RESUMO
A phytochemical investigation of the foliose lichen Parmotrema tsavoense (Krog and Swinscow) Krog and Swinscow (Parmeliaceae) resulted in the isolation of a new trichlorinated xanthone, isodemethylchodatin. The structure elucidation of this new norlichexanthone derivative proved tricky owing to proton deficiency, and to the lack of NMR data of closely related analogues. The structure of this compound was determined based on an integrated interpretation of 13C-NMR chemical shifts, MS spectra, and DP4-based computational chemistry was also performed to provide an independent and unambiguous validation of the determined structure. Isodemethylchodatin represents the first chlorinated lichexanthone/norlichexanthone derivative bearing a methoxy group at C-5.
Assuntos
Hidrogênio/química , Líquens/química , Xantonas/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Espectroscopia de Prótons por Ressonância Magnética , EstereoisomerismoRESUMO
New racemic dispiranic polyketides, tsavoenones A (1), B (2) and C (3), having a novel 1,7-dioxadispiro[4.0.4.4]tetradecane scaffold were isolated from the foliose lichen Parmotrema tsavoense. These compounds were structurally elucidated by extensive NMR analyses, comparison between experimental and theoretical 13C NMR data and X-ray crystallography. A putative biosynthetic scenario for the formation of 1-3 from parmosidone D, a meta-depsidone previously isolated from the same lichen material, was proposed. Tested for its cytotoxicity, 1 displayed a moderate activity against human myelogenous leukemia K562 cell line with an IC50 value of 66 µg mL-1.
RESUMO
Six new sulfonic acid-containing flavonoids, acidoflavanone (1), acidoauronol (2), 5- O-methylacidoauronol (3), acidoaurone (4), acidoisoflavone (5), and acidoflavonol (6), were isolated from the EtOH extract of the roots of Phyllanthus acidus. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data, single-crystal X-ray diffraction analysis, and comparison to the literature data. These new structures represent the first examples of sulfonic acid-containing flavanones, auronols, aurones, and isoflavones.
Assuntos
Flavonoides/isolamento & purificação , Phyllanthus/química , Flavonoides/análise , Flavonoides/química , Flavonoides/farmacologia , Espectroscopia de Ressonância Magnética , Extratos Vegetais/análise , Raízes de Plantas/química , Ácidos Sulfônicos/análise , Difração de Raios XRESUMO
Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-ß-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata. Their chemical structures were established by spectroscopic data, as well as high resolution mass spectra and comparison with literature data. The in vitro acetylcholinesterase (AChE) inhibition and cytotoxic activities against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), MCF-7 (human breast cancer) cancer cell lines and PHF (primary human fibroblast) cell were evaluated on some extracts and purified compounds at a concentration of 100 µg/mL. Compounds (5, 6, 23) exhibited cytotoxicity against the MCF-7 cell line with the IC50 values of 146.9±9.0, 114.5±7.2, and 112.8±9.4 µM, respectively, while they showed nontoxic with the normal cell (PHF) with IC50s >277 µM. Among 15 tested compounds, (S)-rhodolatouchol (22) showed inhibition against AChE with an IC50 value of 96.1±14.5 µM.
Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Plantas/química , Acetilcolinesterase/metabolismo , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética , Modelos MolecularesRESUMO
Whereas standard strong bases (n-BuLi, s-BuLi/TMEDA, n-BuLi/t-BuOK, TMPMgCl·LiCl, and LDA) reduce the NâN bond of the parent azobenzene (Y = H), aromatic HâLi permutation occurs with LTMP when a suitable director of lithiation (Y = OMe, CONEt2, F) is present in the benzene residue of the azo compound. The method allows direct access to new substituted azobenzenes.
RESUMO
Three series of methyl 5-substituted 2-aminofuran-4-keto-3-carboxylates have been prepared following a multicomponent reaction strategy by the addition of an isocyanide to 4-oxo-2-butynoate in the presence of an aldehyde. The cycloaddition regioselectivity is generally high (>95%) but decreases when an electron-rich substituent is located at the butynoate 4-position.
