四甲尿酸

四甲尿酸
	IUPAC名; 1,3,7,9-Tetramethylpurine-2,6,8-trione
別名	1,3,7,9-Tetramethyluric acid; Temurin; Temorine; Tetramethyluric acid; Tetramethyl uric acid
識別
CAS號	2309-49-1
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
性質
化學式	C9H12N4O3
摩爾質量	224.22 g·mol−1
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

四甲尿酸（Theacrine）全名是1,3,7,9-四甲基尿酸，是由古布阿蘇（英語：Cupuaçu）及茶樹葉子上提煉的生物鹼^[1]^[2]。四甲尿酸有抗炎性及鎮痛的效果，其結構類似咖啡因，也會以類似的方式影響腺苷的信號^[2]^[3]。一般認為在茶葉上，四甲尿酸是由三步驟的路徑，由咖啡因所合成^[2]。

結構類似咖啡因

四甲尿酸很類似咖啡因，差異只有一個酮基，以及在9-碳上的甲基基團。

安全性

臨床實驗顯示，健康人類可以每日安全服用 300 mg 四甲尿酸持續 8 周，且不會產生習慣。^[4]實驗中未發現四甲尿酸具有咖啡因等其他興奮劑的快速耐受現象。^[4]

在動物實驗中，四甲尿酸的LD₅₀為 810 mg/kg，^[5]^[4]高於咖啡因的 265 mg/kg。^[6]

參考資料

^ 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.
^ ^2.0 ^2.1 ^2.2 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.
^ 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.
^ ^4.0 ^4.1 ^4.2 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. （原始內容存檔於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.
^ 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. （原始內容存檔 (PDF)於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).
^ 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

[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.

[:0-2] 2.0 ^2.1 ^2.2 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.

[pmid26766930-4] 4.0 ^4.1 ^4.2 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. （原始內容存檔於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.

[pmid20227468-5] 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. （原始內容存檔 (PDF)於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).

[pmid698326-6] 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

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結構類似咖啡因

安全性

相關條目

參考資料