Kaur S, Grover I S, Singh M, Kaur S
Department of Botanical Sciences, Guru Nanak Dev University, Amritsar 143 005, India.
Mutat Res. 1998 Nov 9;419(1-3):169-79. doi: 10.1016/s1383-5718(98)00130-2.
A tannin fraction (TC-E) from the dried fruit pulp of Terminalia chebula was obtained by successfully extracting with 95% ethyl alcohol and ethyl acetate. TC-E was subjected to silica gel chromatography which yielded four fractions, viz., TC-EI, TC-EII, TC-EIII and TC-EIV. Thin layer chromatography (TLC) and 13C-NMR revealed that TC-EI was gallic acid (GA) derivative while the other fractions were tannin in nature. TC-E and its fractions were evaluated for their antimutagenic potential against two direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and 4-nitroquinoline-N-oxide (4NQNO), and S9-dependent mutagen, 2-aminofluorene (2AF) in TA98 and TA100 strains of Salmonella typhimurium. The study revealed that the extract (TC-E) and its fractions were highly significant against S9-dependent mutagen, 2AF. The effect was found to be more or less corresponding with the nature of the fractions, as the monomeric TC-EI (a GA derivative) was least effective as compared to other fractions which were oligomeric, and the order of their effectiveness as per their IbD50 value being TC-EIV (8.9 micrograms)>TC-EIII (17.8 micrograms)>TC-EII (45 micrograms)>TC-EI (320 micrograms) in TA98; TC-EIV being 40 times more effective than TC-EI in inhibiting his+ revertants. A similar effect was noticed in TA100 too, where TC-EI was the least effective and TC-EII had the maximum effect. A similar result was noticed when the antimutagenicity of GA (a monomeric) was compared with tannic acid (TA, an oligomeric). However, chebula tannins were found to be partly effective against NPD but not at all effective against 4NQNO.
通过用95%乙醇和乙酸乙酯成功提取，从诃子干燥果肉中获得了一种单宁级分（TC-E）。TC-E经过硅胶柱色谱分离得到四个级分，即TC-EI、TC-EII、TC-EIII和TC-EIV。薄层色谱（TLC）和13C-NMR分析表明，TC-EI是没食子酸（GA）衍生物，而其他级分本质上是单宁。对TC-E及其级分针对两种直接作用诱变剂4-硝基邻苯二胺（NPD）和4-硝基喹啉-N-氧化物（4NQNO）以及在鼠伤寒沙门氏菌TA98和TA100菌株中依赖S9的诱变剂2-氨基芴（2AF）的抗诱变潜力进行了评估。研究表明，提取物（TC-E）及其级分对依赖S9的诱变剂2AF具有高度显著的作用。发现该作用或多或少与级分的性质相对应，因为单体的TC-EI（一种GA衍生物）与其他低聚级分相比效果最差，根据它们在TA98中的半数抑制剂量（ID50）值，其有效性顺序为TC-EIV（8.9微克）>TC-EIII（17.8微克）>TC-EII（45微克）>TC-EI（320微克）；在抑制his+回复突变体方面，TC-EIV比TC-EI有效40倍。在TA100中也观察到了类似的效果，其中TC-EI效果最差，而TC-EII效果最大。当将GA（单体）的抗诱变性与单宁酸（TA，低聚物）进行比较时，也观察到了类似的结果。然而，诃子单宁对NPD有部分效果，但对4NQNO完全无效。