Assuntos
Ácidos Carboxílicos/síntese química , Cianetos/química , Ácidos Graxos Monoinsaturados/química , Furanos/síntese química , Aldeídos/química , Reação de Cicloadição , EstereoisomerismoRESUMO
A new cucurbitacin, 3ß-(ß-D-glucopyranosyloxy)-5ß,6ß:16α,23α-diepoxycucurbit-24-en-11-one or hygrocucurbin A (1), along with two known compounds, including 3ß-(ß-D-glucopyranosyloxy)-16α,23α-epoxycucurbita-5,24-dien-11-one (2) and (+)-lyoniresinol (3), were isolated from the bark of Elaeocarpus hygrophilus. Their chemical structures were elucidated by spectroscopic NMR, HR-IDA- TOF-MS analysis, and by comparison with the spectral data of corresponding compounds in the literature. Two cucurbitacins (1) and (2) were evaluated for their α-glucosidase inhibitory activity and cytotoxic against KB, MCF-7, Hep G2, and A549 cancer cell lines. For the α-glucosidase inhibitory activity, compound 1 showed an equivalent effect (IC50 197.4 ± 4.1 µM) compared to the acarbose, a positive control (IC50 208.5 ± 4.7 µM). And for the cytotoxicity, 2 was inactive while 1 was slightly sensitive against KB cells (IC50 233.3 ± 2.5 µM).
RESUMO
Two new triterpenoid saponins, named spermacosides A-B (1 - 2), together with two known oleanane-type triterpenoid saponins, 3-O-ß-D-xylopyranosyl-(1â3)-ß-D-glucopyranosylbayogenin (3) and 3-O-ß-D-glucopyranosylbayogenin (4), were isolated from the ethyl acetate extract of Spermacoce ocymoides Burm.f. in a phytochemical investigation. Their chemical structures were elucidated by spectroscopic data analysis (1D and 2D NMR, and HR-ESI-MS), as well as comparison with reported data. All these compounds were evaluated for inhibiting nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. Among them, 1 showed a slight effect with an IC50 value of 108.65 ± 7.91 µM, and compounds 2-4 were inactive.
RESUMO
The phytochemical composition of the Combretum trifoliatum leaves was studied for the first time. Two new triterpenoid saponins, named comtrifoside A (1) and comtrifoside B (2), together with two other saponins (3-4) were purified by variously chromatographic techniques. For the first time, compound 3 was informed from the Combretum genus, as well as all of the isolated compounds (1-4) were reported from C. trifoliatum. The chemical structures of them were clearly characterised using extensive UV-VIS, IR, HRMS-ESI, and NMR experimental data. The in vitro anti-inflammatory activities of 1 & 2 were examined against NO overproduction in LPS activation of RAW264.7.
RESUMO
Tithonia tagetiflora Desv. (Asteraceae) is a widespread plant in Vietnam, and the species of Tithonia are known as plants containing many biologically active compounds. However, T. tagetiflora's chemical composition remains mostly unknown. Therefore, we now report the structural elucidation of two new sesquiterpene lactones, 8-angeloyloxy-2,14-epoxygermacra-4,10(1),11(13)-trien-6,12-olide (1) and 6-angeloyloxy-1-hydroxy-3,4-epoxygermacra-9,11(13)-dien-8,12-olide (2), together with three known compounds, including two norisoprenoids, (6S,9S)-vomifoliol or (6R,9R)-vomifoliol (3) and (6S,9S)-roseoside (4), and one glutinane type triterpene, epi-glutinol (5), from the leaves of T. tagetiflora. Their structures are established by 1D and 2D NMR spectroscopy, as well as ESI-MS analysis and comparison with literature data.
Assuntos
Asteraceae/química , Butanóis/química , Cicloexanonas/química , Glucosídeos/química , Lactonas/química , Norisoprenoides/química , Folhas de Planta/química , Sesquiterpenos/química , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , VietnãRESUMO
From the aerial part of Boerhaavia erecta L., three new rotenoids (3, 8, 10) and two new coumaronochromonoids (6, 11) were isolated, together with ten known compounds. The structure of the new compounds was established by one dimensional (1D)- and 2D-NMR spectroscopy, as well as high resolution-electrospray ionization (HR-ESI)-MS analysis. The absolute configuration of compound 11 was determined by UV circular dichroism spectroscopy. Compounds were evaluated for their cytotoxic activity against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer) and MCF-7 (human breast cancer) cell lines at the concentration of 100 µg/mL. Rotenoids 3, 4 and 5 showed a strong cytotoxic activity against HeLa cell line and rotenoids 5 and 8 showed good activity against MCF-7 cell line.
