Chemical constituents from branches of Maytenus gonoclada (Celastraceae) and evaluation of antimicrobial activity

Abstract

Seis triterpenos pentacíclicos isolados dos galhos de Maytenus gonoclada (Celastraceae), incluindo todos os dados de RMN do novo composto 3-oxo-12α,29-diidroxifriedelano são aqui relatados. A estereoquímica do novo friedelano foi estabelecida por dados de RMN bidimensional (HSQC, HMBC e NOESY), e sua massa molecular confirmada por espectrometria de massas (ESI). Testes de atividade antimicrobiana usando método de difusão em disco e de macrodiluição foram realizados contra as bactérias Escherichia coli, Citrobacter freundii e Bacillus cereus, e contra o fungo Candida albicans. O triterpeno 3-oxo-12α-hidroxifriedelano mostrou resultado positivo contra C. albicans.Six pentacyclic triterpenes were isolated from branches of Maytenus gonoclada (Celastraceae) and all NMR data of a new compound 3-oxo-12α,29-dihydroxyfriedelane are herein reported. The stereochemistry of the new friedelane was established by bidimensional NMR (HSQC, HMBC and NOESY) data, and its molecular weight confirmed by ESI mass spectrometry. Antimicrobial activity assays using the method of disk diffusion and macrodilution were carried out against the bacteria Escherichia coli, Citrobacter freundii, and Bacillus cereus, and against the fungi Candida albicans. The triterpene 3-oxo-12α-hydroxyfriedelane showed positive result against C. albicans. Celastraceae, antimicrobial activity Keywords: Maytenus gonoclada, IntroductionCelastraceae family contains many species that have been extensively studied in function of their use in traditional medicine. Some species of Maytenus genus are worldwide distributed and have been used by Africans to treat cancer, by Asian people as an insecticide, 1 and by the South American people on the treatment of gastrointestinal diseases. 2 The biological activities associated to Maytenus species have been assigned to different classes of secondary metabolites such as phenolic glucosides, 3 flavonoids 4 and triterpenes. 5 Pentacyclic triterpenes (PCTT) have been commonly isolated from species of the Celastraceae family, and some of them, like 3-oxofriedelane and 3β-hydroxyfriedelane, are considered taxonomic markers of Maytenus genus. 4 A large number of pharmacological activities has been associated to triterpenes isolated from species of the Maytenus genus, such as, 3,15-dioxo-21α-hydroxyfriedelane, isolated from Maytenus robusta, that showed antiulcerogenic activity, 6 and maytenfolic acid, isolated from Maytenus heterophylla, that showed growth inhibitory effect on Candida albicans. 7 Maytenus gonoclada Martius, popularly known as "tiuzinho", can be found in regions of "cerrado" and rupestrian fields of Southeastern and Northeastern Brazil. In our previous studies of the hexane extract from M. gonoclada leaves, the occurrence of five PCTT of the friedelane series was reported. 8 Chemical Constituents from Branches of Maytenus gonoclada (Celastraceae) J. Braz. Chem. Soc. 944 The present paper reports the phytochemical study of hexane extract from branches of M. gonoclada, which was isolated five known triterpene...

Análise quimiométrica usando RMN de 13C como ferramenta para diferenciar duas espécies de Maytenus

“…A literature review was performed in order to obtain the 13 C NMR chemical shifts of the triterpenes from leaves and branches of M. gonoclada and M. robusta (OLIVEIRA et al, 2007;SILVA et al, 2011a;SILVA et al, 2011b;SILVA et al, 2013, NIERO et al, 2006SOUSA et al, 2012a;SOUSA et al, 2012b). The compounds (13 triterpenes for each species) were analyzed based on the chemical shifts of the carbon atoms C1 to C30, generating a matrix.…”

A New Friedelane Triterpenoid from the Branches of Maytenus Gonoclada (Celastraceae)

“…H-28 (δ H 1.33) and it was consistent with a friedelane triterpene skeleton. 4,5,8 In the NOESY contour map, it was observed that the signal of H-18 (δ H 2.41) was correlated with the signals of H-12ax (δ H 3.98) and H-26 (δ H 1.22). The H-12 (δ H 3.98) showed correlations between the signals for H-25 (δ H 0.99) and H-26 (δ H 1.22), indicating that H-12 was in an axial position (Fig.…”

“…Previously, friedelane triterpenes such as 3-oxofriedelane, 3β-hydroxyfriedelane, 3,11-dioxofriedelane, 3,16-dioxofriedelane, 3-oxo-12α-hydroxyfriedelane and 3-oxo-12α,29-dihydroxyfriedelane have been isolated from M. gonoclada. 4,5 Because of the range of pharmacological activities attributed to the triterpenes isolated from species of the Maytenus genus, 6,7 we studied the chloroform extract of branches of M. gonoclada in continuation of our investigation of bioactive compounds. A new friedelane triterpene, 3,16-dioxo-12α-hydroxyfriedelane 1, was isolated together with nine known compounds identified as 3,11-dioxofriedelane 2, 8 3,16-dioxofriedelane 3, 5,8 3,12dioxofriedelane 4, 9 3-oxo-12α,29-dihydroxyfriedelane 5, 5 3-oxofriedelane (friedelin) 6, 10 3β-hydroxyfriedelane 7, 11 3oxo-12α-hydroxyfriedelane 8, 4 3β-hydroxylup-20(29)-ene (lupeol) 9 8 and a mixture of long chain hydrocarbons 10 (Fig.…”

Zika Virus Activity of the Leaf and Branch Extracts of Tontelea micrantha and Its Hexane Extracts Phytochemical Study

“…Phytochemical studies of the Celastraceae family led to the isolation of many bioactive secondary metabolites such as flavonoids, steroids and different classes of pentacyclic triterpenes. Also, many reports describe pharmacological properties of triterpenes like anti-inflammatory, 6,7 antiulcerogenic, 8 analgesic, 9 antibacterial, antifungal, antiviral, antiparasitic, antioxidant, hepatoprotective, neuroprotective, insecticidal and others. 10 Moreover, some species are already employed in the treatments of gastric ulcers, presenting anti-inflammatory and analgesic activities such as Maytenus ilicifolia Mart.…”

“…The fractions C35-43 (CHCl 3 :EtOAc 85:15, 0.77 g) were submitted to a new CC (D, 78 fractions of the 15 mL) yielding 7 (5.2 mg) from the fraction D43 (CHCl 3 :EtOAc 98:2) and friedelan-1,3,21-trione (1) (535.0 mg) from the fractions D45-50 (CHCl 3 :EtOAc 85:15). The fractions B198-245 (CHCl 3 :EtOAc 80:20, 1.17 g) were re-chromatographed on silica gel CC (E, 81 fractions of the 15 mL) providing a mixture (467.6 mg) of 30-hydroxyfriedelan-3-one(8) and 21α-hydroxyfriedelan-3-one (9) from the fractions E40-44 (CHCl 3 :EtOAc 85:15). This mixture was purified on flash silica CC (F, 107 fractions of the 10 mL) yielding 8 (165.0 mg) from the fractions F64-67 (CHCl 3 :EtOAc 90:10).Part of the greenish solid from hexane leaf extract free of gutta (HLE) (14.0 g) was chromatographed on silica gel CC (G) furnishing 102 fractions of 200 mL.…”