de Ávila Janaína M, Dalcol Ionara I, Pereira Alessandra O, Santos Eveline W, Ferraz Adriano, Santos Maura Z, Mostardeiro Marco A, Morel Ademir F
Nucleo de Pesquisa de Produtos Naturais- NPPN, Departamento de Quimica, Universidade Federal de Santa Maria, Santa Maria, Brazil.
Med Chem. 2018;14(8):784-790. doi: 10.2174/1573406414666180524081650.
Several species of the genus Erythrina have been used as sedative, antidepressant, and anticonvulsant. Erythrina crista-galli is native to the Pampa Biome and is widely used for medicinal purposes. Erythrinan alkaloids exhibit a range of pharmacological properties.
The aim of this study was to evaluate the basic fractions and the alkaloids isolated from E. crista-galli bark against a collection of bacteria and fungi for the first time.
Erythrina crista-galli stem bark was extracted with MeOH under reflux. The crude extract was dissolved in water, acidified and extracted with diethyl ether. Basification of the aqueous solution followed by diethyl ether and ethyl acetate extractions gave the basic ether and basic ethyl acetate fractions. Chromatographic purification of these fractions afforded five known alkaloids: erytharbine (1), erysotrine (2), erysotramidine (3), erysotrine N-oxide (4) and erythratidine (5) along with a new alkaloid named here erythratidine N-oxide (6). Alkaloids 1-6 were investigated against a collection of bacteria and fungi using the broth micro dilution method.
In this work, a new alkaloid was isolated from E. crista-galli. The most significant bacterial inhibitory effect of alkaloidal fractions was observed against the Gram-negative Pseudomas aeroginosa (MIC values of 31.25 µg.mL-1). Basic ether fraction displayed good antimicrobial activity against Shigella sonnei with MIC= 62.5 µg.mL-1. Isolated alkaloids 1-6 showed inhibitory activity against all bacteria tested (MIC values of 50-100 µg.mL-1). In addition, the crude extract and alkaloids 1, 2, and 5 also showed good antifungal potential against Candida krusei (MICs between 12.5 and 31.25 µg.mL-1). The previously undescribed alkaloid 6 presented MIC values between 50 and 100 µg.mL-1 against all tested microorganisms.
In general, as with a considerable number of phytochemicals with antimicrobial activity, alkaloids 1-6 may be considered with potential as antibacterial/antifungal agents. The MIC values of the extract, alkaloidal fractions and compounds 1-6 indicate that, at least in part, the isolates were responsible for the antimicrobial activity observed.
刺桐属的几种植物已被用作镇静剂、抗抑郁药和抗惊厥药。鸡冠刺桐原产于潘帕斯生物群落，被广泛用于药用。刺桐生物碱具有一系列药理特性。
本研究旨在首次评估从鸡冠刺桐树皮中分离得到的碱性馏分和生物碱对一系列细菌和真菌的作用。
鸡冠刺桐茎皮用甲醇回流提取。粗提取物溶于水，酸化后用乙醚萃取。水溶液碱化后再用乙醚和乙酸乙酯萃取，得到碱性乙醚馏分和碱性乙酸乙酯馏分。这些馏分经色谱纯化得到5种已知生物碱：刺桐宾（1）、刺桐灵（2）、刺桐曲明（3）、刺桐灵N-氧化物（4）和刺桐定（5），以及一种新生物碱，在此命名为刺桐定N-氧化物（6）。采用肉汤微量稀释法研究了生物碱1-6对一系列细菌和真菌的作用。
在本研究中，从鸡冠刺桐中分离得到一种新生物碱。生物碱馏分对革兰氏阴性菌铜绿假单胞菌的抑菌作用最为显著（MIC值为31.25μg/mL）。碱性乙醚馏分对宋内志贺菌显示出良好的抗菌活性，MIC=62.5μg/mL。分离得到的生物碱1-6对所有测试细菌均显示出抑制活性（MIC值为50-100μg/mL）。此外，粗提取物以及生物碱1、2和5对克鲁斯念珠菌也显示出良好的抗真菌潜力（MIC值在12.5至31.25μg/mL之间）。之前未描述的生物碱6对所有测试微生物的MIC值在50至100μg/mL之间。
总体而言，与许多具有抗菌活性的植物化学物质一样，生物碱1-6可能具有作为抗菌/抗真菌剂的潜力。提取物、生物碱馏分和化合物1-6的MIC值表明，至少部分观察到的抗菌活性是由分离物引起的。