Assuntos
Antineoplásicos Fitogênicos/química , Flavonoides/química , Nyctaginaceae/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/toxicidade , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Flavonoides/isolamento & purificação , Flavonoides/toxicidade , Células HeLa , Humanos , Células MCF-7 , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Componentes Aéreos da Planta/químicaRESUMO
Two new oleanane saponins, hedyocoronin A (1) and hedyocoronin B (2), were isolated from the aerial parts of Hedyotis coronaria (Kurz) Craib, Rubiaceae, collected at Da Oai district, Lam Dong province in Vietnam. Their chemical structures were elucidated by HR-MS, 1D and 2D-NMR spectra, along with the comparison with those reported in the literature. Compounds 1 and 2 showed weak cytotoxicity against KB and HeLa-S3 cancer cell lines with IC50 values of more than 54 µM.
Assuntos
Antineoplásicos Fitogênicos , Hedyotis , Ácido Oleanólico , Rubiaceae , Saponinas , Triterpenos , Saponinas/química , Hedyotis/química , Estrutura Molecular , Ácido Oleanólico/química , Componentes Aéreos da Planta/química , Antineoplásicos Fitogênicos/química , Triterpenos/químicaRESUMO
Two new sesquiterpene lactones, laurenolide A (1) and laurenolide B (2), along with six known compounds, palmitic acid (3), (R,R)-hexahydrofarnesyl acetone (4), trans-phytol acetate (5), cholesterol (6), cholesteryl acetate (7), cholesteryl heptadecanoate (8) were isolated from Palisada intermedia. The chemical structures of all compounds were elucidated by 1D and 2D-NMR spectroscopy and HR-ESI-MS analysis as well as compared with data in the literature. The petroleum ether, chloroform, ethyl acetate, methanol extracts and compounds 1, 2 were tested for the inhibition of two cancer cell lines MCF-7, NCI-H460 and they showed weak or none activities.
RESUMO
A new pregnane steroid, jasminanthoside (1), together with three known compounds, telosmoside A7 (2), syringaresinol (3), and methyl 6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1â4)-ß-D-oleandropyranoside (4) were isolated from the ethyl acetate extract of Jasminanthes tuyetanhiae roots collected in Vietnam. Their chemical structures were elucidated by NMR and MS spectroscopic data analysis along with the comparison of their data with the published ones in the literature. Although 4 was a known compound, its full NMR data were reported for the first time. All isolated compounds, evaluated for their α-glucosidase inhibition, showed activities stronger than the positive control acarbose. Among them, 1 was the best with the IC50 value of 7.41 ± 0.59 µM.
RESUMO
A new glutinane-triterpenoid, nepetifoliol (1), together with two known compounds, dymacrin D (2), and (+)-ar-tumerone (3) were isolated from the n-hexane extract of the aerial parts of Leonotis nepetifolia. Their chemical structures were elucidated by spectroscopic data analysis as well as the comparison of their NMR data with the ones published in the literatures. A putative biosynthetic pathway for the formation of the new compound (anti-diaxial-5,6-diol) (1) from the precursor triterpene glutinol was proposed. Compounds (2), (3) and some previously reported ones, isolated from this extract, including 5α-stigmasta-22-ene-3-one (4), friedelin (5), chrysophanol (6), physcion (7), and 4'-O-methylalpinumisoflavone (8) were evaluated for their α-glucosidase inhibition. Among tested compounds, 3 and 6 showed good activities with their IC50 values of 5.3 ± 0.2 and 4.9 ± 0.3 µg/mL, respectively, comparing to the positive control, acarbose (IC50 127.7 ± 0.2 µg/mL).
Assuntos
Lamiaceae , Triterpenos , alfa-Glucosidases/metabolismo , Espectroscopia de Ressonância Magnética , Triterpenos/farmacologia , Triterpenos/química , Lamiaceae/química , AcarboseRESUMO
Two new lignans, pseuderesinol (1), pseuderanoside (2) and a new triterpene, pseuderanic acid (3) were isolated from the dried root of Pseuderanthemum carruthersii (SEEM.) GUILL. var. atropurpureum (BULL.) FOSB. (Acanthaceae), together with ten known compounds, including five lignans, (+)-eudesmin (4), (+)-magnolin (5), (+)-syringaresinol (6), (+)-episyringaresinol (7), (+)-1-hydroxysyringaresinol (8) and five triterpenes, squalene (9), oleanolic acid (10), lupeol (11), betulin (12), betulinic acid (13). Their chemical structures were elucidated by 1D- and 2D-NMR, computational quantum chemistry, as well as high resolution-electrospray ionization (HR-ESI)-MS spectroscopic analysis. The acetylcholinesterase inhibition and cytotoxic activities against HeLa and MCF-7 cancer cell lines were evaluated on some purified compounds at the concentration of 100 µg/mL. Pseuderesinol (1) and magnolin (5) exhibited moderate cytotoxic activities against the MCF-7 cancer cell line.
