Coumarins and triterpenoid glycosides from the roots ofPatrinia scabiosaefolia

From the roots ofPatrinia scabiosaefolia (Valerianaceae), scopoletin (1), esculetin (2), oleanonic acid (3), 3-O-α-l-rhamnopyranosyl(1→2)-α-l-arabinopyranosyl oleanolic acid (4) and 3-O-α-l-rhamnopyranosyl (1→2)-α-l-arabinopyranosyl hederagenin (5) were isolated and characterized by spectral data.     

Flavonol glycosides from the aerial parts of<Emphasis Type="Italic">Aceriphyllum rossii</Emphasis> and their antioxidant activities

The methanol extract obtained from the aerial parts ofAceriphyllum rossii (Saxifragaceae) was fractionated into ethyl acetate (EtOAc),n-BuOH and H₂O layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc andn-BuOH layers afforded six flavonol glycosides. They were identified as kaempferol 3-O-β-D-glucopyranoside (astragalin,1), quercetin 3-O-β-D-glucopyranoside (isoquercitrin,2), kaempferol 3-O-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside (3), quercetin 3-O-α-L-rhamnopyranosyl (1→6)-β-D-glucopyrano-side (rutin,4), kaempferol 3-O-[α-L-rhamnopyranosyl (1→4)-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside] (5) and quercetin 3-O-[α-L-rhamnopyranosyl (1→4)-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside] (6) on the basis of several spectral data. The antioxidant activity of the six compounds was investigated using two free radicals such as the ABTS free radical and superoxide anion radical. Compound1 exhibited the highest antioxidant activity in the ABTS2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging method. 100 mg/L of compound1 was equivalent to 72.1±1.4 mg/L of vitamin C, and those of compounds3 and5 were equivalent to 62.7±0.5 mg/L and 54.3±1.3 mg/L of vitamin C, respectively. And in the superoxide anion radical scavenging method, compound5 exhibited the highest activity with an IC₅₀ value of 17.6 ± 0.3 μM. In addition, some physical and spectral data of the flavonoids were confirmed.     

Cytotoxic activities of diarylheptanoids from Alnus japonica

The diarylheptanoids (1–10) 1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-O-β-D-glucopyranosyl(1→3)-β-D-xylopyranoside (1), 1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-O-β-D-apiofuranosyl(1→6)-β-D-glucopyranoside (2), 1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-β-D-glucopyranoside (3), 1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane (4), 1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-β-D-glucopyranoside (5), oregonin (6), hirsutanonol (7), hirsutenone (8), 1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-O-β-D-xylopyranoside (9), and platyphylloside (10), isolated from the bark of Alnus japonica, were analyzed for their cytotoxic activities on various human and mouse cancer cell lines. The cytotoxic activities of these ten compounds were evaluated against murine B16 melanoma, human SNU-1 gastric cancer, human SNU-354 hepatoma cancer and human SNU-C4 colorectal cell lines. The diarylheptanoids showed potent cytotoxic activities against murine B16 melanoma cells and human SNU-C1 gastric cancer cell when the cell viability was analyzed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) assay.     

Aromatic compounds and triterpenoidal saponins fromClematis koreana var.umbrosa

From the methanolic extract of aerial parts ofClematis koreana var.umbrosa, one new triterpenoidal saponin, 3-O-β-D-xylopyranosyl(1–3)-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl(1–4)-β-D-glucopyranosyl(1–6)-β-D-glucopyranosyl ester, along with five known aromatic compounds and two known triterpenoidal saponins were isolated.     

Five new glycosides from <Emphasis Type="Italic">Hypericum erectum</Emphasis> Thunb.

Five new glycosides, quercetin 3′-O-β-d-galactopyranoside (1), quercetin 3-O-(2″-acetyl)-β-d-glucopyranoside (2), 4,6-dihydroxy-2-methoxyphenyl 1-O-β-d-glucopyranoside (3), 4-hydroxy-2,6-dimethoxyphenyl 1-O-α-l-rhamnopyranosyl (1 → 6)-β-d-glucopyranoside (4) and 3-methyl-but-2-en-1-yl β-d-glucopyranosyl (1 → 6)-β-d-glucopyranoside (5), were isolated from Hypericum erectum Thunb. Their structures were established on the basis of spectral and chemical data.     

