RESUMO
Falcatane A (1) and B (2), 4-oxo-3,24-dinor-2,4-secooleanane- and 3-oxo-24- noroleanane-type triterpenoids, together with seven known triterpenoids involving 2-hydroxy-3-oxo-24-noroleana-1,4,12-trien-28-oic acid (3) and oleanolic acid (4), were separated from the ethyl acetate roots extract of Dolichos trilobus using the column chromatography of silica gel, MCI gel, and Sephadex LH-20. The compounds were determined by analysis of IR, NMR spectroscopic data and mass spectrometry. In the bioassay, all isolates showed varying degree of the α-glucosidase inhibitory activity except compound 2.
Assuntos
Dolichos/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Dolichos/efeitos dos fármacos , Inibidores de Glicosídeo Hidrolases/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Raízes de Plantas/química , Espectrofotometria Infravermelho , Triterpenos/químicaRESUMO
An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH) carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%-99%) with good to high selectivity (Z/E from 79:21 to >99:1). Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.
Assuntos
Compostos Alílicos/química , Compostos Alílicos/síntese química , Carbonatos/química , Sulfonas/química , Sulfonas/síntese química , Catálise , TemperaturaRESUMO
Anti-selective Mannich reactions of N-Boc and N-Cbz protected imines with unmodified aldehydes proceeded smoothly under the catalysis of a secondary amine-thiourea catalyst, which led to high yields (70%-95%) and excellent enantioselectivity (up to 96 : 4 dr and >99% ee) under conventional organic synthetic operations.
