Furanoflavonoids from Pongamia pinnata fruits

Fruits of Pongamia pinnata afforded four new furanoflavonoids, pongapinnol A-D (1-4), and a new coumestan, pongacoumestan (5) along with thirteen known compounds 6-18. Compounds 16 and 17 are isolated for the first time from this plant. The structures of isolated compounds were elucidated on the basis of spectroscopic data interpretation.     

Furanoflavonoid glycosides from Pongamia pinnata fruits

Pongamia pinnata fruits afforded three new furanoflavonoid glucosides, pongamosides A-C (1-3), and a new flavonol glucoside, pongamoside D (4). The structures of these compounds were established on the basis of spectroscopic studies. This is the first time that furanoflavone glucosides have been found as naturally occurring compounds.     

Chemosystematic investigations of irregular diterpenes in Anisotome and related New Zealand Apiaceae

A chemosystematic HPLC-UV and HPLC-MS investigation of New Zealand members of the Apiaceae was performed. Diterpenes were identified and quantified in methanolic extracts from subaerial parts of 28 taxa and 54 samples of Aciphylla, Anisotome, Apium, Gingidia, Lignocarpa, Oreomyrrhis, and Scandia. Six diterpenes (1-2, 4-7) and four polyacetylenes (8-11) were identified. The known compounds were the diterpenes anisotomenoic acid 1, anisotomene-1-ol 2, 16-acetoxyanisotomenoic acid 4 and anisotomene-1,12-diol 5; and the polyacetylenes falcarinol 8, falcarindiol 9, (+)-9(Z),17-octadecadiene-12,14-diyne-1,11,16-triol 10, and (+)-9(Z),17-octadecadiene-12,14-diyne-1,11,16-triol 1-acetate 11. New irregular diterpenes 13,14-dihydroanisotom-12E-ene-1,14-diol 6 and 14-methoxy-13,14-dihydroanisotom-12E-ene-1-ol 7 were isolated from A. haastii. Isomers of the new semi-synthetic diterpene 16-hydroxyanisotomenoic acid 3 were detected in extracts of Anisitone flexuosa. Structure elucidation was performed by HR mass spectrometry and 1D and 2D NMR spectroscopy. In crude extracts, compounds were identified by their HPLC retention times and their on-line HPLC-UV and MS spectra. Anisotomene diterpenes occurred in eight out of 16 species of the genus Anisotome, but were not detected in any of the other genera. In contrast, polyacetylenes were present in all the genera investigated.     

Inter- and intraspecific variation in defensive compounds produced by five neotropical stink bug species (Hemiptera: Pentatomidae)

The differences in composition of defensive secretions between nymphs, adult males and adult females of Chinavia impicticornis (=Acrosternum impicticorne), Chinavia ubica (=Acrosternum ubicum), Euschistus heros, Dichelops melacanthus and Piezodorus guildinii (Hemiptera, Pentatomidae) were analysed within and between species using compositional log-ratio statistics and canonical variates analysis. Differences in composition between nymphs, males and females were found for all species, as well as when all species were pooled. In particular, tetradecanal appears to be a predominantly nymphal compound in D. melacanthus, E. heros and P. guildinii. In the two Chinavia species 4-oxo-(E)-2-hexenal and an unknown compound were more dominant in nymphs. The interspecific analysis revealed a good separation of defensive compounds according to their taxonomic relationship. Thus, the two Chinavia species grouped together, with (E)-2-decenal and (E)-2-hexenyl acetate, contributing to this separation. The other three species also differed from each other, with (E)-2-octenal associated to D. melacanthus, (E)-2-hexenal to P. guildinii and (E,E)-2,4-decadienal and tetradecanal to E. heros. The pooled analysis of stage ignoring species revealed tetradecanal and 4-oxo-(E)-2-decenal (tentative identification) strongly associated to nymphs. Thus, there are predictable differences between stages, and many of the differences are conserved between species. Consideration of these differences could prove to be important in understanding stink bug-natural enemy interactions, and in optimising biocontrol efforts.     