A dimeric triterpenoid glycoside and flavonoid glycosides with free radical-scavenging activity isolated from <Emphasis Type="Italic">Rubus rigidus</Emphasis> var. <Emphasis Type="Italic">camerunensis</Emphasis>

The aerial part of Rubus rigidus var. camerunensis (Rosaceae) is used to treat respiratory and cardiovascular disorders in the Cameroonian traditional medicine. The ethanol extract exhibited more potent antioxidant activity (E_maxs of 119% and 229% activity on DPPH and β-carotene test) than aqueous extract. Bioactivity-guided fractionation of the ethanol extract based on free radical-scavenging assay (DPPH assay) afforded five flavonoid glycosides (four flavonol glycosides and an anthocyanin) and three glucosides of 19α-hydroxyursane-type triterpenoid (two monomeric and one dimeric triterpenoids). The flavonoids were identified as kaempferol 3-O-(2″-O-E-p-coumaroyl)-β-D-glucopyranoside (1), kaempferol-3-O-β-D-glucopyranoside (astragalin, 2), kaempferol-3-O-α-L-arabinofuranoside (juglanin, 3), quercetin-3-O-β-D-glucopyranoside (isoquercitrin, 4), pelargonidin-3-O-β-D-glucopyranoside (callistephin, 5). The three triterpenoids were 2α, 3β, 19α, 23-tetrahydroxyurs-12-ene-28-O-β-D-glucopyranosyl ester (nigaichigoside F₁, 6), 2α, 3β, 19α-trihydroxyurs-12-ene-23-carboxyl-28-O-β-D-glucopyranosyl ester (suavissimoside R₁, 7) as monomeric triterpenoids and coreanoside F₁ (8) as a dimeric triterpenoid. The flavonoids exhibited potent antioxidant activities (66 to 93.56% against DPPH radical) and they were also active on β-carotene test. Coreanoside F₁ exhibited a 63% antioxidant activity, meanwhile the other two triterpenoids showed a weak activity. Three important facts on structure-activity relationship were observed: Compound 8, a dimeric triterpenoid glycoside, strongly enhanced antioxidant activity of its monomers, compound 3 with 3-O-α-L-arabinofuranyl has much more potent activity than compound 2 with 3-O-β-D-glucopyranosyl, and antocyanin (5) is more potent than its corresponding flavonol glycosides.     

(<Emphasis Type="Italic">Z</Emphasis>)-3-Hexenyl diglycosides from <Emphasis Type="Italic">Spermacoce laevis</Emphasis> Roxb.

A new (Z)-3-hexenyl O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside was isolated from the aerial part of Spermacoce laevis, along with 17 known compounds: (6S,9R)-roseoside, (Z)-3-hexenyl O-β-d-glucopyranoside, (Z)-3-hexenyl O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside, (Z)-3-hexenyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, phenyethyl O-β-d-glucopyranoside, phenyethyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, phenyethyl O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside, benzyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, benzyl O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside, asperuloside, 6α-hydroxyadoxoside, asperulosidic acid, kaempferol 3-O-β-d-glucopyranoside, kaempferol 3-O-rutinoside, quercetin 3-O-β-d-galactopyranoside, quercetin 3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside, and rutin. The structure determinations were based on physical data and spectroscopic evidence.     

