RESUMO
Chemical investigation of the culture extract of an endophytic Penicillium citrinum from Dendrobium officinale, afforded nine citrinin derivatives (1-9) and one peptide-polyketide hybrid GKK1032B (10). The structures of these compounds were determined by spectroscopic methods. The absolute configurations of 1 and 2 were determined for the first time by calculation of electronic circular dichroism (ECD) data. Among them, GKK1032B (10) showed significant cytotoxicity against human osteosarcoma cell line MG63 with an IC50 value of 3.49 µmol·L-1, and a primary mechanistic study revealed that it induced the apoptosis of MG63 cellsvia caspase pathway activation.
Assuntos
Neoplasias Ósseas , Osteossarcoma , Apoptose , Caspases , Humanos , Osteossarcoma/tratamento farmacológico , PenicilliumRESUMO
Eleven new highly oxygenated germacrane-type sesquiterpenoids (1-11) and 16 known analogues (12-27) were isolated from the aerial parts of Sigesbeckia orientalis. Their structures, including absolute configurations, were determined by comprehensive spectroscopic methods especially NMR and ECD analyses. Compounds 13, 21 and 23 possessing an 8-methacryloxy group showed stronger in vitro cytotoxicity against human A549 and MDA-MB-231 cancer cell lines than other co-metabolites, with IC50 values ranging from 6.02 to 10.77⯵M comparable to the positive control adriamycin.
Assuntos
Antineoplásicos Fitogênicos/química , Asteraceae/química , Extratos Vegetais/química , Sesquiterpenos de Germacrano/química , Sesquiterpenos/química , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Relação Estrutura-AtividadeRESUMO
Two polyketides, stemonones A (1) and B (2) with new skeletons, were isolated from the roots of Stemona tuberosa. Their absolute structures were fully characterized by comprehensive spectroscopic analyses and comparison of experimental electronic circular dichroism (ECD) spectra with calculated ones. The plausible biosynthetic pathways for 1 and 2 were also proposed. Anti-inflammatory assay confirmed that the two compounds showed moderate inhibitory effects on ß-glucuronidase release in rat polymorphonuclear leukocytes (PMNs) induced by platelet-activating factor.
Assuntos
Anti-Inflamatórios/química , Policetídeos/química , Stemonaceae/química , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Células Cultivadas , China , Glucuronidase/metabolismo , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Raízes de Plantas/química , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , RatosRESUMO
Two new alkaloids, flueggether A (1) and virosinine A (2), were isolated from a Chinese medicinal plant, Flueggea virosa. Their structures were assigned via spectroscopic methods with the absolute configurations of 1 and 2 being established by X-ray diffraction analysis and calculated electronic circular dichroism data, respectively. Compound 1 represents the first example with an ether bridge of Securinega alkaloid oligomers, and 2 bears a new heterocyclic backbone. Both alkaloids showed mild in vitro anti-HIV activity.
Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Fármacos Anti-HIV/isolamento & purificação , Fármacos Anti-HIV/farmacologia , Euphorbiaceae/química , Alcaloides/química , Fármacos Anti-HIV/química , Cristalografia por Raios X , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Plantas Medicinais/químicaRESUMO
Five new ent-pimarane (1-3, 7, and 8) and three new ent-kaurane diterpenoids (4-6) and a new oleanane triterpene acid (9), together with 22 known compounds, were isolated from the root bark of the medicinal herb Acanthopanax gracilistylus. The structures of 1-9 were established based on the interpretation of high-resolution MS and 1D- and 2D-NMR data. The absolute configurations of 7 and 11 were determined by single-crystal X-ray diffraction and electronic circular dichroism analysis. Compounds 7 and 8 represent rare naturally occurring structures based on the devinyl ent-pimarane skeleton. Compounds 3, 10, 14, 16, and 17 exhibited potent inhibitory effects on the release of interleukin-1ß (IL-1ß), interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) in lipopolysaccharide-stimulated peripheral blood mononuclear cells.
Assuntos
Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Diterpenos do Tipo Caurano/isolamento & purificação , Diterpenos do Tipo Caurano/farmacologia , Eleutherococcus/química , Plantas Medicinais/química , Anti-Inflamatórios/química , Cristalografia por Raios X , Diterpenos do Tipo Caurano/química , Interleucina-1beta/efeitos dos fármacos , Interleucina-8/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Lipopolissacarídeos/sangue , Lipopolissacarídeos/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Fator de Necrose Tumoral alfa/efeitos dos fármacosRESUMO
Biogenesis inspired chemical investigation of a Chinese folk medicine, Flueggea virosa, returned three unprecedented C,C-linked trimeric Securinega alkaloids, fluevirosines A-C (1-3). Their absolute structures were characterized on the basis of spectroscopic data and computational analysis. Compounds 2 and 3 showed inhibition against the splicing of XBP1 mRNA.