RESUMO
Breast cancer is the most common malignant tumor in women these days accounting for approximately 24% of all cancer. During our screening program searching for cytotoxic materials from natural products, two new symmetric dimers of ent-kaurane diterpenoid, crotonkinensins C (1) and D (2), with connectivity at C-17 were isolated from the leaves of the Vietnamese endemic medicinal plant Croton tonkinensis. Their structures were determined on the basis of physicochemical and spectroscopic data. Compound 2 showed a potent cytotoxic activity against MCF-7, tamoxifen-resistant MCF-7 (MCF-7/TAMR), adriamycin-resistant MCF-7 (MCF-7/ADR), and MDA-MB-231 breast cancer cell lines.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Croton/química , Diterpenos do Tipo Caurano/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dimerização , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/isolamento & purificação , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Two new diterpenoids, crotonkinensins A (1) and B (2), were isolated from the leaves of the Vietnamese endemic medicinal plant Croton tonkinensis. Their structures were determined to be 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(5),16(17)-dien-2,15-dione (1) and 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(2),16(17)-dien-15-one (2) by spectroscopic analysis. Compounds 1 and 2 showed strong anti-inflammatory effects on the LPS-induced COX-2 promoter activity and COX-2 expression in Raw 264.7 cells.