查看“︁降烟碱”︁的源代码

{{Chembox
| ImageFile = Nornicotine.svg
| ImageSize = 200px
| IUPACName = 3-[(2''S'')-2-Pyrrolidinyl]pyridine
| OtherNames = 去甲烟碱、原烟碱
|Section1={{Chembox Identifiers
| CASNo = 494-97-3
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 83H6L5QD8Z
| PubChem = 91462
| ChemSpiderID = 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
| StdInChI = 1S/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
| StdInChIKey = MYKUKUCHPMASKF-VIFPVBQESA-N
  }}
|Section2={{Chembox Properties
| C=9 | H=12 | N=2
| Appearance = 
| Density = 
| MeltingPt = 
| BoilingPt = 
| Solubility =
  }}
|Section3={{Chembox Hazards
| MainHazards = 
| FlashPt = 
| AutoignitionPt =
  }}
}}

'''降烟碱'''是存在于[[烟草]]等植物的[[生物碱]]，化学式为[[C9H12N2|C<sub>9</sub>H<sub>12</sub>N<sub>2</sub>]]。<ref>{{cite journal | vauthors = 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 | title = Fractionation and Extraction Optimization of Potentially Valuable Compounds and Their Profiling in Six Varieties of Two ''Nicotiana'' Species | journal = Molecules | volume = 27 | issue = 22 | page = 8105 | date = November 2022 | pmid = 36432206 | pmc = 9694777 | doi = 10.3390/molecules27228105 | doi-access = free }}</ref>它的结构与[[烟碱]]相似，但少了一个[[甲基]]，因此又称'''去甲烟碱'''。

降烟碱在腌制、加工烟草时会变为[[1类致癌物]]<ref name=":2">{{Cite web|title=List of Classifications – IARC Monographs on the Identification of Carcinogenic Hazards to Humans|url=https://monographs.iarc.fr/list-of-classifications|access-date=2020-07-22|website=monographs.iarc.fr|archive-date=2020-05-20|archive-url=https://web.archive.org/web/20200520044559/https://monographs.iarc.fr/list-of-classifications|dead-url=no}}</ref>[[N-亚硝基降烟碱|''N''-亚硝基降烟碱]]。<ref>{{cite journal | doi = 10.1073/pnas.0506581102 | title = Conversion of nicotine to nornicotine in Nicotiana tabacum is mediated by CYP82E4, a cytochrome P450 monooxygenase | year = 2005 | last1 = Siminszky | first1 = B. | journal = Proceedings of the National Academy of Sciences | volume = 102 | issue = 41 | pages = 14919–24 | pmid=16192354 | pmc=1253577| doi-access = free }}</ref>降烟碱与口水反应也会产生''N''-亚硝基降烟碱。<ref name=":1">{{cite journal|vauthors=Knezevich A, Muzic J, Hatsukami DK, Hecht SS, Stepanov I|date=February 2013|title=Nornicotine nitrosation in saliva and its relation to endogenous synthesis of N'-nitrosonornicotine in humans|journal=Nicotine & Tobacco Research|volume=15|issue=2|pages=591–5|doi=10.1093/ntr/nts172|pmc=3611998|pmid=22923602}}</ref>

== 合成==
降烟碱可通过用[[氧化银]]将烟碱[[去甲基化]]而成。<ref name="späth">{{cite journal | last1 = Spaeth | title = Über dasd-Nor-nicotin | year = 1936 | journal = [[Chem. Ber.]] | volume = 69 | issue = 2 | pages = 250–251 | doi = 10.1002/cber.19360690207 }}</ref>

<div class="center">[[File:Nicotine2DACS.svg|150px]]<math>\mathrm{  \xrightarrow[H_2O]{Ag_2O} }</math>  [[File:Nornicotin.svg|170px]]</div>

它也可由{{le|麦斯明|myosmine}}的[[催化氢化]]<ref>{{cite journal | last1 = Haines | year = 1945 | title =  Chemical Reactivity of Myosmine| journal = J. Am. Chem. Soc. | volume = 67 | issue = 8 | pages = 1258–1260 | doi = 10.1021/ja01224a011 }}</ref>或被[[硼氢化钠]]还原产生。<ref>{{cite journal | pmid = 11916401 | volume=124 | title=Aqueous aldol catalysis by a nicotine metabolite | year=2002 | journal=J. Am. Chem. Soc. | pages=3220–1 | last1 = Dickerson | first1 = TJ | last2 = Janda | first2 = KD | issue=13 | doi=10.1021/ja017774f}}.</ref>

<div class="center">[[File:Myosmin.svg|150px]]<math>\mathrm{  \xrightarrow[H_2]{Pd/C} }</math>  [[File:Nornicotin.svg|170px]]</div>

== 药学作用==
降烟碱与[[烟碱型乙酰胆碱受体]]的[[亲和力]]高<ref name="pmid17241116">{{cite journal |vauthors=Papke RL, Dwoskin LP, Crooks PA |title=The pharmacological activity of icotine and nornicotine on nAChRs subtypes: relevance to nicotine dependence and drug discovery |journal=Journal of Neurochemistry|volume=101 |issue=1 |pages=160–7 |date=April 2007 |pmid=17241116 |doi=10.1111/j.1471-4159.2006.04355.x |url= |issn=|doi-access=free }}</ref>，会以此抑制大鼠[[纹状体]]的[[多巴胺转运体]]，释放多巴胺。<ref name="pmid17146768">{{cite journal |vauthors=Middleton LS, Crooks PA, Wedlund PJ, Cass WA, Dwoskin LP |title=Nornicotine inhibition of dopamine transporter function in striatum via nicotinic receptor activation |journal=Synapse |volume=61 |issue=3 |pages=157–65 |date=March 2007 |pmid=17146768 |doi=10.1002/syn.20351 |s2cid=35071082 |url= |issn=}}</ref><ref name="pmid11779039">{{cite journal |vauthors=Dwoskin LP, Teng LH, Crooks PA |title=Nornicotine, a nicotine metabolite and tobacco alkaloid: desensitization of nicotinic receptor-stimulated dopamine release from rat striatum |journal=European Journal of Pharmacology|volume=428 |issue=1 |pages=69–79 |date=September 2001 |pmid=11779039 |doi=10.1016/s0014-2999(01)01283-3 |url= |issn=}}</ref><ref name="pmid8492124">{{cite journal |vauthors=Dwoskin LP, Buxton ST, Jewell AL, Crooks PA |title=S(-)-nornicotine increases dopamine release in a calcium-dependent manner from superfused rat striatal slices |journal=Journal of Neurochemistry |volume=60 |issue=6 |pages=2167–74 |date=June 1993 |pmid=8492124 |doi=10.1111/j.1471-4159.1993.tb03502.x |s2cid=25622404 |url= |issn=}}</ref>

== 参考资料==
{{reflist|30em}}

[[Category:生物碱]]
[[Category:吡咯烷]]
[[Category:3-吡啶基化合物]]