Assuntos
Acanthaceae/química , Antineoplásicos Fitogênicos/farmacologia , Lignanas/farmacologia , Raízes de Plantas/química , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Lignanas/química , Lignanas/isolamento & purificação , Neoplasias/tratamento farmacológico , Triterpenos/química , Triterpenos/isolamento & purificaçãoRESUMO
Chemical investigation of the lichen Usnea ceratina Arch led to the isolation of five depsidones, including one new compound ceratinalone (1) along with four known compounds bailesidone (2), stictic acid (3), 8'-O-methylstictic acid (4) and 8'-O-ethylstictic acid (5). The structures were determined by analysis of their MS and NMR data as well as by comparison with literature values. Compounds 1 and 4 were evaluated the cytotoxic activity against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), HepG2 (liver hepatocellular carcinoma), and MCF-7 (human breast cancer) cell lines, showing the moderate activity.
Assuntos
Líquens , Parmeliaceae , Usnea , Animais , Ascomicetos , Depsídeos/química , Depsídeos/farmacologia , Humanos , Lactonas , Usnea/químicaRESUMO
Three new diphenyl ethers, named praesorethers E, F and G (1, 2 and 3), were isolated from the lichen Parmotrema praesorediosum. Their chemical structures were elucidated on the basis of extensively spectroscopic analysis including HR-ESI-MS and NMR as well as comparison with previously published data. These compounds were evaluated for the cytotoxicity against three human cancer cell lines (HeLa, NCI-H460 and MCF-7) using SRB assay. As results, 1 and 2 exhibited weak cytotoxic activity against three tested cancer cell lines with the inhibitive percentage of 64-79.9% at the concentration of 100 µg/mL while 3 was inactive.
Assuntos
Líquens , Parmeliaceae , Humanos , Líquens/química , Estrutura Molecular , Parmeliaceae/química , Éteres FenílicosRESUMO
Chemical investigation of the Vietnamese plant Aegiceras floridum Roem. & Schult. (Primulaceae) led to the isolation of the new compound 3-methoxy-5-nonylphenol (1) along with five known ones 2,8,10-trihydroxy-6H-benzo[c]chromen-6-one (2), 2-hydroxy-5-methoxy-3-nonylbenzo-1,4-quinone (3), 5-(3-hydroxypropyl)-7-methoxy-3-(methylbenzofuran-2-yl)-3-methoxyphenol (4), 2,8-dihydroxy-7-methoxy-3,9-diundecyldibenzofuran-1,4-dione (5) and 10-hydroxy-4-methoxy-2,11-diundecylgomphilactone (6). The structures were elucidated by analysis of their HRESIMS and NMR data as well as the comparison of their NMR data with those reported in the literature. The cytotoxic activity of selected isolated compounds against some cancer cell lines such as human epithelial carcinoma (HeLa), human lung cancer (NCI-H460), liver hepatocellular carcinoma (HepG2), human breast cancer (MCF-7), and acute T cell leukemia (Jurkat) was evaluated. Among them, 3 showed moderate activities against MCF-7 with an IC50 of 17.77 µM and NCI-H460 with an IC50 of 25.02 µM. The result of DPPH radical scavenging activity assay indicated that compounds 2-4 and 6 revealed weak antioxidant activity.
Assuntos
Primulaceae , Antioxidantes/análise , Antioxidantes/farmacologia , Células HeLa , Humanos , Casca de Planta/química , Primulaceae/química , Resorcinóis/análise , Resorcinóis/farmacologiaRESUMO
Three new phenolic compounds, peruvinides A-C were isolated from the lichen Ramalina peruviana Ach. (Ramalinaceae). Their structures were unambiguously determined by extensive spectroscopic analyses and comparison with literature data. Peruvinides A and B bearing unusual moieties were found for the first time among lichen metabolites.