碘乙酸

碘乙酸
	IUPAC名; Iodoacetic acid
別名	2-碘乙酸
識別
CAS號	64-69-7
PubChem	5240
ChemSpider	5050
SMILES	C(C(=O)O)I;
InChI	1/C2H3IO2/c3-1-2(4)5/h1H2,(H,4,5);
InChIKey	JDNTWHVOXJZDSN-UHFFFAOYAA
ChEBI	74571
性質
化學式	C2H3IO2
摩爾質量	185.95 g·mol−1
熔點	81 °C（354 K）
沸點	208 °C（481 K）
pKa	3.12
危險性
	GHS危險性符號;
GHS提示詞	danger
H-術語	H301, H314
P-術語	P280, P260, P301+310+330, P331, P303+361+353, P305+351+338, P310
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

碘乙酸是乙酸的一種衍生物，分子式為C
2H
3IO
2，碘乙酸有毒性和腐蝕性。與許多鹵代烴一樣，碘乙酸是一種烷基化試劑。碘乙酸能與蛋白質中的半胱氨酸殘基反應，常被用於修飾巰基，以防止在蛋白質胱氨酸殘基被還原為半胱氨酸後又重新形成二硫鍵^[2]^[3]。

肽酶抑制劑

碘乙酸是所有半胱氨酸蛋白酶的不可逆抑制劑，其反應機理如下圖所示：

碘乙酸對半胱氨酸肽酶的不可逆抑制機理

與其醯胺衍生物碘乙醯胺相比，碘乙酸鹽的烷基化反應速率更慢。這一現象似乎與常規的化學反應性相悖，有報道稱，起催化作用的組氨酸中的咪唑鎓離子和碘乙酸中的羧基負離子間存在有利的相互作用，藉此解釋碘乙醯胺反應性更強的原因^[2]^[4]。

潛在的癌症療法

有研究表明，碘乙酸具有抗腫瘤效果。2002年，生物化學家F. A. Fahim報告稱，「與正常對照組相比，對腫瘤小鼠的單次碘乙酸治療，能明顯提高血清乳酸脫氫酶（LDH）的活性水平，同時可顯著降低血糖和肝臟總蛋白、RNA和DNA的濃度」^[5]。1975年，有報道稱，碘乙酸可能改善骨髓的免疫應答 ^[6]。1966年，有研究指出，碘乙酸鹽能用於誘導腫瘤細胞的腫瘤免疫^{[註 1]}治療^[7]。

消毒副產物

碘離子是一種天然存在的離子，可以在許多原水中找到，並且極易被污水消毒液所氧化。其中一種氧化產物是次碘酸（HOI或OI⁻），它擁有與環境有機物反應的強反應性，產生碘化消毒副產物（I-DBPs），如碘乙酸。Plewa等人報道的研究表明，碘乙酸被認為是「飲用水內碘（代）酸類消毒副產物中細胞毒性最強的物質之一」，其半數致死量的中位數為10⁻⁵ M。碘乙酸被確認是迄今為止遺傳毒性最強的消毒副產物^[8]。

儘管碘乙酸展現出了潛在致癌物的特徵，但尚未被證實具有致癌性^[9]。碘乙酸的致畸性遠勝其溴、氯化的類似物 ^[10]。其毒性與其作為烷基化劑的特性相關，會輕易地封閉蛋白質中的半胱氨酸殘基^[11]。單鹵乙酸的毒性最強，其毒性隨著鹵原子的大小增加而增加，碘乙酸的毒性強於溴乙酸，遠強於氯乙酸 ^[12]。

