降烟碱

降烟碱是存在于烟草等植物的生物碱，化学式为C₉H₁₂N₂。^[1]它的结构与烟碱相似，但少了一个甲基，因此又称去甲烟碱。

降烟碱
IUPAC名 3-[(2S)-2-Pyrrolidinyl]pyridine
别名	去甲烟碱、原烟碱
识别
CAS号	494-97-3  Y
PubChem	91462
ChemSpider	82588
SMILES	n1cccc(c1)[C@H]2NCCC2
InChI	1/C9H12N2/c1-3-8(7-10-5-1)9-4-2-6-11-9/h1,3,5,7,9,11H,2,4,6H2/t9-/m0/s1
InChIKey	MYKUKUCHPMASKF-VIFPVBQEBM
性质
化学式	C9H12N2
摩尔质量	148.2 g·mol−1
若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

降烟碱在腌制、加工烟草时会变为1类致癌物^[2]N-亚硝基降烟碱。^[3]降烟碱与口水反应也会产生N-亚硝基降烟碱。^[4]

合成

降烟碱可通过用氧化银将烟碱去甲基化而成。^[5]

${\displaystyle \mathrm {\xrightarrow[{H_{2}O}]{Ag_{2}O}} }$

它也可由麦斯明（英语：myosmine）的催化氢化^[6]或被硼氢化钠还原产生。^[7]

${\displaystyle \mathrm {\xrightarrow[{H_{2}}]{Pd/C}} }$

药学作用

降烟碱与烟碱型乙酰胆碱受体的亲和力高^[8]，会以此抑制大鼠纹状体的多巴胺转运体，释放多巴胺。^[9][10][11]

参考资料

1. Laszlo C, Kaminski K, Guan H, Fatarova M, Wei J, Bergounioux A, Schlage WK, Schorderet-Weber S, Guy PA, Ivanov NV, Lamottke K, Hoeng J. Fractionation and Extraction Optimization of Potentially Valuable Compounds and Their Profiling in Six Varieties of Two Nicotiana Species. Molecules. November 2022, 27 (22): 8105. PMC 9694777 . PMID 36432206. doi:10.3390/molecules27228105 .
2. List of Classifications – IARC Monographs on the Identification of Carcinogenic Hazards to Humans. monographs.iarc.fr. [2020-07-22]. （原始内容存档于2020-05-20）.
3. Siminszky, B. Conversion of nicotine to nornicotine in Nicotiana tabacum is mediated by CYP82E4, a cytochrome P450 monooxygenase. Proceedings of the National Academy of Sciences. 2005, 102 (41): 14919–24. PMC 1253577 . PMID 16192354. doi:10.1073/pnas.0506581102 .
4. Knezevich A, Muzic J, Hatsukami DK, Hecht SS, Stepanov I. Nornicotine nitrosation in saliva and its relation to endogenous synthesis of N'-nitrosonornicotine in humans. Nicotine & Tobacco Research. February 2013, 15 (2): 591–5. PMC 3611998 . PMID 22923602. doi:10.1093/ntr/nts172.
5. Spaeth. Über dasd-Nor-nicotin. Chem. Ber. 1936, 69 (2): 250–251. doi:10.1002/cber.19360690207.
6. Haines. Chemical Reactivity of Myosmine. J. Am. Chem. Soc. 1945, 67 (8): 1258–1260. doi:10.1021/ja01224a011.
7. Dickerson, TJ; Janda, KD. Aqueous aldol catalysis by a nicotine metabolite. J. Am. Chem. Soc. 2002, 124 (13): 3220–1. PMID 11916401. doi:10.1021/ja017774f..
8. Papke RL, Dwoskin LP, Crooks PA. The pharmacological activity of icotine and nornicotine on nAChRs subtypes: relevance to nicotine dependence and drug discovery. Journal of Neurochemistry. April 2007, 101 (1): 160–7. PMID 17241116. doi:10.1111/j.1471-4159.2006.04355.x .
9. Middleton LS, Crooks PA, Wedlund PJ, Cass WA, Dwoskin LP. Nornicotine inhibition of dopamine transporter function in striatum via nicotinic receptor activation. Synapse. March 2007, 61 (3): 157–65. PMID 17146768. S2CID 35071082. doi:10.1002/syn.20351.
10. Dwoskin LP, Teng LH, Crooks PA. Nornicotine, a nicotine metabolite and tobacco alkaloid: desensitization of nicotinic receptor-stimulated dopamine release from rat striatum. European Journal of Pharmacology. September 2001, 428 (1): 69–79. PMID 11779039. doi:10.1016/s0014-2999(01)01283-3.
11. Dwoskin LP, Buxton ST, Jewell AL, Crooks PA. S(-)-nornicotine increases dopamine release in a calcium-dependent manner from superfused rat striatal slices. Journal of Neurochemistry. June 1993, 60 (6): 2167–74. PMID 8492124. S2CID 25622404. doi:10.1111/j.1471-4159.1993.tb03502.x.