Leishmanicidal cycloartane-type triterpene glycosides from Astragalus oleifolius

Two new cycloartane-type glycosides oleifoliosides A (1) and B (2) were isolated from the lower stem parts of Astragalus oleifolius. Their structures were identified as 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-xylopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane and 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-glucopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane, respectively, by means of spectroscopic methods (IR, 1D and 2D NMR, ESI-MS). Three known cycloartane glycosides cyclocanthoside E (3), astragaloside II (4) and astragaloside IV (5) were also isolated and characterized. All five compounds were evaluated for in vitro trypanocidal, leishmanicidal and antiplasmodial activities as well as their cytotoxic potential on primary mammalian (L6) cells. Except for the compound 5, all compounds showed notable growth inhibitory activity against Leishmania donovani with IC50 values ranging from 13.2 to 21.3 microg/ml. Only weak activity against Trypanosoma brucei rhodesiense was observed with the known compounds astragaloside II (4, IC50 66.6 microg/ml) and cyclocanthoside E (3, IC50 85.2 microg/ml), while all compounds were inactive against Trypanosoma cruzi and Plasmodium falciparum. None of the compounds were toxic to mammalian cells (IC50's > 90 microg/ml). This is the first report of leishmanicidal and trypanocidal activity of cycloartane-type triterpene glycosides.     

Variations in the concentration of phenolic compounds in the seagrass Posidonia oceanica under conditions of competition

The concentration of phenolic compound was measured in the seagrass Posidonia oceanica when interacting with two Bryopsidophyceae, Caulerpa taxifolia and Caulerpa racemosa, between May 1999 and May 2000. These measurements were performed on adult and intermediate leaves and in sheaths of the seagrass. Sampling was carried out at three stations subject to increasing levels of interaction with Caulerpa. The number of tannin cells was also analysed. Five phenolic compounds were identified in P. oceanica, with a predominance of caffeic acid in the adult and intermediate leaves. For a given level of interaction (and for both caulerpa sp.), a significant seasonal variation in phenolic compounds was shown in the adult leaves (higher in November and lower in September and March for example for the interaction with C. taxifolia). Only for two compounds (corresponding to a mixture containing ferulic acid and the ester methyl 12-acetoxyricinoleate) were significant differences observed as a function of the level of interaction with C. taxifblia, and only in the adult leaves: higher concentrations of phenols were observed with increasing level of interaction. Thus,adult leaves gave values of 55.5 +/- 14.1 microg g(-1) dm without interaction (OCt) and 94.9 +/- 23.4 microg g(-l) dm with high interaction (2Ct),corresponding to an increase of 70%. No significant difference was observed with intermediate leaves and sheaths, or for interaction with C. racemosa. The number of tannin cells (supposed to produce the phenolic compounds) largely increased in the adult and intermediate leaves when the degree of interaction with C. taxifolia increased: 90 mm above the base of the sheath (in adult leaves), 16.7 +/- 10.6 tannin cells cm(-2) were found without interaction (OCt), and 57.8 + 21.2 tannin cells cm(-2) with high interaction (2Ct). No significant difference was found for C. racemosa interaction. It thus appears that when the seagrass P. oceanica is in interaction with C. taxifolia, it accelerates its production of secondary metabolites so as to limit invasion of the beds.     

Volatile components from European liverworts Marsupella emarginata,M. aquatica and M. alpina

The hydrodistillation products of the liverworts Marsupella emarginata, M. aquatica and M. alpina were investigated by spectroscopic methods. A number of new compounds could be isolated by preparative gas chromatography (GC) and identified by spectroscopic techniques including GC-mass spectrometry, NMR and chemical correlations in conjunction with enantioselective GC. From M. emarginata, in addition to many known compounds, the sesquiterpene hydrocarbon (-)-7-epi-eremophila-1(10),8,11-triene (1) and the sesquiterpene derivatives (-)-4-epi-marsupellol (2), (-)-marsupellol acetate (18), (-)-4-epi-marsupellol acetate (4), (+)-5-hydroxymarsupellol acetate (5) and (-)-9-acetoxygymnomitr-8(12)-ene (24) could be identified. In M. aquatica the sesquiterpene hydrocarbons (-)-myltayl-8(12)-ene (7), ent-(+)-amorpha-4,11-diene (8), (-)-amorpha-4,7(11)-diene (9), the sesquiterpene alcohol (+)-9-hydroxyselina-4,11-diene (10) and (-)-2-acetoxyamorpha-4,7(11)-diene (11) were identified. In M. alpina (-)-trans-selina-4(15),11-dien-5-ol (12), (+)-8,9-epoxyselina-4,11-diene (13) and (+)-cis-selina-4(15),11-dien-5-ol (14) were found as new natural products.     

