E)-4-hydroxycinnamyl alcohol 4-O-(2′-O-β-d-apiofuranosyl)(1″ → 2′)-β-d-glucopyranoside (1) was isolated and identified from Cucumis melo seeds together with benzyl O-β-d-glucopyranoside (2), 3,29-O-dibenzoylmultiflor-8-en-3α,7β,29-triol (3) and 3-O-p-amino-benzoyl-29-O-benzoylmultiflor-8-en-3α,7β,29-triol (4). Their structures were elucidated by extensive NMR experiments including ¹H–¹H (COSY, TOCSY, ROESY) and ¹H–¹³C (HSQC and HMBC) spectroscopy and chemical evidence. The multiflorane triterpene esters were identified as new melon constituents.     

Steroidal saponins from the leaves of Cordyline fruticosa (L.) A. Chev. and their cytotoxic and antimicrobial activity

Three new steroidal saponins, spirosta-5,25(27)-diene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranoside (fruticoside H) 1, 5α-spirost-25(27)-ene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-(4-O-sulfo)-β-d-fucopyranoside (fruticoside I) 2, and (22S)-cholest-5-ene-1β,3β,16β,22-tetrol 1-O-β-galactopyranosyl-16-O-α-l-rhamnopyranoside (fruticoside J) 3, together with the known quercetin 3-O-β-d-glucopyranoside, quercetin 3-O-[6-trans-p-coumaroyl]-β-d-glucopyranoside, quercetin 3-rutinoside, apigenin 8-C-β-d-glucopyranoside and farrerol, were isolated from the leaves of Cordyline fruticosa. Their structures were elucidated by spectroscopic techniques (¹H NMR, ¹³C NMR, HSQC, ¹H–¹H COSY, HMBC, TOCSY, NOESY), mass spectrometry (HRESIMS, Tandem MS–MS), chemical methods and by comparison with published data. Compounds 1 and 2 showed moderate cytotoxic activity against MDA-MB 231 human breast adenocarcinoma cell line, HCT 116 human colon carcinoma cell line, and A375 human malignant melanoma cell line, while compound 3 was not active. Compound 2 also showed a moderate antibacterial activity against the Gram-positive Enterococcus faecalis.     

Chevalierinoside B and C: Two new isoflavonoid glycosides from the stem bark of Antidesma laciniatum Muell. Arg (syn. Antidesma chevalieri Beille)

Chevalierinosides B (1) and C (2), two new isoflavonoid glycosides, characterized as biochanin A 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside] and genistein 7-O-[β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside], together with the known isoflavonoids, chevalierinoside A (3) and genistein 7-O-β-d-glucopyranoside (4), kaempferol 3-O-β-d-glucopyranoside (5) and triterpenes, friedelin (6), betulinic acid (7), 30-oxobetulinic acid (8), 30-hydroxybetulinic acid (9), were isolated from the stem bark of Antidesma laciniatum Muell. Arg. (syn. Antidesma chevalieri Beille). Their structures were established by direct interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (¹H, ¹³C and DEPT) and 2D-NMR (COSY, NOESY, TOCSY, HSQC and HMBC), and by comparison with the literature.     

Phenylethanoid glycosides from the leaves of Magnolia hodgsonii

Three new phenylethanoid glycosides, 2-(3-hydroxy-4-methoxyphenyl)ethyl 1-O-β-d-allopyranoside (hodgsonialloside A, 1), 2-(3-hydroxy-4-methoxyphenyl)ethyl 1-O-β-d-glucopyranosyl-(1 → 4)-β-d-allopyranoside (hodgsonialloside B, 2) and 2-(3-methoxy-4-hydroxyphenyl)ethyl 1-O-β-d-allopyranoside (hodgsonialloside C, 3) were isolated from the leaves of Magnolia hodgsonii in addition to six known compounds, tyrosol 4-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside (4), kaempferol 3-O-neohesperidoside (5), kaempferol 3-O-rutinoside (6), kaempferol 3-O-α-l-rhamnopyranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (7), (+)-syringaresinol O-β-d-glucopyranoside (8), and oblongionoside C (9). The structure elucidation of these compounds was based on analyses of physical and spectroscopic data including 1D and 2D NMR experiments.     

