New bioactive macrocyclic diterpenoids from Jatropha multifida

Two new macrocyclic diterpenoids, multifidanol (1) and multifidenol (2) along with several known compounds have been isolated from the stem of Jatropha multifida. The structures of the new compounds were established from the extensive studies of their 1D and 2D NMR spectra. The cytotoxic and antimicrobial activities of these two constituents were examined.     

Antifeedant neo-clerodanes from Teucrium tomentosum Heyne. (Labiatae)

From the acetone extract of Teucrium tomentosum, a new antifeedant neo-clerodane diterpenoid teuctosin (1) was isolated along with teuflin (2), teucrin-H(2) (3), 6beta-hydroxyteuscordin (4), 6beta-acetylteuscordin (5) and montanin-D (6). The structure of the new compound was elucidated comprehensively using 1D and 2D NMR methods and confirmed by X-ray crystallography. All the compounds showed effective antifeedancy against Plutella xylostella and Spodoptera litura at 10 mug/cm(2) of leaf area.     

Flavanoids from Caesalpinia pulcherrima

Two new flavanoids, 5,7-dimethoxy-3',4'-methylenedioxyflavanone and isobonducellin along with 2'-hydroxy-2,3,4',6'-tetramethoxychalcone, 5,7-dimethoxyflavone and bonducellin were isolated from the aerial parts of Caesalpinia pulcherrima. The structures of the compounds were settled mainly by interpretation of their 1D and 2D NMR spectra. Isobonducellin was found to be a homoisoflavanoid containing a cis (Z)-double bond. Antimicrobial activity of the new compounds was evaluated.     

Diterpenoid quinones from rosemary (Rosmarinus officinalis L.)

Two new abietane-type diterpenoid o-quinones, 7beta-methoxyabieta-8,13-diene-11,12-dione-(20,6beta)-olide (rosmaquinone A) (1) and 7alpha-methoxyabieta-8,13-diene-11,12-dione-(20,6beta)-olide (rosmaquinone B) (2), together with six known compounds were isolated from the aerial parts of Rosmarinus officinalis L. The structures of the new compounds were determined by extensive spectroscopic analysis, including IR, UV, HR-EIMS, 1D and 2D 400 MHz NMR data (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOEs).     

Ent-pimarane type diterpenes from Gnaphalium gaudichaudianum

Fractionation of the methanol extract of Gnaphalium gaudichaudianum DC afforded one new and six known ent-pimarane diterpenes together with velutin, squalene and stigmasterol. The structure of the new compound was established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. Two of the isolated compounds exhibited moderate toxicity in the Artemia salina toxicity test.     

A new ecdysteroid with unique 9beta-OH and four other ecdysteroids from Silene italica ssp. nemoralis

A new natural ecdysteroid, 9beta,20-dihydroxyecdysone (1) and four related compounds 5alpha-20-hydroxyecdysone (2), 5alpha-2-deoxy-integristerone A (3), integristerone A (4) and 22-deoxy-integristerone A (5) were isolated from the herb of Silene italica ssp. nemoralis. Compound 1 is the C-9 epimer of the known 9alpha,20-dihydroxyecdysone (6) and represents a peculiar steroid skeleton. The structures of the compounds were elucidated by 1D and 2D NMR, IR and MS spectroscopy.     

A guaianolide alloside and other constituents from Picris kamtschatica

From Picris kamtschatica two new guaianolide glycosides, including a beta-allopyranosyl analogue of ixerin F, were isolated, in addition to ten known sesquiterpene lactones and six phenolic compounds. This is the first time a sesquiterpene lactone alloside has been described from plants. The compounds were characterized based on mass, 1D and 2D NMR spectral data.     

Isolation and structure determination of triterpenes from Iris tectorum

Four iridal-type triterpenoids, two of which were new compounds, have been isolated from rhizomes of Iris tectorum Maxim. Their structures were determined by 1D and 2D NMR spectroscopy and ESI-MS spectrometry. The compounds were identified as the iritectols A and B, and the known iridobelamal A and isoiridogermanal. The presence of epoxide and tetrahydrofuran functions are not common in previously isolated iridal-type triterpenoids.     

