RESUMEN
A remarkable base-promoted methodology for the rapid construction of the (E)- and (Z)-γ-oxo-α,ß-alkenoic ester skeletons from readily accessible vinyl propargylic alcohols through modified redox isomerization was uncovered. This approach manifested its high simplicity and efficiency with excellent tolerance of functional substituents, which led to the straightforward structural modifications of various natural products and efficient total syntheses of melodienone, homomelodienone, isomelodienone, and homoisomelodienone within 4 linear steps.
RESUMEN
One new pentacyclic triterpenoid, urs-12,16-dien-3-one (1), together with twelve known pentacyclic triterpenoids (2â13), were isolated from the twigs and leaves of Melaleuca linariifolia. Their structures were characterized by their 1D- and 2 D-NMR spectra analysis and mass spectra studies. Furthermore, all isolated compounds were tested the inhibitory effect on proliferation of six human cancer cell lines in vitro, including NCI-H441, NCI-H460, A549, SKOV3, hela, and caki-1 cells. Among them, compounds 3, 5, 7, 9, 12, and 13 exhibited moderate antiproliferative activities with IC50 values ranging from 3.85 to 33.31 µM.
Asunto(s)
Melaleuca , Triterpenos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Hojas de la Planta , Triterpenos/farmacologíaRESUMEN
A highly substituted phenol derivative, effphenol A (1), was isolated from the deep-sea-derived fungus Trichobotrys effuse FS524. Its complete structural assignment was established through a combination of spectroscopic analysis together with single-crystal X-ray diffraction experiments and further unequivocally confirmed by a biomimetic total synthesis. Structurally, effphenol A possesses a poly-substituted 6-5/6/6 tetracyclic ring system, which represents the first case of such a skeleton found in nature. Furthermore, the cytotoxic activity of effphenol A (1) toward four human cancer cell lines was assayed.
Asunto(s)
AscomicetosRESUMEN
The first biomimetic total syntheses of natural phloroglucinols tomentosones A and B and their analogues have been accomplished. The synthetic strategy primarily referred to the potential biosynthetic precursors and their possible sequence of segments assembly by chemological evolution of the structural entities and enabled rapid access of the titled compounds in a practical fashion.
Asunto(s)
Antimaláricos/síntesis química , Floroglucinol/síntesis química , Antimaláricos/química , Biomimética , Estructura Molecular , Floroglucinol/química , EstereoisomerismoRESUMEN
Two new abietane diterpenoids, (3S,5R,10S)-3-hydroxy-12-O-demethyl-11-deoxy-19(4â3)-abeo-cryptojaponol, 12,19-dihydroxyabieta-8,11,13-trien-7-one, were isolated from Selaginella moellendorffii Hieron., together with one known abietane diterpenoid and four known tetracyclic triterpenoids. Their structures were characterized by their 1D- and 2D-NMR, ECD and mass spectral studies. All compounds were tested for their inhibitory effects on proliferation of three human cancer cells (human non-small-cell lung carcinoma cell lines A549 and human breast adenocarcinoma cell lines MDA-MB-231 and MCF-7) inâ vitro. Among them, three compounds displayed modest cytotoxic activities against the above three human cancer cell lines with IC50 values ranging from 16.28 to 40.67â µM.
Asunto(s)
Abietanos/química , Antineoplásicos Fitogénicos/química , Selaginellaceae/química , Abietanos/aislamiento & purificación , Abietanos/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Dicroismo Circular , Diterpenos/química , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Selaginellaceae/metabolismo , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
The first concise total syntheses of sanctis A and B were reported, and it enabled revision of the structure of sanctis B through single-crystal X-ray diffraction. The established synthetic approach mainly mimics a biosynthetic olefin isomerization/hemiacetalization/dehydration/[3 + 3]-type cycloaddition cascade sequence, offering a viable synthetic methodology to efficiently access sanctis A-B and their analogues.