Triterpenes from Minquartia guianensis (Olacaceae) and in vitro antimalarial activity

Abstract

Minquartia guianensis, popularly known as acariquara, was phytochemically investigated. The following triterpenes were isolated from the dichloromethane extract of leaves: lupen-3-one (1), taraxer-3-one (2) and oleanolic acid (3). The dichloromethane extract of branches yielded the triterpene 3β-methoxy-lup-20(29)-ene (4). The chemical structures were characterized by NMR data. Plant extracts, substance 3, squalene (5) and taraxerol (6), (5 and 6 previously isolated), were evaluated by in vitro assay against chloroquine resistant Plasmodium falciparum. The dichloromethane extract of leaves and the three triterpenes assayed have shown partial activity. Thus, these results demonstrated that new potential antimalarial natural products can be found even in partially active extracts

Triterpenes from leaves of Cheiloclinium cognatum and their in vivo antiangiogenic activity

“…Even though pentacyclic triterpenes are commonly found in leaves of species of the family Celastraceae and display different pharmacological properties, just a few studies describe its potential as angiogenesis inhibitors . Angiogenesis is a natural growth of new blood vessels from preexisting vessels.…”

Triterpenes, steroids and phenolic isolated from Minquartia guianensis Aubl. (Coulaceae) and antibacterial activity

“…Para o triterpeno 1, no espectro de RMN de 1 H pode-se destacar os sinais em δ 4,69 e 4,57 referentes aos 2 hidrogênios da ligação dupla terminal (H-29). Nos espectros de RMN de 13 C e DEPT 135º, verificou-se o sinal em δ 150,9 referente ao carbono quaternário e em δ 109,4 sinal de CH2 da ligação dupla, e em δ 218,3 foi observado a presença da carbonila (CURSINO et al, 2012). Para o triterpeno 2, no espectro de RMN de 1 H pode-se destacar sinais dos hidrogênios no C-2 próximos ao grupo carbonila na região de δ 2,25 -2,60, além do sinal em δ 5,21 (t, 1H, J = 3,6 Hz), indicando a presença do triterpeno com esqueleto oleanano.…”

“…Triterpeno isolado na fração 11. No espectro de RMN de 1 H, pode-se destacar a ligação dupla pela presença de um sinal em δ 5,51 (dd, J = 8,5 e 3,5 Hz) e nos espectros de RMN de 13 C e DEPT 135º sinais correspondentes ao carbono quaternário em δ 158,0 e CH em δ 116,87 que confirmam ser o taraxerol, os demais sinais foram compatíveis com a estrutura proposta (CURSINO et al, 2012).…”