Myricadiol and other taraxerenes from Scaevola spinescens

Scaevola spinescens R. Br. (Goodeniaceae), a West Australian semi-arid native plant, has been found to contain a number of pentacyclic triterpenoid compounds of the taraxerene type in high yield compared with other species in which these compounds are known to occur. Isolation of these molecules, which are potential lead compounds for synthetic anti-cancer drugs, was achieved by partitioning the diethyl ether-soluble fraction, of the methanol Soxhlet extract, between hexane and aqueous methanol, followed by base extraction of minor components from the methanol isolate and recrystallisation or column chromatography. The major component isolated from the extract, and main subject of this report, is the pentacyclic triterpenoid, 14-taraxerene-3,28-diol (1; myricadiol).     

Triterpenoid saponins with neuroprotective effects from the roots of Polygala tenuifolia

The methanol fraction of an ethanolic extract from the roots of Polygala tenuifolia Willd. showed antagonistic action on neurotoxicity induced by glutamate and serum deficiency in PC12 cells. Bioassay-guided fractionation led to the isolation of six new triterpenoid saponins, onjisaponins V - Z, and Vg ( 1 - 6), together with ten known saponins ( 7 - 16). The structures of 1 - 6 were elucidated by spectroscopic and chemical methods. Screening results indicated that compounds 1 - 16 showed neuroprotective effects against serum deficiency and glutamate at the concentration of 10 (-5) mol/L.     

New triterpenoids from the leaves of Cyclocarya paliurus

Six new triterpenoids including four new secodammarane triterpenoid glycosides (1-4), an epoxydammarane triterpenoid glycoside (5), and a new secodammarane triterpenoid (6) were isolated from the ethanolic extract of the leaves of Cyclocarya paliurus. The structures of these compounds were elucidated by spectroscopic analysis methods. Compounds 1-6 were evaluated for their inhibitory activities against α-glucosidase, lipase, DPP-IV, and aldose reductase.     

Isotamarixen - a new antioxidant and prolyl endopeptidase-inhibiting triterpenoid from Tamarix hispida

A new pentacyclic triterpenoid, 3alpha-(3",4"-dihydroxy- trans-cinnamoyloxy)- D-friedoolean-14-en-28-oic acid ( 1) has been isolated along with two known compounds, rhamnocitrin ( 2) and isorhamnetin ( 3) from the aerial parts of Tamarix hispida Willd. Compound 1 was found to be a potent antioxidant. In addition, compounds 1 - 3 showed significant inhibitory activity against prolylendopeptidase (PEP).     

Three new saponins from the leaves of Ilex hylonoma

Three new triterpenoid saponins, hylonosides III-V (1-3) have been isolated, along with three known oleanolic acid saponins (4-6), from the methanol extract of leaves of Ilex hylonoma. The structures were elucidated using a combination of homo- and hetero-nuclear 2D NMR techniques (COSY, TOCSY, NOESY, HMQC and HMBC) and negative FAB-MS. The new compounds were characterized as 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucuronopyranosyl siaresinolic acid-28-O-beta-D-glucopyranosyl ester (1), 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucuronopyranosyl siaresinolic acid-28-O-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucuronopyranosyl oleanolic acid-28-O-beta-D-glucopyranosyl ester (3).     

Paeciloxanthone, a new cytotoxic xanthone from the marine mangrove fungus Paecilomyces sp. (Tree1-7)

The metatrophic fungus Paecilomyces sp. (Tree1-7) was isolated from an estuarine mangrove from the Taiwan Strait. The methanol extract of the fungal mycelium exhibited cytotoxicity against hepG2. Paeciloxanthone (1), a new xanthone, and the known compounds emodin (2) and chrysophanol (3), were isolated from the extract. Their structures were elucidated by spectroscopic experiments. Paeciloxanthone (1) exhibited in vitro cytotoxicity against hepG2 (IC(50)=1.08 microg/mL), acetylcholineesterase (AChE) inhibitory (IC(50)=2.25 microg/mL) and antimicrobial activities.     