Antioxidant flavone glycosides from the leaves of<Emphasis Type="Italic">Sasa borealis</Emphasis>

Sasa borealis (Poaceae) is a perennial medicinal plant which is a major source of bamboo leaves in Korea. Then-BuOH extract ofS. borealis leaves exhibited significant antioxidant activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and a cytoprotective effect against oxidative damage in HepG2 cells. Bioactivity-guided fractionation by column chromatography led to the isolation of two antioxidative flavonoid C-glycoside derivatives, isoorientin (2) and isoorientin 2”-O-α-i_-rhamnoside (4) along with tricin 7-0-β-D-glucopyranoside (1) and apigenin 6-C-β-D-xylopyranosyl-8-C-β-D-glucopyranoside (3). Their structures were identified on the basis of chemical and spectroscopic methods. The radical scavenging activity and cytoprotective effect against oxidative damage of all the isolated compounds were also evaluated. Isoorientin (2) and isoorientin 2-O-α-L-rhamnoside (4) showed potent free radical scavenging activity with 1C₅₀ values of 9.5 and 34.5 μM, respectively, and strong cytoprotective effects againstt-BOOH-induced oxidative damage in HepG2 cells, at very low concentrations of 1.1 μM isoorientin and 0.8 μM isoorientin 2-O-α-L-rhamnoside. This is the first report of the isolation and antioxidant activity of compounds 2 and 4 from S.borealis.     

Tissue factor inhibitory sesquiterpene glycoside from<Emphasis Type="Italic">Eriobotrya japonica</Emphasis>

Tissue factor (TF, tissue thromboplastin) is a membrane bound glycoprotein, which accelerates the blood clotting, activating both the intrinsic and the extrinsic pathways to serve as a cofactor for activated factor VII (Vlla). The TF-factor Vlla complex (TF/Vlla) proteolytically activates factors IX and X, which leads to the generation of thrombin and fibrin clots. In order to isolate TF inhibitors, by means of a bioassay-directed chromatographic separation technique, from the leaves ofEriobotrya japonica Lindley (Rosaceae), a known sesquiterpene glycoside (2) and ferulic acid (3) were isolated as inhibitors that were evaluated using a single-clotting assay method for determining TF activity. Another sesquiterpene glycoside (1) was also isolated but was inactive in the assay system. Compound3 was yielded by alkaline hydrolysis of compound2. The structures of compounds1, 2, and3 were identified by means of spectral analysis as 3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranosyl nerolidol (1), 3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyr-anosyl-(1→2)-[α-L-(4-trans-feruloyl)-rhamnopyranosyl-(1→6)]-β-D-glucopyranosyl nerolidol (2) and ferulic acid (3), respectively. Compounds2 and3 inhibited 50% of the TF activity at concentrations of 2 and 369 μM/TF units, respectively.     

New triterpene saponins from <Emphasis Type="Italic">Stenocereus eruca</Emphasis> (Cactaceae)

Two new triterpene saponins, named stellatoside B (1) and erucasaponin A (2), were isolated from a cactaceous plant, Stenocereus eruca A. C. Gibson & K. E. Horak (Machaerocereus eruca Br. & R.). The structures of 1 and 2 were elucidated as 3-O-β-d-xylopyranosyl-(1→2)-β-d-glucopyranosyl-(1→2)-β-d-glucuronopyranosyl stellatogenin and 3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→3)]-β-d-glucuronopyranosyl betulinic acid 28-O-α-l-rhamnopyranosyl ester, respectively, on the basis of their spectroscopic data.     

Chromone and flavonol glycosides from <Emphasis Type="Italic">Delphinium hybridum</Emphasis> cv. “Belladonna Casablanca”

One new chromone and six known flavonol glycosides were isolated from the stems and leaves of Delphinium hybridum cv. “Belladonna Casablanca” (Ranunculaceae). The new chromone glycoside was elucidated as 2-methyl-chromone-5,7-diol 7-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (1). The six known flavonol glycosides were designated as compounds 2–5, being kaempferol-type glycosides, and compounds 6 and 7, being quercetin-type glycosides. The structures of these glycosides were determined by two-dimensional nuclear magnetic resonance (2D NMR) spectroscopic analysis and chemical evidence.     

New flavonol glycosides from leaves ofSymplocarpus renifolius

A study was carried out to evaluate flavonol glycosides in leaves ofSymplocarpus renifolius (Araceae). From the water fraction of the MeOH extract, three new flavonol glycosides were isolated along with three known compounds, kaempferol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, quercetin-3-O-β-D-glucopyranosy-l-(1→2)-β-D-glucopyranoside, and caffeic acid. The structures of the new flavonol glycosides were elucidated by chemical and spectral analyses as quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, isorhamnetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, and quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-(6^IIII-trans-caffeoyl)-β-D-glucopyranoside.     

