RESUMEN
Assay-guided fractionation of the ethanol extract of the twigs and leaves of Miconia myriantha yielded two new compounds, mattucinol-7-O-[4' ',6' '-O-(S)-hexahydroxydiphenoyl]-beta-D-glucopyranoside (1) and mattucinol-7-O-[4' ',6' '-di-O-galloyl]-beta-D-glucopyranoside (2), along with mattucinol-7-O-beta-D-glucopyranoside (3), ellagic acid (4), 3,3'-di-O-methyl ellagic acid-4-O-beta-D-xylopyranoside, and gallic acid. Complete (1)H and (13)C NMR assignments of compound 1, which possesses a hexahydroxydiphenoyl unit, were achieved using the HMBC technique optimized for small couplings to enhance the four-bond and two-bond H/C correlations. Compounds 1 and 4 showed inhibitory effects against Candida albicans secreted aspartic proteases, with IC(50) of 8.4 and 10.5 microM, respectively.
Asunto(s)
Glucósidos/aislamiento & purificación , Magnoliopsida/química , Plantas Medicinales/química , Inhibidores de Proteasas/aislamiento & purificación , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Candida albicans/efectos de los fármacos , Candida albicans/enzimología , Candida albicans/metabolismo , Cromatografía en Capa Delgada , Dicroismo Circular , Ácido Elágico/química , Ácido Elágico/farmacología , Ácido Gálico/química , Ácido Gálico/farmacología , Glucósidos/química , Glucósidos/farmacología , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Conformación Molecular , Estructura Molecular , Pepsina A/antagonistas & inhibidores , Perú , Hojas de la Planta/química , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Espectrofotometría Infrarroja , Espectroscopía Infrarroja por Transformada de Fourier , Relación Estructura-ActividadRESUMEN
A novel naphthopyrone derivative, named quinquangulone (1), has been isolated from Cassia quinquangulata, along with the known compounds quinquangulin (2) and its two glycosides (3 and 4), rubrofusarin (5) and its two glycosides (6 and 7), nor-rubrofusarin (8) and its 6-O-glucoside (9), and three stilbenes (10-12). The structure of quinquangulone was established by spectral interpretation as 5,9-dihydroxy-8-methoxy-2,9-dimethyl-6-oxo-4H,6H,9H-naphtho-[2,3-b]pyran-4-one. Reinvestigation of the NMR spectra of quinquangulin led to revision of its structure as 5,6-dihydroxy-8-methoxy-2,9-dimethyl-4H-naphtho[2,3-b]pyran-4-one (2a). The structures of two quinguangulin glycosides, 3 and 4, were also revised accordingly. Compound 2a exhibited activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC, 3.125 and 6.25 microg/mL, respectively).
Asunto(s)
Antiinfecciosos/aislamiento & purificación , Cassia/química , Glucósidos/aislamiento & purificación , Glicósidos/aislamiento & purificación , Naftoles/aislamiento & purificación , Pironas/aislamiento & purificación , Antibacterianos , Antiinfecciosos/química , Antiinfecciosos/farmacología , Aspergillus fumigatus/efectos de los fármacos , Candida albicans/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Cryptococcus neoformans/efectos de los fármacos , Farmacorresistencia Microbiana , Glucósidos/química , Glucósidos/farmacología , Glicósidos/química , Glicósidos/farmacología , Espectroscopía de Resonancia Magnética , Resistencia a la Meticilina , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Estructura Molecular , Complejo Mycobacterium avium/efectos de los fármacos , Naftoles/química , Naftoles/farmacología , Perú , Raíces de Plantas/química , Plantas , Plantas Medicinales/química , Pironas/química , Pironas/farmacología , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Staphylococcus aureus/efectos de los fármacosRESUMEN
Bioassay-guided isolation of Duguetia hadrantha yielded two new 4,5-dioxo-1-azaaporphinoids, hadranthine A (1) and hadranthine B (2), together with the known alkaloids imbiline-1 (3), sampangine (4), and 3-methoxysampangine (5), whose structures were determined primarily from 2D-NMR 1H-13C HMBC, and 1H-15N HMBC experiments. This is the first report of the co-occurrence of the copyrine alkaloids 4 and 5, as well as the first report of either copyrine or imbiline type alkaloids from a Duguetia species. Compounds 1, 4, and 5 demonstrated in vitro antimalarial activity against Plasmodium falciparum (W-2 clone), while 2 was inactive. Instead, 2 showed in vitro cytotoxicity to selected human cancer cell lines (IC50 = 3-6 microg/mL against SK-MEL, KB, BT-549, and SK-OV-3), and 4 was also cytotoxic to human malignant melanoma (IC50 = 0.37 microg/mL). Sampangine (4) also inhibited cell aggregation with a MIC value of <0.15 microg/mL, while 3-methoxysampangine (5) was only weakly active.
Asunto(s)
Alcaloides/aislamiento & purificación , Antifúngicos/aislamiento & purificación , Antimaláricos/aislamiento & purificación , Antineoplásicos Fitogénicos/aislamiento & purificación , Plantas Medicinales/química , Alcaloides/farmacología , Animales , Antifúngicos/farmacología , Antimaláricos/farmacología , Antineoplásicos Fitogénicos/farmacología , Brasil , Adhesión Celular/efectos de los fármacos , Agregación Celular/efectos de los fármacos , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Paraguay , Extractos Vegetales/química , Plasmodium falciparum/efectos de los fármacos , Espectrofotometría Ultravioleta , Células Tumorales CultivadasRESUMEN
A new quassinoid, 11-O-trans-p-coumaroyl amarolide (1) was isolated from Castela texana, and the structure was elucidated by spectroscopic analysis. Compound 1 is the first coumaroyl quassinoid derivative to have been isolated from nature. The known compounds amarolide (2), chaparrinone, chaparrin, glaucarubolone, holacanthone, and 15-O-beta-D-glucopyranosyl glaucarubol were also isolated. All isolated compounds were tested for their cytotoxicity and antiprotozoal activities.