Monoamine oxidase inhibitory components from the roots ofSophora flavescens

In our search for monoamine oxidase (MAO) inhibitors from natural resources, we found that the methanol extract of the roots of Sophora flavescens showed an inhibitory effect on mouse brain monoamine oxidase (MAO). Bioactivity-guided isolation of the extract yielded two known flavonoids, formononetin (1) and kushenol F (2), as active compounds along with three inactive compounds, oxymatrine (3), trifolirhizin (4), and beta-sitosterol (5). Formononetin (1) and kushenol F (2) showed significant inhibitory effects on MAO in a dose-dependent manner with IC50 values of 13.2 and 69.9 microM, respectively. Formononetin (1) showed a slightly more potent inhibitory effect against MAO-B (IC50: 11.0 microM) than MAO-A (IC50: 21.2 microM). Kushenol F (2) also preferentially inhibited the MAO-B activity than MAO-A activity with the IC50 values of 63.1 and 103.7 microM, respectively.     

Three new triterpenoid saponins from the rhizomes of Impatiens pritzellii var. hupehensis

Three new triterpenoid saponins, impatiprins A-C (1-3), together with a known triterpenoid (4) and two known triterpenoid saponins (5, 6), were isolated from the rhizomes of Impatiens pritzellii Hook. f. var. hupehensis Hook. f. The structures of 1-3 were determined by 1D and 2D NMR, FAB-MS techniques and chemical methods. Compounds 1 and 2 showed weak cytotoxicities against S-180, HeLa and HepG2 cell lines.     

Anti-complementary activity of ursane-type triterpenoids from Weigela subsessilis

A new ursane-type triterpenoid, weigelic acid (1), and seven known compounds, ursolic acid (2), ilekudinol A (3), corosolic acid (4), ilekudinol B (5), esculentic acid (6), pomolic acid (7), and asiatic acid (8) were isolated from the leaf and stem of Weigela subsessilis. The structure of the new triterpenoid was established as 1beta,2alpha,3alpha,23-tetrahydroxyurs-12-en-28-oic acid on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their anti-complement activity against the classical pathway of the complement system. Of these, compounds 1-2 and 4-8 exhibited anti-complement activity with IC50 values of 152, 90, 130, 51, 56, 4, and 163 microM, respectively, whereas 3 was inactive. This shows that a carboxylic group of ursane-type triterpenoids seems to play an important role in inhibiting the hemolytic activity of human serum against erythrocytes.     

Antimicrobial activity of oleanolic acid from Salvia officinalis and related compounds on vancomycin-resistant enterococci (VRE)

An extract from Salvia officinalis (Sage) leaves showed antimicrobial activity against vancomycin-resistant enterococci (VRE). We isolated the effective compound and identified it as oleanolic acid, a triterpenoid. We also tested antimicrobial activity of similar triterpenoids, ursolic acid, uvaol, betulinic acid and betulin. We found that ursolic acid also showed antimicrobial activity against VRE. The minimum inhibitory concentrations (MICs) of oleanolic acid and ursolic acid were 8 and 4 microg/ml, respectively. These two compounds also showed antimicrobial activity against Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA). These compounds showed bactericidal activity against VRE at least for 48 h when added at concentrations that were two-times higher than their MICs.     

Antioxidant effect ofSalvia miltiorrhiza

A strong antioxidant activity, which was measured by the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, was detected in the methanol extract ofSalvia miltiorrhiza Bunge (Labiatae). By activity-directed fractionation, compounds 1 and 2 were isolated as antioxidant principles ofS. miltiorrhiza. Compounds 1 and 2 were identified as dimethyl lithospermate and 3-(3,4-dihydroxyphenyl)lactamide, respectively, on the basis of spectral data. The radical scavenging effect of compounds 1 and 2 on DPPH radical exceeded that of L-ascorbic acid which is a well known antioxidant. These two compounds also showed prominent inhibitory activity against free radical generation in dichlorofluorescein (DCF) method and cytoprotective effect againstt-BHP in cultured liver cell.     

Paeciloxanthone, a new cytotoxic xanthone from the marine mangrove fungus Paecilomyces sp. (Tree1-7)

The metatrophic fungus Paecilomyces sp. (Tree1-7) was isolated from an estuarine mangrove from the Taiwan Strait. The methanol extract of the fungal mycelium exhibited cytotoxicity against hepG2. Paeciloxanthone (1), a new xanthone, and the known compounds emodin (2) and chrysophanol (3), were isolated from the extract. Their structures were elucidated by spectroscopic experiments. Paeciloxanthone (1) exhibited in vitro cytotoxicity against hepG2 (IC₅₀ = 1.08 μg/mL), acetylcholineesterase (AChE) inhibitory (IC₅₀ = 2.25 μg/mL) and antimicrobial activities.     