New cytotoxic dihydrochalcone and steroidal saponins from the aerial parts of Sansevieria cylindrica Bojer ex Hook

A new dihydrochalcone, 2‘,4‘-dihydroxy-3‘-methoxy-3,4-methylenedioxy-8-hydroxymethylene dihydrochalcone 1 and two new steroidal saponins, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside 2, (25S)-ruscogenin-3-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranoside 3, together with three known steroidal saponins (25S)-ruscogenin-3-O-β-d-glucopyranoside 4, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 5 and (25R)-26-O-β-d-glucopyranosyl-furost-5-ene-1β,3β,22α,26-tetrol-1-O-α-L-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 6 were isolated from the aerial parts of Sansevieria cylindrica. The structures of the new compounds were established by UV, IR, EI-MS, HR-ESI–MS as well as 1D (¹H,¹³C and DEPT-135) and 2D (HSQC, HMBC and TOCSY) NMR spectral analysis. The isolated compounds 1-6 were assayed for in vitro cytotoxicities against the three human tumor cell lines HT116, MCF7 and HepG2. Compound 1 showed a moderate cytotoxicity against MCF7. Compounds 2, 3 and 6 exhibited moderate cytotoxicities against the three used cell lines and compound 5 showed marked cytotoxicities against all used cell lines.     

Microbial metabolism of prenylated apigenin derivatives by Mucor hiemalis

6-Prenylapigenin (1) and 8-prenylapegenin (2) were semi-synthesized from apigenin by nuclear prenylation. Morusin (3) was isolated from the root bark of Morus alba L. The microbial transformation studies of these three bioactive prenylated apigenin derivatives were performed using eighteen cell cultures in order to select microorganisms capable of transforming them. It was identified that Mucor hiemalis (KCTC 26779) showed the ability to metabolize the parent compounds (1–3) into three new (4–6) and one known (7) glucosylated derivatives with high efficiency. Their structures were established as 6-prenylapigenin 7-O-β-d-glucopyranoside (4), 8-prenylapigenin 7-O-β-d-glucopyranoside (5), morusin 5-O-β-d-glucopyranoside (6), and morusin 4′-O-β-d-glucopyranoside (7) by the spectroscopic methods.     

Thiophenes,polyacetylenes and terpenes from the aerial parts of Eclipata prostrata

One new bithiophenes, 5-(but-3-yne-1,2-diol)-5′-hydroxy-methyl-2,2′-bithiophene (2), two new polyacetylenic glucosides, 3-O-β-d-glucopyranosyloxy-1-hydroxy-4E,6E-tetradecene-8,10,12-triyne (8), (5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-β-d-glucopyranoside (9), six new terpenoid glycosides, rel-(1S,2S,3S,4R,6R)-1,6-epoxy-menthane-2,3-diol-3-O-β-d-glucopyranoside (10), rel-(1S,2S,3S,4R,6R)-3-O-(6-O-caffeoyl-β-d-glucopyranosyl)-1,6-epoxy menthane-2,3-diol (11), (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-d-glucopyranoside (12), 3β,16β,29-trihydroxy oleanane-12-ene-3-O-β-d-glucopyranoside (13), 3,28-di-O-β-d-glucopyranosyl-3β,16β-dihydroxy oleanane-12-ene-28-oleanlic acid (14), 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl oleanlic-18-ene acid-28-O-β-d-glucopyranoside (15), along with fifteen known compounds (1, 3–7, and 16–24), were isolated from the aerial parts of Eclipta prostrata. Their structures were established by analysis of the spectroscopic data. The isolated compounds 1–9 were tested for activities against dipeptidyl peptidase IV (DPP-IV), compound 7 showed significant antihyperglycemic activities by inhibitory effects on DPP-IV in human plasma in vitro, with IC₅₀ value of 0.51 μM. Compounds 10–24 were tested in vitro against NF-κB-luc 293 cell line induced by LPS. Compounds 12, 15, 16, 19, 21, and 23 exhibited moderate anti-inflammatory activities.     

