RESUMEN
Propolis is a resinous substance collected by honeybees from certain plant sources. The components of propolis depend on the vegetation of the area in which apiculture is practiced. In Brazil, there are several types of propolis including 'green,' 'red' and 'brown'. Brazilian brown propolis from the state of Parana characteristically includes diterpenes, and we discovered a novel clerodane diterpene, rel-(5S,6S,8R,9R,10S,18R,19S)-18,19-epoxy-2-oxocleroda-3,12(E),14- triene-6,18,19-triol 18,19-diacetate 6-benzoate (3) and five known diterpenes (1, 2, 4, 5 and 6). The chemical structure of the novel diterpene 3 was determined using 1D- and 2D-NMR spectroscopic analyses. Furthermore, the activities of the isolated diterpenes on growth inhibition of several human cancer cell lines (LNCaP, MCF-7, DLD-1 and A549) were evaluated in vitro; diterpene 3 exhibited a potent inhibition of cell growth, and its activity was approximately 15 times higher than that of the other diterpenes.
Asunto(s)
Diterpenos de Tipo Clerodano/química , Própolis/química , Antineoplásicos/química , Antineoplásicos/farmacología , Brasil , Línea Celular Tumoral , Humanos , Estructura MolecularRESUMEN
Fourteen cassane-type diterpenoids, echinalides H-U, were isolated from the stem of Caesalpinia echinata Lam. (Leguminosae). The structures of the echinalides were elucidated by spectroscopic investigation, including 2D NMR spectroscopic analysis. The structures of echinalide H and echinalide T were further confirmed by single-crystal X-ray diffraction. The absolute configurations of echinalides H, I, J and K were determined by CD spectroscopy. Additionally, the absolute configurations of echinalide L and M were determined by chemical conversion from echinalide H. These compounds were evaluated for inhibitory activity against nuclear factor κB (NF-κB). Echinalide M showed the most potent inhibitory activity (47±11% at 5µM) toward NF-κB-responsive gene expression.
Asunto(s)
Caesalpinia/química , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , FN-kappa B/antagonistas & inhibidores , Brasil , Cristalografía por Rayos X , Diterpenos/química , Células HeLa , Humanos , Proteínas I-kappa B , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Tallos de la Planta/química , Semillas/química , Transducción de Señal/efectos de los fármacosRESUMEN
Two new clerodane diterpenoids, gaudichanolides A (1) and B (2), were isolated from the dried twigs of Baccharis gaudichaudiana, together with 7-oxo-16,19-dihydroxy-3,4-dehydroclerodan-15,20-diacid dilactone, spathulenol, 4,10-aromadendranediol, kobusone, trans-cosanyl ferulate, and defuscin. The structures and relative stereochemistry of 1 and 2 were elucidated by detailed 2D NMR spectroscopic experiments, and the absolute stereochemistry of 1 was determined by X-ray crystallographic analysis.
Asunto(s)
Baccharis/química , Diterpenos de Tipo Clerodano/aislamiento & purificación , Plantas Medicinales/química , Brasil , Cristalografía por Rayos X , Diterpenos de Tipo Clerodano/química , Conformación Molecular , Estructura MolecularRESUMEN
In a continuing study to isolate novel antitumor agents from rainforest plants, three new isopropenylfurano-beta-naphthoquinones, designated lantalucratins A (1), B (2), and C (3), and three new isoprenyl-alpha-naphthoquinones, designated lantalucratins D (4), E (5), and F (6), were isolated from Lantana involucrata. Their structures were determined on the basis of NMR and X-ray crystallographic analyses. Compounds 1 and 2 showed cytotoxic activities against various human tumor cell lines, including drug-resistant variants, with IC50 values of 1.0-4.9 microM.
Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Lantana/química , Naftoquinonas/aislamiento & purificación , Plantas Medicinales/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Resistencia a Antineoplásicos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Naftoquinonas/química , Naftoquinonas/farmacología , Resonancia Magnética Nuclear Biomolecular , Puerto Rico , Células Tumorales CultivadasRESUMEN
As part of a study on antitumor agents from rainforest plants, two new flavanones, buceracidin A (1), 5,2'-dihydroxy-3-methoxy-6,7-(2' ',2' '-dimethylchromene)flavanone, and buceracidin B (2), 5,2'-dihydroxy-6,7-(2' ',2' '-dimethylchromene)flavanone, were isolated together with four known prenylated flavanones, minimiflorin (3), 3-hydroxyminimiflorin (4), 3-methoxyminimiflorin (5), and mundulinol (6), from Bucida buceras. The structures of buceracidins A and B were elucidated from detailed 2D NMR analyses. Among the six flavanones, 3, 5, and 6 were marginally cytotoxic in a human tumor cell line panel.