Isolation from Cussonia barteri of 1'-O-chlorogenoylchlorogenic acid and 1'-O-chlorogenoylneochlorogenic acid, a new type of quinic acid esters.

1'-O-Chlorogenoylchlorogenic acid and 1'-O-chlorogenoylneochlorogenic acid, a new type of quinic acid esters, have been isolated, in addition to six known quinic acid esters, rutin, and a mixture of saponins, from the methanol extract of Cussonia barteri Seemann (Araliaceae) leaves collected in Cameroon. Structure determination was achieved by NMR, mass, IR, and UV spectroscopy. All compounds were tested for inhibitory activity on 5-lipoxygenase and cyclooxygenase-1, for antimicrobial activity against Bacillus subtilis, Pseudomonas fluorescens, and Cladosporium cucumerinum, and for haemolytic activity.     

Constituents from Limonia Crenulata

A new indole alkaloid, crenulatine (1), along with twenty known compounds, was isolated from the stems of Limonia Crenulata. Their structures were identified by spectral means. Those compounds include four alkaloids, four coumarins, two flavanones, three tetranortriterpenoids, one triterpenoid, three steroids, two lignans and two aromatic compounds.     

Identification of an anti-inflammatory principle from the stem bark of Millettia versicolor

The dichloromethane-soluble fraction of the methanol extract of the stem bark of Millettia versicolor Welw. (Leguminosae) has been shown to possess anti-inflammatory activity. The chromatographic fractionation and subsequent analysis of the spectroscopic data of this extract led to the isolation and identification of 2-acetyl-7-methoxynaphtho[2,3- b]furan-4,9-quinone (1) along with two known quinones. Pharmacological data demonstrate that compound 1 has relevant anti-inflammatory properties whereas the other two isolated compounds do not.     

A new 1,2-diketone physalin isolated from Physalis minima and TRAIL-resistance overcoming activity of physalins

Journal of Natural Medicines - A new 1,2-diketone physalin, physalin XII (1), and 13 known compounds were isolated from the methanol extract of Physalis minima whole plant collected in Thailand....     

Three new triterpenoid saponins from the rhizomes of Impatiens pritzellii var. hupehensis

Three new triterpenoid saponins, impatiprins A-C (1-3), together with a known triterpenoid (4) and two known triterpenoid saponins (5, 6), were isolated from the rhizomes of Impatiens pritzellii Hook. f. var. hupehensis Hook. f. The structures of 1-3 were determined by 1D and 2D NMR, FAB-MS techniques and chemical methods. Compounds 1 and 2 showed weak cytotoxicities against S-180, HeLa and HepG2 cell lines.     

Triterpenoid saponins from Androsace umbellata and their anti-proliferative activities in human hepatoma cells

Two new triterpenoid saponins, along with five known ones, were isolated from the EtOH extract of the whole plants of Androsace umbellata. The structures of the new triterpenoid saponins were identified as 3- O-[ beta- D-xylopyranosyl-(1-->2)- beta- D-glucopyranosyl-(1-->4)-[ beta- D-glucopyranosyl-(1-->2)]- alpha- L-arabinopyranosyl]-3 beta-hydroxy-13 beta,28-epoxy-16-oxo-oleanan-30-al ( 1) and 3- O- beta- D-xylopyranosyl-(1-->2)- beta- D-glucopyranosyl-(1-->4)- alpha- L-arabinopyranosyl-3 beta-hydroxy-13 beta,28-epoxy-16-oxo-oleanan-30-al ( 2) on the basis of their spectral and chemical properties. All these compounds showed significant cytotoxic activities in human hepatoma cells.     

New cytotoxic 6-oxygenated 8,9-dihydrofurocoumarins, hedyotiscone A - C, from Hedyotis biflora

Using the bioactivity-guided fractionation method, three new 6-oxygenated 8,9-dihydrofurocoumarin-type compounds, hedyotiscones A, B, and C were isolated from the methanol extract of Hedyotis biflora together with seven known compounds. The structures of all isolated compounds were determined on the basis of mass and spectroscopic evidence. Compounds, oleanolic acid, and 6'-(beta-sitosteryl-3- O-beta- D-glucopyranosidyl) pentadecanoate showed marginal cytotoxicity against Hep G2 cells (human liver cancer cells) with IC50 values of 14.4, 17.4, 4.9, 8.0, and 9.2 microg/mL, respectively. Ursolic acid showed significant cytotoxicity against MDA-MB-231 cells (human breast carcinoma cells) with an IC50 value of 1.49 microg/mL.