Terpenoids and phenol derivatives from Malva silvestris

A sesquiterpene and a tetrahydroxylated acyclic diterpene as well as two known monoterpenes, 6 C(13)nor-terpenes and 11 aromatic compounds were isolated from the water extract of Malva silvestris. The structures of the compounds were determined by spectroscopic NMR and MS analysis. Effects of these compounds on germination and growth of dicotyledon Lactuca sativa L. (lettuce) were studied in the 10(-4)-10(-7)M concentration range.     

Pongamone A-E, five flavonoids from the stems of a mangrove plant, Pongamia pinnata

Chemical investigation of stems of the mangrove plant, Pongamia pinnata, resulted in isolation and characterization of five structurally unusual flavonoids pongamones A-E, along with 16 known flavonoid metabolites. Their structures were determined on the basis of spectroscopic analyses and by comparison of their spectroscopic data with those of related compounds reported in the literature. Pongamones A-E were assayed against DHBV RCs DNAP and HIV-1 RT in vitro. A possible biogenetic pathway of the isolated compounds is also proposed.     

Anti-protozoal and plasmodial FabI enzyme inhibiting metabolites of Scrophularia lepidota roots

The ethanolic root extract of Scrophularia lepidota, an endemic plant of the Turkish flora, has been investigated for its anti-protozoal and inhibitory effect towards plasmodial enoyl-ACP reductase (FabI), a key enzyme of fatty acid biosynthesis in Plasmodium falciparum. Chromatographic separation of the extract yielded 10 iridoids (1-10), two of which are new, and a known phenylethanoid glycoside (11). The structures of the new compounds were determined as 3,4-dihydro-methylcatalpol (8) and 6-O-[4'-O-trans-(3,4-dimethoxycinnamoyl)-alpha-L-rhamnopyranosyl]aucubin (scrolepidoside, 9) by spectroscopic means. The remaining metabolites were characterized as catalpol (1), 6-O-methylcatalpol (2), aucubin (3), 6-O-alpha-L-rhamnopyranosyl-aucubin (sinuatol, 4), 6-O-beta-D-xylopyranosylaucubin (5), ajugol (6), ajugoside (7), an iridoid-related aglycone (10) and angoroside C (11). Nine isolates were active against Leishmania donovani, with the new compound 9 being most potent (IC50 6.1 microg/ml). Except for 4, all pure compounds revealed some trypanocidal potential against Trypanosoma brucei rhodesiense (IC50 values 29.3-73.0 microg/ml). Only compound 10 showed moderate anti-plasmodial (IC50 40.6 microg/ml) and FabI enzyme inhibitory activity (IC50 100 microg/ml). 10 is the second natural product inhibiting the fatty acid biosynthesis of Plasmodium falciparum.     

Efficacy of karanjin and phorbol ester fraction against termites (Odontotermes obesus)

The non-edible oil seeds of Jatropha curcas (physic nut) and Pongamia pinnata (karanja) contain some toxic components (phorbol esters in J. curcas and karanjin in P. pinnata), which may be used as biopesticides. In this study, the active components of J. curcas and P. pinnata oil were extracted and their efficacy against the termites Odontotermes obesus (Rambur), was tested. The phorbol ester fraction of J. curcas and karanjin of P. pinnata oil were found to be effective against termites. A mortality rate of 100% was achieved in 6 h with karanjin and in 12 h with phorbol ester fraction. The LC₅₀ levels of karanjin and phorbol esters fractions were 0.038 and 0.071 g ml⁻¹, respectively, after 24 h at a 95% (0.05) confidence limit.     