Methylated anthocyanidin glycosides from flowers of Canna indica

Methylated anthocyanin glycosides were isolated from red Canna indica flower and identified as malvidin 3-O-(6-O-acetyl-β-d-glucopyranoside)-5-O-β-d-glucopyranoside (1), malvidin 3,5-O-β-d-diglucopyranoside (2), cyanidin-3-O-(6″-O-α-rhamnopyranosyl-β-glucopyranoside (3), cyanidin-3-O-(6″-O-α-rhamnopyranosyl)-β-galactopyranoside (4), cyanidin-3-O-β-glucopyranoside (5) and cyanidin-O-β-galactopyranoside (6) by HPLC-PDA. Their structures were subsequently determined on the basis of spectroscopic analyses, that is, ¹H NMR, ¹³C NMR, HMQC, HMBC, ESI-MS, and UV-vis. Compounds (1-4) were found to be in major quantity while compounds (5-6) were in minor quantity.     

Flavonoid glycosides from the aerial parts of Curcuma comosa

Four new flavonoid glycosides, curcucomosides A–D (1–4), three known flavonoid glycosides, 5–7, and four known diarylheptanoids, 8–11, were isolated from the ethanol extract of the aerial parts of Curcuma comosa. The structures of the new compounds were established as rhamnazin 3-O-α-l-arabinopyranoside (1), rhamnocitrin 3-O-α-l-arabinopyranoside (2), rhamnazin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (3), and rhamnocitrin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (4) by spectroscopic analysis and chemical reactions whereas those of the known compounds were identified by spectral comparison with those of the reported values.     

Two new spirostanol saponins from the the roots and rhizomes of Tupistra chinensis

Two new spirostanol saponins (1) and (2), together with three known saponins (3–5), were isolated from the roots and rhizomes of Tupistra chinensis, and their structures were determined as (20S, 22R)-spirost-25(27)-en-1β, 3β, 4β, 5β-tetraol-5-O-β-d-glucopyranoside (1) and (20S, 22R)-spirost-25(27)-en-1β, 3β, 5β-triol-5-O-β-d-glucopyranoside (2), (20S, 22R)-spirost-25(27)-en-1β, 2β, 3β, 4β, 5β-pentaol-5-O-β-d-glucopyranoside (3), Δ²⁵⁽²⁷⁾-pentrogenin (4) and ranmogenin A (5) on the basis of physicochemical properties and spectral analysis. The isolated compounds were evaluated for their cytotoxic activities against A549 and H1299 tumor cell lines in vitro. Among them, compound 2 showed cytotoxicities against A549 cells (IC₅₀ 52.66 ± 3.12 μmol L⁻¹) and H1299 cells (IC₅₀ 57.29 ± 2.51 μmol L⁻¹), respectively.     

Flavonol glycosides and lignans from the leaves of Opilia amentacea

Two previously undescribed flavonol tetraglycosides, isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (1) and isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside (2), along with nine known compounds including seven flavonoids and two lignans, were isolated from the leaves of Opilia amentacea Roxb (Opiliaceae). Their structures were established on the basis of spectroscopic analysis. The DPPH radical scavenging activity of compounds 1–11 was evaluated. In addition, all compounds were evaluated for their tyrosinase inhibitions by using in vitro mushroom tyrosinase assay. Only 5,5-dimethoxylariciresinol-4-O-β-d-glucopyranoside (10) and eleutheroside E1 (11) exhibited significant tyrosinase inhibition (IC₅₀ 42.1 and 28 μM, respectively) and DPPH radical scavenging activity (IC₅₀ 85.1 and 42.1 μM, respectively) compared with the positive controls.     

Four new steroidal glycosides from Solanum torvum and their cytotoxic activities

Two novel C-22 steroidal lactone saponins, namely solanolactosides A, B (1, 2) and two new spirostanol glycosides, namely torvosides M, N (3, 4) were isolated from ethanol extract of aerial parts of Solanum torvum. Their structures were characterized as solanolide 6-O-[α-l-rhamnopyranosyl-(1 → 3)-O-β-d-quinovopyranoside] (1), solanolide 6-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-quinovopyranoside] (2), yamogenin 3-O-[β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside] (3) and neochlorogenin 3-O-[β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside] (4) on the basis of spectroscopic analysis. The cytotoxicities of the saponins (1-4) were evaluated in vitro against a panel of human cancer cell lines. Compounds 3 and 4 showed significant cytotoxic activity with the cell lines.     

