Introduction: Oleander (Nerium oleander and Nerium indicum) is a relatively small evergreen tree of an Indian origin, and growing in Honshu, Shikoku, Kyushu and Okinawa islands in Japan. The plant contains cardiac glycosides in its leaves, stems and flowers and is known as one of poisonous plants; poisoning and fatal cases for domestic animals and humans due to ingestion of this plant were reported [1–6]. The main toxin of oleander is oleandrin. Oleandrin can be measured using cross-reaction of an immunoassay kit for digoxin [1], TLC [2], HPLC [7, 8] and LC/MS [3, 6]. Oleandrin is thermolabile; it is difficult. | 6 Oleander toxins by Chiaki Fuke and Tomonori Arao Introduction Oleander Nerium oleander and Nerium indicum is a relatively small evergreen tree of an Indian origin and growing in Honshu Shikoku Kyushu and Okinawa islands in Japan. The plant contains cardiac glycosides in its leaves stems and flowers and is known as one of poisonous plants poisoning and fatal cases for domestic animals and humans due to ingestion of this plant were reported 1-6 . The main toxin of oleander is oleandrin. Oleandrin can be measured using cross-reaction of an immunoassay kit for digoxin 1 TLC 2 HPLC 7 8 and LC MS 3 6 . Oleandrin is thermolabile it is difficult to analyze it by GC or GC MS because it gives 4 peaks due to decomposition. In this chapter a method for LC MS analysis of oleandrin and its metabolite desacetyloleandrin 9 together with their related compounds such as oleandrigenin and gitoxigenin contained in human specimens is presented. The structures and their molecular weights of oleandrin and its related compounds are shown in Figure . Ri r2 O-CO-CH3 . 576 oleandrin HO O ThTh desacetyloleandrin OCH3 OH 534 oleandrigenin H o-co-ch3 432 gitoxgenin H OH 390 digitoxigenin H H 374 Structures and molecular weights of oleandrin and its related compounds. Reagents and their preparation A 1-mg aliquot each of oleandrin oleandrigenin desacetyloleandrina gitoxigenin and digitoxigenin Sigma St. Louis MO USA is dissolved in 10 mL acetonitrile 100 pg mL separately. A volume of the above digitoxigenin solution is diluted with acetonitrile to 10 mL 1 pg mL internal standard IS . Springer-Verlag Berlin Heidelberg 2005 520 Oleander toxins HPLC conditions Instrument a Hitachi M-8000 type LC 3DQMS system column GH-C18 III 150 x mm . particle size 5 pm Hitachi Ltd. Tokyo Japan column temperature 40 C mobile phase methanol water 6 4 v v its flow rate mL min. MS conditions Ionization sonic spray ionization SSI b shield temperature 250 C aperture-1 temperature 150 C