Anti-oxidative and inhibitory activities on nitric oxide (NO) and prostaglandin E<Subscript>2</Subscript> (COX-2) production of flavonoids from seeds of <Emphasis Type="Italic">Prunus tomentosa</Emphasis> Thunberg

Chemical investigation of the 80% Me₂CO extract from the seeds of Prunus tomentosa led to the isolation and identification of six flavonoids: kaempferol (1), kaempferol 3-O-α-L-rhamnopyranoside (2; afzelin), kaempferol 3-O-β-D-(6-acetyl)-glucopyranosyl(1→4)-α-L-rhamnopyranoside (3; multiflorin A), kaempferol 3-O-β-D-glucopyranosyl(1→4)-α-L-rhamnopyranoside (4; multiflorin B), quercetin 3-O-α-L-rhamnopyranoside (5; quercitrin), and quercetin 3-O-β-D-glucopyranosyl (1→4)-α-L-rhamnopyranoside (6; multinoside A). Anti-oxidative and inhibitory activities on nitric oxide (NO) and prostaglandin E₂ production in interferon-γ (INF-γ) and lipopolysaccharide (LPS)-activated RAW 264.7 cells in vitro (COX-2) of the isolated compounds were evaluated. Compounds 1, 5, and 6 exhibited potent anti-oxidative activity in the DPPH radical scavenging assay with IC₅₀ values of 57.2, 59.4, and 54.3 μg/mL respectively. The positive control, ascorbic acid, had an IC₅₀ of 55.5 μg/mL. Compounds 1, 5, and 6 also reduced COX-2 levels in a dose dependent manner with IC₅₀ values of 10.2, 8.7, and 9.6 μg/mL respectively, with the positive control, indomethacin, having an IC₅₀ of 5.1 μg/mL. All six compounds inhibited NO production in a dose dependent manner with IC₅₀ values of 35.1, 42.8, 40.0, 44.8, 43.7, and 43.9 μg/mL respectively, while the positive control, L-NMMA, had an IC₅₀ of 42.1 μg/mL.     

Lignan glycosides and flavonoids from <Emphasis Type="Italic">Saraca asoca</Emphasis> with antioxidant activity

Five lignan glycosides, lyoniside, nudiposide, 5-methoxy-9-β-xylopyranosyl-(−)-isolariciresinol, icariside E₃, and schizandriside, and three flavonoids, (−)-epicatechin, epiafzelechin-(4β→8)-epicatechin and procyanidin B₂, together with β-sitosterol glucoside, were isolated from a methyl alcohol (MeOH) extract of Saraca asoca dried bark. Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) and mass spectroscopic analysis. Antioxidant activities were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay.     

A rubrofusarin gentiobioside isomer from roastedCassia tora

From the roasted seeds ofCassia tora L., a new naphthopyrone glycoside was isolated and characterized as 10-[(β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl)oxyl-5-hydroxy-8-methoxy-2-methyl-4H-naphtho [1,2-b]pyran-4-one(isorubrofusarin gentiobioside). Along with isorubrofusarin gentiobioside, alaternin and adenosine were isolated and identified.     

Chemical constituents of the Thai medicinal plant, <Emphasis Type="Italic">Dioecrescis erythroclada</Emphasis> (Kurz) Tirveng

Six compounds were isolated from the leaves and branches of Dioecrescis erythroclada and identified as apodanthoside, mussaenoside, gardenoside, benzyl alcohol O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside, phenethyl alcohol O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside, and oct-1-en-3-ol α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside. The structures were determined based on physical data and spectroscopic evidence.     

