Effects of aminoguanidine on γ-aminobutyric acid accumulation pathways in fresh tea leaves under hypoxic conditions

Aminoguanidine (AG), a specific inhibitor of diamine oxidase (DAO), can be used to investigate the γ-aminobutyric acid (GABA) accumulation pathways. The effect of AG on GABA accumulation pathways of tea fresh leaves remains to be explored. Our results indicated AG concentration did not significantly affect GAD activity, but high concentration solution made GABA-T activity increase. AG (1 mm ) maximally, but not entirely, blocked the polyamine degradation pathway, but had no effect on GAD and GABA-T. The polyamine degradation pathway was responsible for 26.8% and 17.0% of GABA formation under hypoxic conditions involving immersion and immersion–vacuum, respectively, because DAO and PAO activity was not completely inhibited.     

3-氨基-1H-1,2,4-三氮唑的合成工艺研究

以氨基胍碳酸盐和甲酸为原料,经成盐、酰化、环合反应得到3-氨基-1H-1,2,4-三氮唑.研究优化了反应时间、反应温度、共沸脱水体系以及产品精制溶剂等工艺条件,产品纯度达到99%,收率85%以上.     

1-甲基-5-硝胺基四唑氨基胍盐的合成研究

以5-氨基四唑为原料,经甲基化和硝化反应制得1-甲基-5-硝亚氨基四唑,然后与氨基胍碳酸氢盐反应得到1-甲基-5-硝亚氨基四唑氨基胍盐。考察了反应温度、时间、物料摩尔比、碱用量和溶剂用量对甲基化反应的影响,优化后产率达44%;还考察了硝化剂用量、反应温度、时间对1-甲基-5-硝亚氨基四唑合成的影响,优化后最高产率为81%。并通过1HNMR、IR、MS等手段对产物进行了表征。