【摘要】 目的：在模拟人胃液条件下，观察野生马齿苋对Ｎ－二甲基亚硝胺（ＮＤ－ＭＡ）体外合成的阻断作用。方法：通过测定ＮＤＭＡ的合成量、ＮＯ－２形成量和消除率，探讨其作用机理。结果：鲜马齿苋汁和马齿苋籽汁均能明显阻断ＮＤＭＡ的化学合成，其抑制率分别为７０．４％和４７．６％。经煮沸５ｍｉｎ后的马齿苋汁的抑制作用减小，其抑制率为３７．９％；鲜马齿苋汁、煮汁和马齿籽汁的剂量与ＮＤＭＡ的合成呈显著的负相关，相关系数分别为－０．９２０（Ｐ＜０．０５）、－０．９９５（Ｐ＜０．０１）和－０．９９３（Ｐ＜０．０１）；马齿苋汁和马齿苋籽汁能抑制亚硝胺合成主要在于二者的有效活性成分（主要为可溶解于水或丙酮中的极性物质）能消除反应液中的亚硝酸盐。结论：野生马齿苋具有明显的抑制亚硝胺合成的作用更多还原

【Abstract】 Objective:The inhibitiory effect on the chemical synthesis of N nitrosodimethylamine by wild purslane in vitro was investigated under simulated human gastric juice.Methods:The mechanism that purslane and its seed juices inhibited nitrosamine synthesis was studied by determining amounts of NDMA synthesized and NO - 2 formed and its elimination rate.Result:The juices of fresh purslane and its seed could obviously inhibit the chemical synthesis of N nitrosodimethylamine（NDMA）,and their inhibition rates were 70.4% and 47.6% respectively.After boiling for 5 minutes,the inhibitory effect of fresh purslane was reduced,and the inhibition rate was 37.9%.The doses of fresh juice,boiled juice and seed juice and the amounts of NDMA synthesized were negatively correlated,and the correlation coefficient were -0.920（P<0.05）,-0.995（P<0.01）and -0.993（P<0.01）respectively.The mechanism that juices of purslane and its seed could inhibit nitrosamine synthesis by the active components,mainly polar substances soluble in water and acetone,acting in NO₂^- elimination.Conclusion:Wild purslane can obviously inhibit nitrosamine synthesis.更多还原