Anti-inflammatory phenylpropanoid glycosides from <Emphasis Type="Italic">Clerodendron trichotomum</Emphasis> leaves

The chromatographic separation of MeOH extract from Clerodendron trichotomum Thunberg leaves led to the isolation of three phenylpropanoid compounds. Using spectroscopic methods, the structures of these compounds were determined as β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(4-O-caffeoyl)-glucopyranoside, acteoside (verbascoside) (1), β-(3′, 4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-(6-O-caffeoyl)-glucopyranoside, isoacteoside (2), β-(3′, 4′-dihydroxyphenyl) ethyl-O-α-L-rhamnopyranosyl (1→3)-β-D-glucopyranoside, and decaffeoylacteoside (3). We measured the anti-inflammatory activity of these three phenylpropanoid compounds both in vitro (DPPH Reduction Assay, TBARS Assay on Cu ²⁺-induced oxidized LDL, PGE₂ assay) and in vivo (acetic acidinduced vascular permeability in mice and carrageenan-induced hind paw edema in rats). 80% methanol fraction and acteoside had the activity.     

New triterpenoid saponins from <Emphasis Type="Italic">Argania spinosa</Emphasis>

Five new triterpene saponins, arganine L (1), O (2), P (3), Q (4) and R (5), were isolated from the barks of Argania spinosa (L.) Skeels. Arganines L-P and R are bidesmosidic saponins. The structures of 1–5 were elucidated as 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-apiofuranosyl-(1–3)-β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl] bayogenin, and 3-O-[β-d-apiofuranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, respectively, mainly on the basis of their spectroscopic data.     

A new flavonol glycoside from <Emphasis Type="Italic">Hylomecon vernalis</Emphasis>

Purification of a MeOH extract from the aerial parts of Hylomecon vernalis Maxim. (Papaveraceae) using column chromatography furnished a new acetylated flavonol glycoside (1), together with twenty known phenolic compounds (2–21). Structural elucidation of 1 was based on 1D- and 2D-NMR spectroscopy data analysis to be quercetin 3-O-[4‴-O-acetyl-α-L-arabinopyranosyl]-(1‴→6″)-β-D-galactopyranoside (1). The structures of compounds 2–21 were elucidated by spectroscopy and confirmed by comparison with reported data; quercetin 3-O-[2‴-O-acetyl-α-L-arabinopyranosyl]-(1‴→6″)-β -D-galactopyranoside (2), quercetin 3-O-α-L-arabinopyranosyl-(1‴→6″)-β-D-galactopyranoside (3), quercetin 3-O-β -D-galactopyranoside (4), kaempferol 3,7-O-α-L-dirhamnopyranoside (5), diosmetin 7-O-β -D-glucopyranoside (6), diosmetin 7-O-β -D-xylopyranosyl-(1‴→6″)-β-D-glucopyranoside (7), p-hydroxybenzoic acid (8), protocatechuic acid (9), caffeic acid (10), 6-hydroxy-3,4-dihydro-1-oxo-β -carboline (11), (Z)-3-hexenyl-β -D-glucopyranoside (12), (E)-2-hexenyl-β -D-glucopyranoside (13), (Z)-3-hexenyl-α-Larabinopyranosyl-(1″→6′)-β-D-glucopyranoside (14), oct-1-en-3-yl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (15), benzyl-β-D-apiofuranosyl-(1″→6′)-β-D-glucopyranoside (16), benzyl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (17), benzyl-β-D-xylopyranosyl-(1″→6′)-β-Dglucopyranoside (18), 2-phenylethyl-α-L-arabinopyranosyl-(1″→6′)-β-D-glucopyranoside (19), 2-phenylethyl-β-D-apiofuranosyl-(1″→6′)-β-D-glucopyranoside (20), and aryl-β-D-glucopyranoside (21). Compounds 2-21 were isolated for the first time from this plant. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay.     

Study of constituents of <Emphasis Type="Italic">Veronicastrum villosulum</Emphasis>

We investigated the constituents of Veronicastrum villosulum (Miquel) Yamazaki (Scrophulariaceae), an endangered species belonging to the IA group. From the aerial parts of this plant cultivated at the botanical garden of Sojo University, we isolated two new cucurbitacine-type glycosides, 3-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranosides of 3β,25-dihydroxycucurbit-5,23(E)-diene-7-one-25-methyl ether and 3β,23-dihydroxycucurbit-5,24-diene-7-one-23-methyl ether.