da Silva Vagner Pereira, Oliveira Rodrigo Rodrigues, Figueiredo Maria Raquel
Laboratório de Química de Produtos Naturais, Far-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
Phytochem Anal. 2009 Jan-Feb;20(1):77-81. doi: 10.1002/pca.1100.
Limonoids are tetranortriterpenoids of considerable interest due to their structural varieties and biological activities, such as insecticidal, antibacterial, antifungal, antimalarial, anticancer and antiviral. They contain oxygen atoms that confer a moderate polarity and are responsible for the difficulties in their separation by traditional chromatographic methods. High-speed countercurrent chromatography (HSCCC) is a versatile liquid-liquid separation technique, in which the sample is distributed between two non-miscible phases to achieve separation.
To isolate limonoids from a complex Carapa guianensis seed extract by gradient elution HSCCC and to identify them by spectrometric and spectroscopic methods.
The hexane extract of Carapa guianensis squeezed seeds was prepared by Soxhlet extraction. From this extract, 800 mg were submitted to gradient mode HSCCC, using the solvent systems hexane:ethyl acetate:methanol:water 1:2:X:1, X = 1.5 (system A) and X = 1.75 (system B). The upper organic phase of the system A was used as stationary phase, and the lower aqueous phases of both systems as mobile phases. In this procedure, 165 fractions of 4 mL (660 mL) were collected.
Six compounds were isolated. Spectrometric and spectroscopic analysis allowed the identification of the substances, as follows: methyl angolensate (28.7 mg), 7-deacetoxy-7-oxogedunin (17.9 mg), deacetylgedunin (3.7 mg), 6alpha-acetoxygedunin (40.1 mg), gedunin (21.0 mg), and andirobin (5.8 mg).
The use of gradient mode in HSCCC was a good alternative, exploiting small variations of partition coefficient between the substances. Thus it was possible to isolate them in a good relative abundance, compared with classical chromatographic methods.
柠檬苦素是一类具有重要意义的四环三萜类化合物，因其结构多样且具有生物活性，如杀虫、抗菌、抗真菌、抗疟疾、抗癌和抗病毒活性。它们含有赋予适度极性的氧原子，这使得用传统色谱方法分离它们存在困难。高速逆流色谱法（HSCCC）是一种通用的液 - 液分离技术，其中样品在两个不混溶的相之间分配以实现分离。
通过梯度洗脱高速逆流色谱法从复杂的圭亚那卡拉帕种子提取物中分离柠檬苦素，并通过光谱和波谱方法对其进行鉴定。
采用索氏提取法制备圭亚那卡拉帕压榨种子的己烷提取物。从该提取物中取800 mg进行梯度模式高速逆流色谱分离，使用的溶剂系统为己烷：乙酸乙酯：甲醇：水1:2:X:1，X = 1.5（系统A）和X = 1.75（系统B）。系统A的上层有机相用作固定相，两个系统下层的水相用作流动相。在此过程中，收集了165份4 mL（共660 mL）馏分。
分离出六种化合物。通过光谱和波谱分析鉴定出这些物质如下：安哥拉酸甲酯（28.7 mg）、7 - 脱乙酰氧基 - 7 - 氧代格杜宁（17.9 mg）、脱乙酰格杜宁（3.7 mg）、6α - 乙酰氧基格杜宁（40.1 mg）、格杜宁（21.0 mg）和安迪罗宾（5.8 mg）。
在高速逆流色谱法中使用梯度模式是一种很好的选择，利用了不同物质之间分配系数的微小差异。因此，与经典色谱方法相比，能够以较好的相对丰度分离出这些物质。
