Triterpene glycosides from red ginseng marc and their anti-inflammatory activities

Three new triterpene glycosides ursan-3β,19α,22β-triol-3-O-β-d-glucopyranosyl (2′→1″)-β-d-glucopyranoside (1), ursan-3α,11β-diol-3-O-α-d-glucopyranosyl-(6′→1″)-α-d-glucopyranosyl-(6″→1‴)-α-d-glucopyranosyl-(6‴→1‴′)-α-d-glucopyranoside (2) and lanost-5,24-dien-3β-ol-3-O-β-d-glucopyranosyl-(6′→1″)-β-d-glucopyranosyl-(6″→1‴)-β-d-glucopyranoside (3), together with one known compound were isolated and identified from the marc of red ginseng. Their structures were elucidated by spectroscopic data analysis. Compounds (1–3) were investigated for anti-inflammatory effects using the RAW 264.7 macrophage cell line. In the cell proliferation assay, lipopolysaccharide stimulation decreased cell proliferation of RAW 264.7 macrophage cells, but the suppression of cell proliferation was significantly protected by treatment with compounds 2 and 3. Compounds 2 and 3 had a suppressive effect on the production of nitric oxide (NO), and they inhibited mRNA expression of proinflammatory mediators such as inducible nitric oxide synthase, and cyclooxygenase-2, and proinflammatory cytokines such as two interleukins and tumor necrosis factor-α. These findings suggest that compounds 2 and 3 have potential anti-inflammatory activities.     

Flavonol glycosides of Warburgia ugandensis leaves

Four new flavonol gycosides: kaempferide 3-O-beta-xylosyl (1-->2)-beta-glucoside, kaempferol 3-O-alpha-rhamnoside-7,4'-di-O-beta-galactoside, kaempferol 3,7,4'-tri-O-beta-glucoside and quercetin 3-O-[alpha-rhamnosyl (1-->6)] [beta-glucosyl (1-->2)]-beta-glucoside-7-O-alpha-rhamnoside, were characterized from a methanolic leaf extract of Warburgia ugandensis. The known flavonols: kaempferol, kaempferol 3-rhamnoside, kaempferol 3-rutinoside, myricetin, quercetin 3-rhamnoside, kaempferol 3-arabinoside, quercetin 3-glucoside, quercetin, kaempferol 3-rhamnoside-4'-galactoside, myricetin 3-galactoside and kaempferol 3-glucoside were also isolated. Structures were established by spectroscopic and chemical methods and by comparison with authentic samples.     

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.     

Flavonol and drimane-type sesquiterpene glycosides of Warburgia stuhlmannii leaves

An investigation of methanolic extract of Warburgia stuhlmannii leaves has led to the isolation of two new drimane-type sesquiterpene glycosides characterized as mukaadial 6-O-beta-D-glucopyranoside, mukaadial 6-O-alpha-L-rhamnopyranoside together with two other novel flavonol glycosides identified as 3',5'-O-dimethylmyricetin 3-O-beta-D-2",3"-diacetylglucopyranoside and 3'-O-methylquercetin 3-O-beta-D-2",3",4"-triacetylglucopyranoside. The known compounds; mukaadial, deacetylugandensolide, quercetin, kaempferol, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-beta-D-glucopyranoside, kaempferol 7-O-beta-D-glucopyranoside, myricetin 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-sophoroside and isorhamnetin 3-O-beta-D-glucopyranoside were also isolated from the same extract.     

Flavonol glycosides from Asplenium bulbiferum

From aerial parts of the fern Asplenium bulbiferum, besides kaempferol 3,7-diglucoside and kaempferol 3-O-rhamnoside- 7-O-glucoside, the new glycoside kaempferol 3-O-β-glucoside-7-O-β-galactoside has been characterized.     

Flavonol glycosides from Anthyllis onobrychioides

A new flavonol glycoside, rhamnocitrin 3-O-β-D-galactopyranoside, has been isolated from aerial parts of Anthyllis onobrychioides, together with the known 3-O-β-D-galactopyranosides of quercetin, isorhamnetin and kaempferol.     

Phenylethaniod glycosides from Orobanche pycnostachya Hance and their chemotaxonomic significance

In this current study, we investigated the chemical ingredients of the whole plants of Orobanche pycnostachya Hance. Eighteen compounds, including fifteen phenylethaniod glycosides (2–16), two lignans (17, 18), and one flavonoid (1) were obtained from this plant and they were elucidated utilizing spectroscopic methods. This is the first study to describe the isolation of compounds 1-5, 7–11, 13, and 15–18 from O. pycnostachya and compound 2, 4, 7, and 9 from the genus Orobanche L.     

