Thaxton Amber, Belal Tarek S, Smith Forrest, DeRuiter Jack, Abdel-Hay Karim M, Clark C Randall
Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA.
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt.
Forensic Sci Int. 2015 Jul;252:107-13. doi: 10.1016/j.forsciint.2015.04.023. Epub 2015 Apr 27.
The GC-MS properties of the synthetic cannabinoid drug of abuse 3-(1-naphthoyl)-1-pentylindole (JWH-018) and all 5 of its' regioisomeric 1-naphthoyl substituted 1-n-pentylindoles are compared in this report. These compounds have the 1-naphthoyl-group attached at each of the possible substituent positions of the indole ring. The six compounds have the same elemental composition C24H23NO and the same substituents attached to the indole ring. The electron ionization mass spectra showed equivalent regioisomeric major fragment ions resulting from cleavage of the groups attached to the central indole nucleus. The characteristic (M-17)(+) fragment ion at m/z 324 resulting from the loss of an OH group was significant in the EI-MS of 3-, 4-, 5- and 6-(1-naphthoyl)-1-pentylindole. Fragment ions occurred at m/z 127 and 155 for the naphthyl and naphthoyl cations common to all six regioisomeric substances. Indole containing fragments produced the cations at m/z 284, 270, 214 and 186. The unique fragment at m/z 141 observed in the 1,2- and 1,7-isomers resulted from a rearrangement involving the two indole substituents to yield the C10H7CH2(+) cation. The major points of EI-MS differentiation of the synthetic cannabinoid JWH-018 from the other five isomers are the high relative abundance of both the m/z 144 ion and the m/z 324 ion in the JWH-018 spectrum. GC separations on a capillary column containing a trifluoropropyl methyl polysiloxane (Rtx-200) stationary phase provided excellent resolution of these six compounds. The elution order appears related to the relative distance between the two indole substituents with the lowest retention associated with minimum distance between the groups attached to the indole nucleus.
本报告比较了合成大麻素滥用药物3-(1-萘甲酰基)-1-戊基吲哚(JWH-018)及其所有5种区域异构体1-萘甲酰基取代的1-正戊基吲哚的气相色谱-质谱特性。这些化合物在吲哚环的每个可能取代位置都连接有1-萘甲酰基。这六种化合物具有相同的元素组成C24H23NO，并且在吲哚环上连接有相同的取代基。电子电离质谱显示，由于连接在中心吲哚核上的基团断裂，产生了等效的区域异构体主要碎片离子。在3-、4-、5-和6-(1-萘甲酰基)-1-戊基吲哚的电子轰击质谱中，因失去一个OH基团而产生的m/z 324处的特征性(M-17)(+)碎片离子很显著。所有六种区域异构体物质共有的萘基和萘甲酰基阳离子的碎片离子出现在m/z 127和155处。含吲哚的碎片产生了m/z 284、270、214和186处的阳离子。在1,2-和1,7-异构体中观察到的m/z 141处的独特碎片是由涉及两个吲哚取代基的重排产生的，以产生C10H7CH2(+)阳离子。合成大麻素JWH-018与其他五种异构体在电子轰击质谱上的主要区别在于，JWH-018质谱中m/z 144离子和m/z 324离子的相对丰度较高。在含有三氟丙基甲基聚硅氧烷(Rtx-200)固定相的毛细管柱上进行气相色谱分离，可对这六种化合物进行出色的分离。洗脱顺序似乎与两个吲哚取代基之间的相对距离有关，保留时间最短与连接在吲哚核上的基团之间的最小距离相关。
