Chemical constituents from Luxemburgia nobilis (EICHL)

Abstract

O fracionamento cromatográfico do extrato hexânico dos galhos de Luxemburgia nobilis (Ochnaceae) forneceu β-sitosterol, estigmasterol, ácido betulínico, os ácidos graxos hexadecanóico, tetraeicosanóico, hexaeicosanóico e linoleico, 14-metilpentadecanoato de metila, óxido de 13-epimanoíla, o depsídeo atranorina (1), e dois triglicerídeos novos (2 e 3). As estruturas das substâncias isoladas foram determinadas através da análise dos dados espectroscópicos de I.V., massas e RMN de 1 H e de 13 C incluindo comparação com dados da literatura. A análise do espectro de massas (FAB-MS) dos éteres tiometílicos (4 e 5) foi usada para definir as estruturas dos triglicerídeos.Chromatographic fractionation of the hexane extract from the branches of Luxemburgia nobilis (Ochnaceae) afforded β-sitosterol, stigmasterol, betulinic acid, linoleic acid, methyl-14-methylpentadecanoate, 13-epimanoyl oxide, hexadecanoic acid, tetraeicosanoic acid, hexaeicosanoic acid, the depside atranorin (1) and two new triglycerides (2 and 3). The structures were defined by IR, MS and 1 H-and 13 C-NMR spectral analysis involving comparison with literature data. The FAB-MS spectra analysis of the thiomethyl ethers (4 and 5) were used to define the structures of the triglycerides.

Phytochemical profile of Cespedesia spathulata leaves (Ochnaceae) and its effect on tyrosinase enzyme

“…These analyses led to the identification of compounds 1 to 13 (Table I) in a mixture, and 14, respectively. The position of the double bond in the unsaturated methyl ester (5, Table I) was defined by mass spectrum analyses of the dithiomethyl ether derivative (see discussion) (Carvalho et al 2000). The group containing fractions 24-26 (0.0929 g), obtained with hexane and dichloromethane (50:50), was purified through sephadex-LH20 eluted with dichloromethane and methanol (30:70).…”

Biodiversidade flavonoídica e aspectos farmacológicos em espécies dos gêneros Ouratea e Luxemburgia (Ochnaceae)

“…Além dos flavonóides e biflavonóides, esses gêneros são bioprodutores de outras classes de metabólitos como triterpenos, diterpenos, depsídeos, ésteres graxos e triglicerídeos 17,[20][21][22][23] . Entre essas classes de substâncias, os biflavonóides recebem destaque na literatura, devido à freqüência e abundância com que são encontrados nesses gêneros e cuja diversidade estrutural é devida, principalmente, aos diferentes padrões de ligações entre seus monômeros.…”

Didemnacerides A and B: two new glycerides from Red Sea ascidian Didemnum species

“…The 1 H NMR spectrum exhibited signals for olefinic protons at d H 5.36 (3H, each t, J ¼ 6.0 Hz, H-6 0 , 6 00 , 6 000 ) and 5.34 (3H, each t, J ¼ 6.0 Hz, H-7 0 , 7 00 , 7 000 ) correlated with carbons at d H 129.9 (C-6 0 , 6 000 ), 130.0 (C-6 00 ), 129.8 (C-7 00 ) and 129.7 (C-7 0 , 7 000 ) in the HSQC spectrum, also indicating the presence of three olefinic double bonds in 1. The geometry of the double bonds was deduced to be Z based on the coupling constant values (J 6 0 ,7 0 ¼ J 6 00 ,7 00 ¼ J 6 00 0 ,7 00 0 ¼ 6.0 Hz) (de Carvalho et al 2000;Ibrahim 2014). The 1 H NMR spectrum revealed characteristic signals for the terminal methyl protons of the fatty acids at d H 0.87 (t, J ¼ 6.5 Hz, H-21 00 ) and 0.85 (t, J ¼ 6.5 Hz, H-21 0 , 21 000 ), broad signals at d H 1.23 -1.38 for the methylene protons, two methylene triplets at d H 2.32 (H-2 00 ) and 2.31 (H-2 0 , 2 000 ), and two multiplets at d H 1.63 (H-3 00 ) and 1.61 (H-3 0 , 3 000 ).…”

“…Moreover, the signals at d H 5.35 (2H, dt, J ¼ 6.2 and 5.8 Hz, H-6 0 , 9 0 ), 5.36 (1H, dt, J ¼ 6.2 and 5.8 Hz, H-7 0 ) and 5.34 (1H, dt, J ¼ 6.2 and 5.8 Hz, H-10 0 ) correlated with the carbon signals at d C 129.8 (C-6 0 , 9 0 ), 129.9 (C-7 0 ) and 128.8 (C-10 0 ) indicating the presence of two olefinic double bonds. The geometry of the double bonds was deduced to be Z based on the coupling constant values (J 6 0 ,7 0 and J 9 0 ,10 0 ¼ 5.8 Hz) (de Carvalho et al 2000;Mohamed et al 2013). The signals for methylene group connected to a double bond carbon were observed at d H 2.81 (1H, t, J ¼ 6.2 Hz, H-8 0 )/d C 25.6 (C-8 0 ) and confirmed by its cross-peaks to H-7 0 and H-9 0 in COSY spectrum and with C-6 0 and C-10 0 in the HMBC spectrum.…”