Mulberry anthracnose antagonists (iturins) produced by Bacillus amyloliquefaciens RC-2

Bacillus amyloliquefaciens strain RC-2 produced seven antifungal compounds (1-7) secreted into the culture filtrate. These compounds inhibited the development of mulberry anthracnose caused by the fungus, Colletotrichum dematium. Chemical structural analyses by NMR and FAB-MS revealed that all these compounds were iturins (cyclic peptides with the following sequence: L-Asn --> D-Tyr --> D-Asn --> L-Gln --> L-Pro --> D-Asn --> L-Ser --> D-beta-amino acid -->) and compounds 1-6 are identical to iturins A-2-A-7, respectively. Compound 7 (iturin A-8) is a new iturin, which has a -(CH(2))(10)CH(CH(3))CH(2)CH(3) group as a side chain in the beta-amino acid in the molecule.     

Phenolics from the culms of five bamboo species in the Tangjiahe and Wolong Giant Panda Reserves,Sichuan, China

Phenolic compounds were studied in the culms of five bamboo species collected in China: Yushania chungii, Fargesia robusta, Fargesia denudata, Fargesia rufa and Fargesia scabrida. All the species are eaten by giant panda (Ailuropoda melanoleuca). The culms contained phenolic acids and flavonoids in small concentrations, except for F. robusta, which did not contain flavonoids in detectable amounts. The species differed from each other in their phenolic composition. For example, F. rufa with the highest number of compounds clearly differed from other species. There were also differences among sampling sites, which reflect the differences among genotypes. Furthermore, there were clear ontogenetic differences in the culms: some compounds were present in mature culms but not in young (1–2 year old) culms, while the concentrations of other compounds decreased with increasing age. Over all, the composition and concentrations of soluble phenolic compounds in the bamboo culms were affected by species, age and site.     

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).     

Antifungal amides from Piper arboreum and Piper tuberculatum

In continuation of our study of the Piperaceae we have isolated several amides, mainly those bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. Bioactivity-guided fractionation of extracts from leaves of Piper arboreum yielded two new amides, N-[10-(13,14-methylenedioxyphenyl)-7(E),9(Z)-pentadienoyl]-pyrrolidine (1), arboreumine (2) together with the known compounds N-[10-(13,14-methylenedioxyphenyl)-7(E)-pentaenoyl]-pyrrolidine (3) and N-[10-(13,14-methylenedioxyphenyl)-7(E),9(E)-pentadienoyl]-pyrrolidine (4). Catalytic hydrogenation of 3 yielded the amide N-[10-(13,14-methylenedioxyphenyl)-pentanoyl]-pyrrolidine (5). We also have isolated six amides (6-11) and two antifungal cinnamoyl derivatives (12, 13) from seeds and leaves of Piper tuberculatum. Compounds 1-11 showed antifungal activity as determined by direct bioautography against Cladosporium sphaerospermum while compounds 3-4 and 6-13 also showed antifungal activity against C. cladosporioides.     

Immunosuppressive pregnane glycosides from Periploca sepium and Periploca forrestii

Nine pregnane glycosides containing peroxy functions in their sugar moieties (1-5 and 11-14), five oligosaccharides (6-10), six pregnane glycosides (15-20), and five cardiac glycosides (21-25) were isolated from the root barks of Periploca sepium Bge. (Asclepiadaceae) and the roots of Periploca forrestii Schltr. (Asclepiadaceae), two traditional Chinese medicines used for the treatment of rheumatoid arthritis. Among them, 1-8 are hitherto unknown. Their structures were characterized on the basis of spectroscopic analyses. In pharmacological testing, compounds 1-5 and 11-14 were found to exhibit inhibitory activity against the proliferation of T lymphocyte in vitro with IC50 values ranging from 0.29microM to 1.97microM, while the other components showed no significant inhibitory activity.     