A furan-2-carbonyl C-glucoside and an alkyl glucoside from the parasitic plant,Dendrophthoe pentandra

A new furan-2-carbonyl C-(6′-O-galloyl)-β-glucopyranoside (scleropentaside F, 1) and a new alkyl glucoside [butane-2,3-diol 2-(6′-O-galloyl)-O-β-glucopyranoside, 2] were isolated from the entire hemi-parasitic plant, Dendrophthoe pentandra growing on Tectona grandis together with ten known compounds including, benzyl-O-β-d-glucopyranoside (3), benzyl-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside (4), benzyl-O-β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranoside (5), methyl gallate 3-O-β-d-glucopyranoside (6), methyl gallate 3-O-(6′-O-galloyl)-β-d-glucopyranoside (7), (+)-catechin (8), procyanidin B-1 (9) and procyanidin B-3 (10), bridelionoside A (11), and kiwiionoside (12). In addition, compounds 1, 3–9 were isolated from this species growing on the different host, Mangifera indica. The structure elucidations were based on physical data and spectroscopic evidence including 1D and 2D experiments.     

A new semiterpenoid glycoside and a new benzofuran derivative glycoside from the roots of Heracleum dissectum

A new semiterpenoid glycoside, 3-methylbutan-1, 3-diol-1-O-β-d-glucopyranoside (1) and a new benzofuran derivative glycoside, 6-carboxylethyl-benzofuran-5-O-β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranoside (2), together with seven known compounds (3-9) were isolated from the roots of Heracleum dissectum Ledeb. Their structures were elucidated on the basis of physicochemical properties and the detailed interpretation of various spectroscopic data. All the isolated compounds were screened for anti-inflammatory activity in vitro. And the result showed that compound 2 exhibited significantly inhibitory activity on nitric oxide production in RAW264.7 cells, which IC₅₀ value was equivalent to that of the positive control indomethacin.     

New steroidal saponins of Agave americana

Two new saponins, agavasaponin E and agavasaponin H have been isolated from the methanolic extract of Agave americana leaves and their structures elucidated. Agavasaponin E is 3-O-[β-d-xylopyranosyl-(1→2glc1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-α-d-galactopyranosyl]-(25R)-5α-spirostan-12-on-3β-ol, whereas agavasaponin H is 3-O-[β-d-xylopyranosyl-(1→2 glc 1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3 glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-β-d-galactopyranosyl]-26-O-[β-d-glucopyranosyl]-(25R)-5α-furostan-12-on-3β,22α,26-triol.     

Chemical constituents from the fruit of Gardenia jasminoides and their inhibitory effects on nitric oxide production

Three new iridoid glycosides, 6″-O-trans-caffeoylgenipin gentiobioside (1), genipin 1-O-β-d-apiofuranosyl (1→6)-β-d-glucopyranoside (2), genipin 1-O-α-d-xylopyranosyl (1→6)-β-d-glucopyranoside (3), three new monocyclic monoterpenoids, jasminoside R (4), jasminoside S (5), jasminoside T (6), together with nine known iridoid glycosides (7–15) and three crocetin glycosides (16–18), were isolated from the fruit of Gardenia jasminoides. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Inhibitory effects of the isolated compounds on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated. Compounds 8 and 18 showed strong inhibitory activity on NO production with IC₅₀ values of 11.14 ± 0.67 and 5.99 ± 0.54 μM, respectively.     

Unusual oleanane-type saponins from Arenaria montana

Three oleanane-type saponins, 3-O-β-d-glucopyranosylechinocystic acid 28-O-β-d-xylopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-α-l-rhamnopyranosyl ester (1), 3-O-β-d-glucopyranosylechinocystic acid 28-O-α-l-arabinopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→2)]-α-l-rhamnopyranosyl ester (2), 3-O-β-d-glucopyranosylcaulophyllogenin 28-O-β-d-apiofuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[β-d-apiofuranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-α-l-rhamnopyranosyl ester (3) were isolated from the whole plant of Arenaria montana. Their unusual structures for the Caryophyllaceae family were established mainly by 2D NMR techniques and mass spectrometry.