Cytotoxic and anti-inflammatory salicin glycosides from leaves of Salix acmophylla

The species of genus Salix, commonly known as Willow, are well known worldwide as rich source of medicinally important salicin derivatives and phenolic glycosides. The current study focuses on Salix acmophylla Bioss with the aim of identifying new bioactive constituents of this plant. Two new salicin glycosides, acmophyllin A (1), acmophyllin B (2) and five reported phenolic glycosides 3⿿7, were identified from S. acmophylla Bioss. NMR and mass spectroscopic techniques were employed to elucidate the structure of secondary metabolites of S. acmophylla. The new salicin glycosides were evaluated against three different cancer cell lines i.e., PSN-1 (pancreatic cancer cells), MCF-7 (breast cancer cells) and NCI-H460 (lung cancer cells). The acmophyllin A (1) exhibited cytotoxicity in a dose dependent manner against all three cancer cells (IC₅₀ ⿼35⿿40 μM). Acmophyllin B (2) exhibited mild activity against PSN-1 cells and MCF-7 cancer cells. In addition, compounds 5 and 6 showed potent inhibition of oxidative burst in zymosan activated neutrophils by chemiluminescence technique, while no other compound were found to inhibit the production of reactive oxygen species (ROS).     

Two new flavonoid glycosides from Iris tectorum

Phytochemical investigation of the ethanol extract of rhizomes of Iris tectorum resulted in the isolation and characterization of two new flavonoid glycosides, tectorigenin-7-O-β-d-fucopyranoside (1), 3,5,4′-trihydroxy-7,3′-dimethoxyflavanone-5-O-α-l-rhamnopyranoside (2), together with two known ones (3, 4). The rhamnose substituent at C-5 displayed uncommon connection in naturally occurring flavonoid glycosides. Their structures were elucidated on the basis of extensive spectroscopic analysis. All of the isolates were evaluated for their in vitro inhibitory activity against aldose reductase.     

The biosynthesis of flavonoid glycosides and their importance in chemosystematics

The present article reviews flavonoid O-glycosyltransferases with respect to the historical background, isolation and purification methods, properties of the enzymes involved (especially substrate specificities) and genetic control. The possible biosynthetic pathway leading to the formation of C-glycosides is also discussed. The second part of the article is an attempt to indicate the importance of glycosylation patterns in the field of chemosystematics, especially on the intra- and infra-specific levels. The position and nature of glycosylation are first discussed, and this is followed by examples indicating the importance of glycosylation patterns.     

Phenylethanoid and secoiridoid glycosides from the leaves of Ligustrum purpurascens

A new phenylethanoid glycoside (2) and a new secoiridoid glycoside (16) were isolated from the leaves of Ligustrum purpurascens together with fourteen known compounds (1 and 3–15). The structures of the new compounds were determined by spectroscopic analyses (UV, IR, HR-ESI-MS, 1D, and 2D NMR). The absolute configuration of 16 was further determined by CD analysis. All phenylethanoid glycosides were prepared and their up-regulation of IFN-γ production in mouse splenic lymphocytes was evaluated. Compounds 1, 5, 6, 10, 11, 13 and 15 exhibited potent stimulatory effect on IFN-γ secretion.     

Three new flavonoid glycosides from the aerial parts of Graptophyllum grandulosum Turril (Acanthaceae)

Grandulosides A-C, three new flavonoid glycosides, were isolated from the aerial parts of Graptophyllum grandulosum Turill and identified as chrysoeriol-7-O-β-d-apiofuranosyl-(1 → 2)-β-d-xylopyranoside (1), chrysoeriol-7-O-[4′′′-O-acetyl-β-d-apiofuranosyl-(1 → 2)]-β-d-xylopyranoside (2) and 7-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-(4′′-Sodium hydrogeno sulfate) glucopyranoside (3). Four known compounds, chrysoeriol-7-O-β-d-xyloside (4), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside (5), luteolin-7-O-β-d-apiofuranosyl-(1 → 2)-β-d-xylopyranoside (6) and sucrose (7) were also obtained. The structures of these compounds were established by interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (¹H, ¹³C) and 2D-NMR (COSY, NOESY, HSQC and HMBC) and by comparison with the literature data.     

New phenanthrene glycosides from Dendrobium denneanum and their cytotoxic activity

Five new phenanthrene glycosides, denneanosides A–E (1–5), and one new 9,10-dihydrophenanthrene glycoside, denneanoside F (6) were isolated from the stem of Dendrobium denneanum. The chemical structures of the new compounds were established on the basis of extensive spectroscopic data. The isolated compounds were evaluated for their in vitro cytotoxic activity against SNU387 hepatocellular carcinoma cell line. Compounds 1–3 showed moderate cytotoxic activities while compounds 4–6 showed weak activities.     

