RESUMO
Three new labdane diterpenoids, pacovatinins A-C (1-3), were isolated from seeds of the Brazilian medicinal plant Renealmia exaltata ("Pacová-catinga"), and their structures including absolute configurations were elucidated by spectroscopic data and a modified Mosher method.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Diterpenos/isolamento & purificação , Plantas Medicinais/química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Brasil , Carcinoma de Células Escamosas , Diterpenos/química , Diterpenos/farmacologia , Humanos , Leucemia L1210 , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Conformação Molecular , Estrutura Molecular , Sementes/química , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Two new clerodane-type diterpenes, porwenins A (1) and B (2), were isolated from Portulaca okinawensis, and the structures were elucidated by spectroscopic data.
Assuntos
Diterpenos/química , Plantas Medicinais/química , Diterpenos/isolamento & purificação , Japão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria InfravermelhoRESUMO
Four new nitrogen-containing clerodane diterpenoids, echinophyllins C-F (1-4), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus ("Chapéu-de-couro"), and their structures and relative stereochemistry were elucidated from their spectroscopic data. Compounds 1-4 possess an alpha,beta-unsaturated gamma-lactam ring consisting of a clerodane diterpene unit and an amine moiety.
Assuntos
Diterpenos/química , Plantas Medicinais/química , Diterpenos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Folhas de Planta/química , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Some non-taxol-type taxoids having neither an oxetane ring at C-4 and C-5 nor an N-acylphenyl-isoserine group at C-13, such as taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J, which were isolated from the Japanese yew Taxus cuspidata, increased cellular accu-mulation of vincristine (VCR) in multidrug-resistant 2780AD cells as potently as verapamil, and efficiently inhibited [(3)H]azidopine photolabeling of P-glycoprotein (P-gp). Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J at 10 microM completely reversed the resistance to colchicine, VCR, and taxol in KB-C2 cells, which overexpress P-gp, while taxinine and taxinine M showed no effect. Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J may be candidate pharmaceuticals for reversing multidrug resistance (MDR) and also may be good modifiers of MDR in cancer chemotherapy.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Resistência a Múltiplos Medicamentos , Paclitaxel/análogos & derivados , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Colchicina/farmacologia , Interações Medicamentosas , Resistencia a Medicamentos Antineoplásicos , Humanos , Concentração Inibidora 50 , Células KB , Paclitaxel/farmacologia , Plantas Medicinais , Relação Estrutura-Atividade , Taxus , Células Tumorais Cultivadas , Vincristina/farmacocinética , Vincristina/farmacologiaRESUMO
A unique bicyclic peptide, moroidin (1), from the seeds of Celosia argentea (Amaranthaceae) strongly inhibited the polymerization of tubulin. The stereostructure of moroidin (1) was reinvestigated by spectroscopic data, chemical degradation, and molecular dynamics simulation.
Assuntos
Antineoplásicos/isolamento & purificação , Peptídeos Cíclicos/isolamento & purificação , Plantas Medicinais/química , Antineoplásicos/farmacologia , Colchicina/farmacologia , Dimetil Sulfóxido/química , Espectroscopia de Ressonância Magnética , Peptídeos Cíclicos/farmacologia , Sementes/química , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Ultravioleta , Tubulina (Proteína)/biossínteseRESUMO
A new seco-labdane-type diterpenoid, chapecoderin A (1), and two new rearranged labdane-type diterpenoids, chapecoderins B (2) and C (3), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus ("Chapéu-de-couro"), and their structures and relative stereochemistry were elucidated by spectroscopic data. Chapecoderins A-C (1-3) possess in common an alpha,beta-unsaturated gamma-lactone ring in the side chain.
Assuntos
Plantas Medicinais/química , Estrutura Molecular , Análise EspectralRESUMO
Leaf-movement in nyctinastic plants has long been believed to be controlled by plant hormones that are common among all nyctinastic plants. We have identified several bioactive substances for nyctinasty, whose bioactivities were highly specific to the original plant, based on the bioassay using the original plant leaf, and have shown that nyctinastic leaf-movement is not regulated by plant hormones. Our present results are in accordance with Umrath et al. physiologically significant opinion.