Antimicrobial constituents of Scrophularia deserti

A study of the chemistry and antibacterial activity of Scrophularia deserti led to the isolation of eight compounds, including the metabolite 3(zeta)-hydroxy-octadeca-4(E),6(Z)-dienoic acid (1). The known compounds ajugoside (2), scropolioside B (3), 6-O-alpha-L-rhamnopyranosylcatalpol (4), buddlejoside A(8) (5), scrospioside A (6), laterioside (7) and 3R-1-octan-3-yl-3-O-beta-D-glucopyranoside (8) were also isolated. Compounds 1-3 exhibited moderate antibacterial activity against strains of multidrug and methicillin-resistant Staphylococcus aureus (MRSA) and a panel of rapidly growing mycobacteria with minimum inhibitory concentration (MIC) values ranging from 32 to 128 microg/ml.     

Chemical constituents from the fruits of Sonneratia caseolaris and Sonneratia ovata (Sonneratiaceae)

Nine (1–9) and seven (1–6, 10) compounds were isolated from the fruits of Sonneratia caseolaris and Sonneratia ovata, respectively. Their structures were identified by comparing their MS and NMR data as well as the physical properties with the literature. All the isolated compounds were screened against a rat glioma C-6 cell line using the MTT assay method; only compounds (-)-(R)-nyasol (1), (-)-(R)-4′-O-methylnyasol (2) and maslinic acid (6) were found to show moderate cytotoxic activity. Our findings from these two kinds of fruits can be used as a foundation for further chemotaxonomic studies on Sonneratia species. The nor-lignans (1, 2) and 6H-benzo[b,d]pyran-6-one derivatives (3, 4) were isolated from this genus for the first time, indicating that these two classes of compounds may tentatively be considered as taxonomic markers for Sonneratia genus.     

Phytotoxic activity and conformational analysis of thymol analogs from Hofmeisteria schaffneri

Bioassay-guided fractionation of two phytotoxic extracts (a CH(2)Cl(2)-MeOH (1:1) and an aqueous) prepared from the aerial parts of Hofmeisteria schaffneri led to isolation of thymol analogs 3-5, along with seven known compounds, 1, 2 and 6-10. Compounds 3-5 were identified by spectroscopic methods as 1,4-bis(2'-hydroxy-4'-methylphenyl)butane-1,4-dione (3), 2-isopropyl-5-methylphenyl (2Z)-2-methylbut-2-enoate (4) and 2-hydroxy-2-(2-hydroxy-4-methylphenyl)propane-1,3-diyl (2Z,2'Z)bis(2-methylbut-2-enoate) (5) and designated trivial names of hofmeisterins II-IV, respectively. Their conformational behavior was also studied by molecular modeling using density functional theory calculations at the B3LYP/DGDZVP level. Compounds 1-4 and 6-10 significantly inhibited radicle growth of seedlings of Amaranthus hypochondriacus and Echinochloa crus-galli in the Petri dish bioassay with IC(50)'s10(-4)M. Furthermore, the northymol analog 3 provoked significant bleaching of seedlings of A. hypochondriacus. However, none of the isolates affected either seedling growth or germination of Medicago sativa.     

Isolation and structure elucidation of flavonoid and phenolic acid glycosides from pericarp of hot pepper fruit Capsicum annuum L

Hot pepper fruits (Capsicum annuum L.) var. Bronowicka Ostra have been studied with regard to content of flavonoids and other phenolics. Nine compounds were isolated from pericarp of pepper fruits by preparative HPLC. Their structures were identified by chromatographic (analytical HPLC) and spectroscopic (UV, NMR) techniques. Two of the identified compounds, trans-p-ferulylalcohol-4-O-(6-(2-methyl-3-hydroxypropionyl) glucopyranoside and luteolin-7-O-(2-apiofuranosyl-4-glucopyranosyl-6-malonyl)-glucopyranoside were found for the first time in the plant kingdom. Additionally compounds: trans-p-feruloyl-beta-D-glucopyranoside, trans-p-sinapoyl-beta- D-glucopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside-7-O-beta-D-glucopyranoside, luteolin 6-C-beta-D-glucopyranoside-8-C-alpha-L-arabinopyranoside, apigenin 6-C-beta-D-glucopyranoside-8-C-alpha-L-arabinopyranoside and luteolin 7-O-[2-(beta-D-apiofuranosyl)-beta-D-glucopyranoside] were found for the first time in pepper fruit Capsicum annuum L.