Keywords: 
• LTQ-Orbitrap高分辨质谱(LTQ-Orbitrap MS) /
• 骆驼蓬子 /
• 裂解规律 /
• 生物碱

Abstract: The seed of Peganumharmala Linn .belonging to the family of Zygophylla‐ceae ,is a perennial herb w hich grow s in semi‐arid condition ,steppe area and sandy soil . In China , Peganumharmala as a folk medicine has been used since antiquity among the Uighur ,Kazakh and Mongolia for the treatment of cold ,asthma ,malaria ,rheumatism , lumbago and some skin diseases such as scabies .The content of total alkaloids in ripe seeds could reach as high as 6% mainly in the form of harmaline and harmine ,w hich were the first isolated in the last century .The problem was that the type and content of the rest of the alkaloids in the seeds of Peganumharmala were unknown .The aim of this work was to identify chemical constituents in the methanolic extract found in Peganumharmala .The extract of seeds of Peganumharmala were analyzed using high performance liquid chromatography coupled with high‐resolution mass spectrometry . Chromatographic separation was achieved on a C18 column with the mobile phase of ace‐tonitril‐water (0.5% ammonia water) and step gradient elution .The ESI‐MS analysis was operated at the range of m/z 100‐1 000 in positive ionization mode .High‐resolution mass spectrometry techniques have proven to be a reliable tool for the structural elucida‐tion of unknown compounds in complex samples .In this context ,linear ion trap quadru‐pole‐Orbitrap‐mass spectrometry (LTQ‐Orbitrap MS) provides single‐stage mass analy‐sis that supplies molecular weight information and multi‐stage mass analysis (MSn) that provides structural information .Moreover ,accurate mass measurement of the product ions facilitates the elucidation of unknown compounds . A total of twenty‐two com‐pounds of seeds are identified from the methanolic extract in the seeds of Peganum‐harmala ,such as 10 isoquinoline alkaloid and 10 quinazolone alkaloids ,w hich are char‐acterized in the methanolic extract ,based on the accurate mass of molecular and product ions provided by LTQ‐Orbitrap mass spectrometer .As far as we know ,these com‐pounds have been recognized in seeds of Peganumharmala for the first time ,such as glycosides vasicine ,glycosides pegamine ,3‐hydroxylated harmine .T he method is rapid and simple in the qualitative analysis of licorice using LC‐LTQ‐Orbitrap MS ,which could prove to have a high sensitivity and the result is accurate and reliable .It is an effective method to provide chemical information concerning the constituents in herbal medicines ,w hich could be helpful for the quality control and further phytochemical studies of seeds of Peganumharmala L .