Flavonol glycosides from Securidaca diversifolia

Twelve flavonol glycosides have been isolated from the leaves of Securidaca diversifolia. The separation of ten quercetin 3-glycosides and two kaempferol 3-glycosides was achieved by droplet counter-current chromatography (DCCC), preparative reversed-phase chromatography and gel chromatography. The structures were established on the basis of partial and total acid hydrolysis and spectral data (UV, ¹³C NMR, FAB, MS, D/CI MS). The four apiosides: quercetin 3-(2″-β-D-apiofuranosyl-β-D-glucopyranoside), 3-(2″-β-D-apiofuranosyl-β-D-galactoside), 3-(2″-β-D-apiofuranosyl-α-L-arabinopyranoside) and 3-(2″-β-D-apiofuranosyl-β-D-xylopyranoside) are new natural products. The structure of kaempferol 3-(2″-β-D-apiofuranosyl-β-D-glucopyranoside), previously isolated from Cicer arietinum, is confirmed.     

Lignan glycosides from the Rhizomes of Smilax trinervula and their Biological activities

Phytochemical investigation of the rhizomes of Smilax trinervula led to isolation and structure elucidation of eight lignan glycosides, including five new lignans, namely, (7S, 8R, 8′R)-4, 4′, 9-trihydroxy-3, 3′, 5, 5′-tetramethoxy-7, 9′-epoxylignan-7′-one 4′-O-β-d-glucopyranoside (1), (7S, 8R, 8′R)-4, 4′, 9-trihydroxy-3, 3′, 5, 5′-tetramethoxy-7, 9′-epoxylignan-7′-one 4-O-β-d- glucopyranoside (2) (7S, 8R)-4, 9, 9′-trihydroxy-3, 3′, 5-trimethoxy-4′, 7-epoxy-8, 5′-neolignan 9′-O-β-d-glucopyranoside (3), (7R, 8R)-4, 9, 9′-trihydroxy-3, 5-dimethoxy-7.O.4′, 8.O.3′- neolignan 9′-O-β-d-glucopyranoside (4), and (7S, 8R)-4, 9, 9′-trihydroxy-3, 3′, 5-trimethoxy-8, 4′-oxy-neolignan 4-O-β-d-glucopyranoside (5), along with three known compounds (6-8). Their structures were established mainly on the basis of 1D and 2D NMR spectral data, ESI–MS and comparison with the literature. Compounds 1-8 were tested in vitro for their cytotoxic activity against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, Lovo). Compounds 3 and 5 exhibited cytotoxic activity against Lovo cells, with IC₅₀ value of 10.4 μM and 8.5 μM, respectively.     

New iridoid glycosides from the fruits of Forsythia suspensa and their hepatoprotective activities

A novel iridoid glycoside trimer named forsydoitriside A (1) and five new iridoid glycosides (2–6) were isolated from the fruits of Forsythia suspensa together with two known compounds (7, 8). These new structures were elucidated by comprehensive spectroscopic data and the comparison of experimental and calculated electronic circular dichroism spectra. Compounds 1–8 were all assayed on acetaminophen-induced HepG2 cell damage. The results exhibited that compounds 2, 3, 5 and 6 possessed strong hepatoprotective activities against the damage in HepG2 cell.     

Flavonol glycosides in the leaves ofTrillium apetalon Makino andT. kamtschaticum pallas

Seven flavonol glycosides were isolated from the leaves ofT. apetalon. They were identified chromatographically and spectrally to be: quercetin/kaempferol 3-O-α-arabinopyranosyl-(1→6)-β-galactopyranoside (TQ and TK), quercetin/kaempferol 3-O-[2‴-O-acetyl-α-arabinopyranosyl]-(1→6)-β-galactopyranoside (TAQ and TAK), quercetin 3-O-β-glucoside (ISQ), isorhamnetin 3-O-α-arabinopyranosyl-(1→6)-β-galactopyranoside (TI) and isorhamnetin 3-O-[2‴-O-acetyl-α-arabinopyranosyl]-(1→6)-β-galactopyranoside (TAI). TQ, TAQ, TI and TAI were major constituents. This is the first report on two new isorhamnetin-type glycosides, TI and TAI. The seven flavonol glycosides identical to those ofT. apetalon were isolated and identified in the leaves ofT. kamtschaticum; TQ and TAQ were also major components, but TI and TAI were only minor components. TI and TAI were not detected in the leaves ofT. tschonoskii. These leaf-flavonoid patterns were discussed from a chemosystematic point of view. Part 3 in the series “Studies of the flavonoids of the genusTrillium”. For Part 2 see Yoshitamaet al., (1997) J. Plant Res.110: 379–381.