Alkamides and phenethyl derivatives from Aristolochia gehrtii

Abstract

Foram isolados de galhos de Aristolochia gehrtii a cis-N-feruloil-3-O-metildopamina, um derivado hemiacetálico do 5-hidroximetilfurfural, e vinte e dois compostos conhecidos. Entre estes compostos estão cinco lignanas, três terpenos, seis alcalóides dos quais cinco são alcamidas, dois derivados do ácido benzóico e seis derivados constituídos pelo grupo feniletil. As estruturas dos compostos isolados foram determinadas por métodos espectroscópicos e comparação de dados físicos e espectroscópicos dos compostos com aqueles disponíveis na literatura.From the stems of Aristolochia gehrtii, the cis-N-feruloyl-3-O-methyldopamine and a hemiacetal derivative of 5-hydroxymethylfurfural were isolated, together with twenty-two known compounds. These compounds include five lignans, three terpenes, six alkaloids (five alkamides), two benzoic acid derivatives, and six phenethyl derivatives. The structures of the isolated compounds were determined by means of spectroscopic methods and comparison with literature data.

Aristolactams and Alkamides of Aristolochia gigantea

“…Based on the integration of the signals corresponding to the olefinic hydrogens [ cis : δ H-2 5.75 (d, J = 13.0) and δ H-3 6.48 (d, J = 13.0); trans : δ H-2 6.38 (d, J = 15.5) and δ H-3 7.28 (d, J = 15.5)] it was possible to determine that the isolated mixture was in a 1:2 cis / trans proportion. Although cis and trans isomers can isomerize under UV light, both alkamide isomers may be natural compounds [ 26 , 27 ]. To assign with confidence all of the chemical shifts for carbons and hydrogens in the structures, this mixture was exposed to daylight for four hours.…”

Protective effect of Cupressus sempervirens extract against indomethacin-induced gastric ulcer in rats

“…The compound obtained was crystallized directly from appropriate solvents (usually ether or ether-hexane), or if necessary, the compound was subjected to further cleanup by TLC. The solvent systems used and the numbers used to designate them are as follows: 1, methylene chloride; 2, chloroformethyl acetate (2:1); 3, methylene chloride-ether (2:1); 4, benzene-ether (20:1); 5, hexane-ethyl acetate-methanol (551); and 6, methylene chloride-ether (1:l) (Navickiene et al ., 2001 ). This process took two months from ethanolic extract till isolation of cupressuflavone powder.…”

Nitro derivatives and other constituents of Aristolochia melastoma

“…Yellow , 94.9 (C-8), 158.5 (C-9), 105.7 (C-10), 123.0 (C-1'), 114.7 (C-2'), 148.4 (C-3'), 150.9 (C-4'), 116.0 (C-5'), 123.8 (C-6'), 105.0 (C-1''), 73.1 (C-2''), 75.1 (C-3''), 70.1 (C-4''), 75.6 (C-5''), 67.5 (C-6''), 102.0 (C-1'''), 72.1 (C-2'''), 72.3 (C-3'''), 73.9 (C-4'''), 69.8 (C-5'''), 18.0 (C-6'''). Figure 1) were identified as aristolactam AII (1), 10 tyrosol (3), 11 p-hydroxybenzoic acid (4), 12 vanillic acid (5), 13 sodium aristolochate IIIa (6), sodium aristolochate IVa (7), 14 4,5-dioxodehydroasimilobine (8), 15 aristolochic acid II (9), aristolochic acid I (10), sodium aristolochate I (11), 14 sitosterol-3-Oβ-glucopyranoside (12), 11,16 glycerol (13), 17 uridine (14), 18 thalictoside (15), 19 icariside D2 (16), 20 adenosine (17), 21 thalictricoside (18), 22 kaempferol 3-O-β-robinobioside (19), 23 and isorhamnetin 3-O-βrobinobioside (20) 24 based on analyses of their MS, 1 H and 13 C NMR (including DEPT, gNOESY, 1 H-1 H gCOSY, gHMQC, gHMBC, and gNOESY) spectra and on comparisons of their spectrometric data with those reported in the literature. The substituent positions in the structures of these compounds were determined with the assistance of gNOESY and gHMBC experiments.…”