Chemical constituents from Terminalia glabrescens

Abstract

Das folhas de Terminalia glabrescens foram obtidos um novo triterpeno pentacíclico (3β,6β,23,28-tetraidroxiolean-12-eno), além dos ácidos ursólico, 2α-hidroxiursólico, oleanólico, maslínico, arjunólico, sumaresinólico e asiático, esqualeno, fitol, sitosterol-3-O-β-D-glucopiranosídeo e nalcanos. Da casca do caule foram obtidos friedelina, taraxerol, lupeol, lupenona, betulina, betulona, ácido betulínico, arjunglucosídeo I, estigmastano-3β,6α-diol, β-sitosterol, (-) catequina, β-Dpiranotagatose, β-D-furanofrutose e α-D-furanofrutose.A new oleanane-type triterpene (3β,6β,23,28-tetrahydroxyolean-12-ene) was isolated from the leaves of Terminalia glabrescens, together with ursolic, 2α-hydroxyursolic, oleanolic, maslinic, arjunolic, sumaresinolic and asiatic acids, squalene, phytol, sitosterol-3-O-β-D-glucopyranoside and n-alkanes. Friedelin, taraxerol, lupeol, lupenone, betulin, betulone, betulinic acid, arjunglucoside I, stigmastane-3β,6α-diol, β-sitosterol, (-) catechin, β-D-pyranotagatose, β-D-furanofructose and α-D-furanofructose were obtained from the trunk bark. Combretaceae, triterpenes, 3β,6β,23, Keywords: Terminalia glabrescens, IntroductionPlants of the genus Terminalia (Combretaceae) are known as a rich source of secondary metabolites, such as pentacyclic triterpenes and their glycoside derivatives, flavonoids, tannins and other aromatic compounds, some of which with antibacterial, antifungal, anticancer and hepatoprotective activities. 1-8Terminalia glabrescens Mart., which has not previously been chemically investigated, is a medium-sized tree widespread in Mato Grosso do Sul, Brazil. In the present paper, we describe the isolation and structural elucidation of a new oleanane-type triterpene (3β,6β,23,28-tetrahydroxyolean-12-ene) from the leaves of this species. The known pentacyclic triterpenes ursolic, 2α-hydroxyursolic, oleanolic, maslinic, arjunolic, sumaresinolic and asiatic acids together with squalene, phytol, sitosterol-3-O-β-Dglucopyranoside and foliar wax hydrocarbons were also obtained from the leaves, while the trunk bark afforded the triterpenes friedelin, taraxerol, lupeol, lupenone, betulin, betulone, betulinic acid and arjunglucoside I in addition to stigmastane-3β,6α-diol, β-sitosterol, (-) catechin, β-D-pyranotagatose, β-D-furanofructose and α-D-furanofructose.The structures of the known and new compounds were established on the basis of spectral data, mainly 1 H and 13 C (1D and 2D) NMR spectra and by comparison with authentic samples. Results and DiscussionThe hexane and CHCl 3 solubles obtained from partition of the ethanol extract of leaves were subjected to a series of normal and reversed phase silica gel column chromatography, gel filtration and preparative TLC on silica gel separations to yield the new pentacyclic triterpene 3β,6β,23,28-tetrahydroxyolean-12-ene (1) in addition to ursolic, 9 oleanolic, 9 2α-hydroxyursolic, 9 maslinic, 9 sumaresinolic (2), 9 asiatic (3) 9 and arjunolic (4) 9 acids, squalene, 10 phytol, sitosterol-3-O-β-D-glucopyranoside and long chain hydrocarbons...

Cytotoxic and Antimicrobial Activities of Two New Triterpenoids From the Peels of Local Egyptian Malus Domestica L.

“…Therefore, the structure of the isolated compound (Figure 1) was assigned based on the chemical shifts obtained from 1D, 2D ( 1 H and 13 C NMR) which revealed the presence of 30 carbons typical of friedelane skeleton. [18][19][20] To the best of our knowledge, this is the first report of the presence of friedelin in peels M. domestica. Compound 2 was identified as betulinic acid respectively, by comparison of their NMR, MS and physical data with those described in the literature.…”

Triterpenóides pentacíclicos das folhas de Terminalia brasiliensis

“…A configuração β-axial para a segunda hidroxila, ligada a C-6, foi definida pelo sinal em δ 4,58 (1H, sl, W h/2 = 9 Hz), indicativo de hidrogênio α-equatorial e consistente com o relatado na literatura para triterpenóides 6β-substituídos 2,9,10 . A análise dos dados disponíveis para o triterpenóide 1 permitiu identificá-lo como o 3β,6β-diidroxi-olean-12-eno.…”

“…Os dois gêneros de maior ocorrência são Combretum e Terminalia, cada um com 250 espécies, sendo extensamente usadas na medicina tradicional da África 1 . As plantas do gênero Terminalia são amplamente distribuídas nas áreas tropicais do mundo e conhecidas como uma fonte rica de metabólitos secundários, tais como triterpenóides pentacíclicos e seus derivados glicosilados, flavonóides, taninos e outros compostos aromáticos 1,2 . As espécies do gênero Terminalia apresentam diversas atividades farmacológicas reveladas pelos extratos ou substâncias isoladas, tais como antifúngica, antimicrobiana, antioxidante, antidiabética, anti-HIV-1, antimalárica e outras 3 .…”

Genus Terminalia: A phytochemical and Biological Review

“…Phytochemical studies performed on different Terminalia species have demonstrated the occurrence of several classes of active constituents, such as tannins, pentacyclic triterpenes and their glycoside derivatives, flavonoids and other phenolic compounds [10].…”