四甲尿酸

四甲尿酸（Theacrine）全名是1,3,7,9-四甲基尿酸，是由古布阿苏（英语：Cupuaçu）及茶树叶子上提炼的生物碱^[1][2]。四甲尿酸有抗炎性及镇痛的效果，其结构类似咖啡因，也会以类似的方式影响腺苷的信号^[2][3]。一般认为在茶叶上，四甲尿酸是由三步骤的路径，由咖啡因所合成^[2]。

四甲尿酸
IUPAC名 1,3,7,9-Tetramethylpurine-2,6,8-trione
别名	1,3,7,9-Tetramethyluric acid; Temurin; Temorine; Tetramethyluric acid; Tetramethyl uric acid
识别
CAS号	2309-49-1  N
PubChem	75324
ChemSpider	67862
SMILES	CN1C2=C(N(C1=O)C)N(C(=O)N(C2=O)C)C
InChI	1/C9H12N4O3/c1-10-5-6(11(2)8(10)15)12(3)9(16)13(4)7(5)14/h1-4H3
InChIKey	QGDOQULISIQFHQ-UHFFFAOYAN
性质
化学式	C9H12N4O3
摩尔质量	224.22 g·mol−1
若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

维基百科中的医学内容仅供参考，并不能视作专业意见。如需获取医疗帮助或意见，请咨询专业人士。详见医学声明。

结构类似咖啡因

四甲尿酸很类似咖啡因，差异只有一个酮基，以及在9-碳上的甲基基团。

安全性

临床实验显示，健康人类可以每日安全服用 300 mg 四甲尿酸持续 8 周，且不会产生习惯。^[4]实验中未发现四甲尿酸具有咖啡因等其他兴奋剂的快速耐受现象。^[4]

在动物实验中，四甲尿酸的LD₅₀为 810 mg/kg，^[5][4]高于咖啡因的 265 mg/kg。^[6]

相关条目

• Liberine（英语：Liberine）
• Methylliberine（英语：Methylliberine）
• 可可碱
• 茶碱

参考资料

1. Zheng, XQ; Ye, CX; Kato, M; Crozier, A; Ashihara, H. Theacrine (1,3,7,9-tetramethyluric acid) synthesis in leaves of a Chinese tea, kucha (Camellia assamica var. Kucha). Phytochemistry. 2002, 60 (2): 129–34. PMID 12009315. doi:10.1016/s0031-9422(02)00086-9.
2. Feduccia, Allison A.; Wang, Yuanyuan; Simms, Jeffrey A.; Yi, Henry Y.; Li, Rui; Bjeldanes, Leonard; Ye, Chuangxing; Bartlett, Selena E. Locomotor activation by theacrine, a purine alkaloid structurally similar to caffeine: Involvement of adenosine and dopamine receptors. Pharmacology Biochemistry and Behavior. 2012, 102 (2): 241. doi:10.1016/j.pbb.2012.04.014.
3. Wang, Yuanyuan; Yang, Xiaorong; Zheng, Xinqiang; Li, Jing; Ye, Chuangxing; Song, Xiaohong. Theacrine, a purine alkaloid with anti-inflammatory and analgesic activities. Fitoterapia. 2010, 81 (6): 627–31. PMID 20227468. doi:10.1016/j.fitote.2010.03.008.
4. Taylor L, Mumford P, Roberts M, Hayward S, Mullins J, Urbina S, Wilborn C. Safety of TeaCrine®, a non-habituating, naturally-occurring purine alkaloid over eight weeks of continuous use. Journal of the International Society of Sports Nutrition. 2016, 13: 2 [2016-05-14]. PMC 4711067 . PMID 26766930. doi:10.1186/s12970-016-0113-3. （原始内容存档于2016-06-04）.
   • These findings support the clinical safety and non-habituating neuro-energetic effects of TeaCrine® supplementation over 8 weeks of daily use (up to 300 mg/day). Moreover, there was no evidence of a tachyphylactic response that is typical of neuroactive agents such as caffeine and other stimulants.
   • Specifically, the acute toxicity for theacrine ingestion in mice has been previously reported [4] to be an LD50 of 810.6 mg/kg, which would equate to roughly 4.0 g for an individual weighing 76 kg.
5. Wang Y, Yang X, Zheng X, Li J, Ye C, Song X. Theacrine, a purine alkaloid with anti-inflammatory and analgesic activities (PDF). Fitoterapia. 2010, 81 (6): 627–31 [2016-05-15]. PMID 20227468. doi:10.1016/j.fitote.2010.03.008. （原始内容存档 (PDF)于2017-09-01）. the result of the acute toxicity test showed that the LD(50) of theacrine was 810.6 mg/kg (769.5-858.0mg/kg).
6. Warszawski D, Gorodischer R, Kaplanski J. Comparative toxicity of caffeine and aminophylline (theophylline ethylenediamine) in young and adult rats. Biology of the Neonate. 1978, 34 (1-2): 68–71. PMID 698326. doi:10.1159/000241107. In adult rats, the LD50 of caffeine and aminophylline was the same after 24 h and after 1 week of observation: caffeine 265 mg/kg