Flavonoid glycosides from Salvia moorcroftiana wall

Phytochemical analysis of the whole plant of Salvia moorcroftiana Wall. (Lamiaceae) resulted in the isolation of two new flavonoid glycosides, together with three known compounds. The structures of the new compounds were established as genkwanin 4'-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-galactopyranoside (1) and genkwanin 4'-O-[alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-galactopyranoside] (2). The structures of all compounds were elucidated by spectroscopic methods, including 2D NMR techniques.     

Two ellagitannins from Punica granatum heartwood

In the course of studies on polyphenol metabolism in Punica granatum heartwood two new ellagitannins, diellagic acid rhamnosyl (1-->4) glucopyranoside and 5-O-galloylpunicacortein D were isolated and characterized together with four known tannin metabolites, punicacortein D, punicalin, punicalagin and 2-O-galloylpunicalin. Structures of the isolated compounds were established by chromatography, chemical degradation, UV and 1D/ 2D 1H/13C NMR spectroscopy.     

Coumaroyl triterpene lactone, phenolic and naphthalene glycoside from stem bark of Diospyros angustifolia

From the ethanolic extract of stem bark of D. angustifolia three new compounds, a coumaroyl triterpene lactone, diospyrosooleanolide (1), a phenolic glycoside, diospyrososide (2) and a naphthalene glycoside, diospyrosonaphthoside (3) were isolated along with five known compounds (4-8). The structures of these compounds were established on the basis of spectroscopic and chemical evidences.     

Cycloartane type triterpenoids from the rhizomes of Polygonum bistorta

Two new compounds, 24(E)-ethylidenecycloartanone (1) and 24(E)-ethylidenecycloartan-3alpha-ol (2) were isolated from the rhizomes of Polygonum bistorta, together with seven known compounds viz., cycloartane-3,24-dione (3), 24-methylenecycloartanone (4), gamma-sitosterol (5), beta-sitosterol (6), beta-sitosterone (7), friedelin (8) and 3beta-friedelinol (9). All the cycloartane type triterpenoids, compounds 7 and 8 are reported for the first time from this plant. A combination of 1D and 2D NMR spectroscopy and MS were mainly used to elucidate the structures of the new compounds 1 and 2.     

Flavonoids and terpenoids from Helichrysum forskahlii

Three new flavonoids, namely helichrysone A (1), helichrysone B (2) and helichrysone C (3) were isolated from the aerial parts of Helichrysum forskahlii, together with 10 known flavonoids, three triterpenes, and one sesquiterpene. The structures of the new flavonoids 1-3 were established by 1D and 2D NMR spectral data. In addition, the antimicrobial activities of the isolated compounds were determined.     

Triterpenoid saponins from Pteleopsis suberosa stem bark

Thirteen oleanane saponins (1-13), four of which were new compounds (1-4), were isolated from Pteleopsis suberosa Engl. et Diels stem bark (Combretaceae). Their structures were determined by 1D and 2D NMR spectroscopy and ESI-MS spectrometry. The compounds were identified as 2alpha,3beta,19alpha,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (1), 2alpha,3beta,19beta,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha,23-tetrahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (3), and 2alpha,3beta,6beta,19alpha,24-pentahydroxy-11-oxo-olean-12- en-28-oic acid 28-O-beta-D-glucopyranosyl ester (4). The presence of alpha,beta-unsaturated carbonyl function was not common in the oleanane class and the aglycons of these compounds were not found previously in the literature. Moreover, the isolated compounds were tested against Helicobacter pylori standard and vacA, and cagA clinical virulence genotypes. Results showed that compound 6 has an anti-H. pylori activity against three metronidazole-resistant strains (Ci 1 cagA, Ci 2 vacA, and Ci 3).     

Tyrosine kinase inhibitors from the rainforest tree Polyscias murrayi

A series of 3-(4-hydroxyphenyl) propanoic acid derivatives, which inhibit Itk (interleukin-2 inducible T-cell kinase), a Th2-cell target, were isolated from the Australian rainforest tree Polyscias murrayi. The new compound 3-(4-hydroxyphenyl) propionyl choline and a 2:1 mixture of the new compounds 3,4-di-O-3-(4-hydroxyphenyl) propionyl-1,5-dihydroxycyclohexanecarboxylic acid and 3,5-di-O-3-(4-hydroxyphenyl) propionyl-1,4-dihydroxycyclohexanecarboxylic acid were isolated along with two known compounds 3-(4-hydroxyphenyl) propanoic acid and 3-(3,4-hydroxyphenyl) propanoic acid. Their structures were determined by 1D and 2D NMR spectroscopy. The assay results suggest that both the 3-(4-hydroxyphenyl) propanoate and carboxyl moieties contribute to Itk activity of the compounds.     

Chalcones and other constituents of Dorstenia prorepens and Dorstenia zenkeri

The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,3'-(3,7-dimethyl-2,6-octadienyl)-3,4, 2',4'-tetrahydroxychalcone while Dorstenia zenkeri yielded the 3',4'-(3-hydroxy-2,2-dimethyldihydropyrano)-4,2'-dihydroxychalcone and a bichalcone. 4-Hydroxylonchocarpin was found in both plants. D. prorepens also yielded the known compounds: psoralen, bergapten, beta-sitosterol and its D-glucopyranosyl derivative. D. zenkeri yielded p-hydroxybenzaldehyde, dorsmanin A, 4,2',4'-trihydroxychalcone and 4,2',4'-trihydroxy-3'-prenylchalcone. Structures of the new compounds were established by UV, IR, MS and 2-D NMR analysis.     

Flavones from Andrographis viscosula

Two new 2'-oxygenated flavones, 5,7,2'-trimethoxyflavone (1). and 5,7,2',4',6'-pentamethoxyflavone (2). were isolated from the whole plant of Andrographis viscosula along with three known flavones, echioidinin (3). 5,2',6'-trihydroxy-7-methoxyflavone (4). and echioidin (5). The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectral studies.     

Benzoquinone derivatives of Myrsine africana and Maesa lanceolata

The fruits of Myrsine africana afforded two new benzoquinone derivatives, methylvilangin and methylanhydrovilangin. On the other hand, from the fruits of Maesa lanceolata two more novel compounds; 2,5-dihydroxy-3-(nonadec-14-enyl)-benzoquinone and lanciaquinone were isolated. Their structural elucidation was achieved by spectroscopic measurements including 2D NMR experiments.     

Constituents of the stems of Macrococculus pomiferus and their inhibitory activities against cyclooxygenases-1 and -2

As part of our program directed towards the discovery of new cancer chemopreventive agents from plants, the EtOAc-soluble extract of the stems of M. pomiferus was found to inhibit the enzyme cyclooxygenase-2 (COX-2). Bioassay-directed fractionation of this extract led to the isolation of two dibenzylbutyrolactone lignans, (8R,8'R)-3'-O-demethyl-5-hydroxymatairesinol (1) and (8R,8'R)-3'-O-demethyl-5-methoxymatairesinol (2), as well as seven known compounds, (-)-5'-methoxyyatein (3), blumenol A, (-)-deoxypodophyllotoxin (anthricin), (-)-deoxypodorhizone, 2,6-dimethoxyhydroquinone, 4-hydroxybenzaldehyde, and beta-sitosterol glucoside. The structures of compounds 1 and 2 were determined using spectroscopic data (1D and 2D NMR, and HREIMS), and the 8R and 8'R absolute stereochemistry was established for both 1 and 2 on the basis of their CD spectra. All isolates obtained in the present study were evaluated for their inhibitory effects with both COX-1 and -2. Of these, only 5'-methoxyyatein (3) showed weak activity against COX-2, while all other compounds isolated were inactive. The COX-2 inhibitory activity of the EtOAc extract was also traced to the presence of several common fatty acids by LC-MS.