腳註

^ tumour immunity

參見

碘乙醯胺

參考文獻

^ Dippy, J. F. J.; Hughes, S. R. C.; Rozanski, A. The dissociation constants of some symmetrically disubstituted succinic acids. Journal of the Chemical Society. 1959: 2492–2498.
^ ^2.0 ^2.1 Smythe CV. The reactions of Iodoacetate and of Iodoacetamide with various Sulfhydryl groups, with Urease, and with Yeast preparations (PDF). J. Biol. Chem. 1936, 114 (3): 601–12.
^ Anson ML. The reactions of Iodine and Iodoacetamide with native Egg Albumin. J. Gen. Physiol. 1940, 23 (3): 321–31. PMC 2237930  . PMID 19873158. doi:10.1085/jgp.23.3.321.
^ Polgár, L. Deuterium isotope effects on papain acylation. Evidence for lack of general base catalysis and for enzyme-leaving group interaction. European Journal of Biochemistry. 1979, 98 (2): 369–374. PMID 488108. doi:10.1111/j.1432-1033.1979.tb13196.x.
^ Fahim, F. A.; Esmat, A. Y.; Mady, E. A.; Ibrahim, E. K. Antitumor Activities of Iodoacetate and Dimethylsulphoxide Against Solid Ehrlich Carcinoma Growth in Mice. Biological Research. 2003, 36 (2): 253–262. PMID 14513720. doi:10.4067/S0716-97602003000200015  .
^ Rhein, M. S.; Filppi, J. A.; Moore, V. S. Effect of Iodoacetate on the Bone Marrow Immunocompetence of AKR Mice (PDF). Cancer Research. 1975, 35 (6): 1514–1519. PMID 1093673.
^ Apffel, C. A.; Arnason, B. G.; Peters, J. H. Induction of tumour immunity with tumour cells treated with iodoacetate. Nature. 1966, 209 (5021): 694–696. Bibcode:1966Natur.209..694A. PMID 5922128. S2CID 4296138. doi:10.1038/209694a0.
^ Plewa, Michael J.; Wagner, Elizabeth D.; Richardson, Susan D.; Thruston, Alfred D., Jr.; Woo, Yin-Tak; McKague, A. Bruce. Chemical and Biological Characterization of Newly Discovered Iodoacid Drinking Water Disinfection Byproducts. Environmental Science & Technology. 2004, 38 (18): 4713–4722. Bibcode:2004EnST...38.4713P. PMID 15487777. doi:10.1021/es049971v.
^ Wei, Xiao; Wang, Shu; Zheng, Weiwei; Wang, Xia; Liu, Xiaolin; Jiang, Songhui; Pi, Jingbo; Zheng, Yuxin; He, Gengsheng; Qu, Weidong. Drinking Water Disinfection Byproduct Iodoacetic Acid Induces Tumorigenic Transformation of NIH3T3 Cells. Environmental Science & Technology. 2013, 47 (11): 5913–5920. Bibcode:2013EnST...47.5913W. PMID 23641915. doi:10.1021/es304786b.
^ Richard, Ann M.; Hunter, E. Sidney, III. Quantitative Structure-Activity Relationships for the Developmental Toxicity of Haloacetic Acids in Mammalian Whole Embryo Culture. Teratology. 1996, 53 (6): 352–360. PMID 8910981. doi:10.1002/(SICI)1096-9926(199606)53:6<352::AID-TERA6>3.0.CO;2-1.
^ Product #35603. Thermo Scientific. Pierce Protein Biology Products. [2023-01-03]. （原始內容存檔於2014-12-31）.
^ Richardson, Susan D.; Plewa, Michael J.; Wagner, Elizabeth D.; Shoeny, Rita; DeMarini, David M. Occurrence, genotoxicity, and carcinogenicity of regulated and emerging disinfection by-products in drinking water: A review and roadmap for research. Mutation Research. 2007, 636 (1–3): 178–242. PMID 17980649. doi:10.1016/j.mrrev.2007.09.001.

延伸閱讀

Knap, A. K.; Pratt, R. F. Inactivation of the RTEM-1 cysteine beta-lactamase by iodoacetate. The nature of active-site functional groups and comparisons with the native enzyme. Biochemical Journal. 1991, 273 (1): 85–91. PMC 1149883  . PMID 1989590. doi:10.1042/bj2730085.
Dickens, F. Interaction of halogenacetates and SH compounds. The reaction of halogenacetic acids with glutathione and cysteine. The mechanism of iodoacetate poisoning of glyoxalase. Biochemical Journal. 1933, 27 (4): 1141–1151. PMC 1253000  . PMID 16745202. doi:10.1042/bj0271141.

[7] tumour immunity

[1] Dippy, J. F. J.; Hughes, S. R. C.; Rozanski, A. The dissociation constants of some symmetrically disubstituted succinic acids. Journal of the Chemical Society. 1959: 2492–2498.

[1936JBC-2] 2.0 ^2.1 Smythe CV. The reactions of Iodoacetate and of Iodoacetamide with various Sulfhydryl groups, with Urease, and with Yeast preparations (PDF). J. Biol. Chem. 1936, 114 (3): 601–12.

[3] Anson ML. The reactions of Iodine and Iodoacetamide with native Egg Albumin. J. Gen. Physiol. 1940, 23 (3): 321–31. PMC 2237930  . PMID 19873158. doi:10.1085/jgp.23.3.321.

[4] Polgár, L. Deuterium isotope effects on papain acylation. Evidence for lack of general base catalysis and for enzyme-leaving group interaction. European Journal of Biochemistry. 1979, 98 (2): 369–374. PMID 488108. doi:10.1111/j.1432-1033.1979.tb13196.x.

[5] Fahim, F. A.; Esmat, A. Y.; Mady, E. A.; Ibrahim, E. K. Antitumor Activities of Iodoacetate and Dimethylsulphoxide Against Solid Ehrlich Carcinoma Growth in Mice. Biological Research. 2003, 36 (2): 253–262. PMID 14513720. doi:10.4067/S0716-97602003000200015  .

[6] Rhein, M. S.; Filppi, J. A.; Moore, V. S. Effect of Iodoacetate on the Bone Marrow Immunocompetence of AKR Mice (PDF). Cancer Research. 1975, 35 (6): 1514–1519. PMID 1093673.

[8] Apffel, C. A.; Arnason, B. G.; Peters, J. H. Induction of tumour immunity with tumour cells treated with iodoacetate. Nature. 1966, 209 (5021): 694–696. Bibcode:1966Natur.209..694A. PMID 5922128. S2CID 4296138. doi:10.1038/209694a0.

[[4]-9] Plewa, Michael J.; Wagner, Elizabeth D.; Richardson, Susan D.; Thruston, Alfred D., Jr.; Woo, Yin-Tak; McKague, A. Bruce. Chemical and Biological Characterization of Newly Discovered Iodoacid Drinking Water Disinfection Byproducts. Environmental Science & Technology. 2004, 38 (18): 4713–4722. Bibcode:2004EnST...38.4713P. PMID 15487777. doi:10.1021/es049971v.

[[7]-10] Wei, Xiao; Wang, Shu; Zheng, Weiwei; Wang, Xia; Liu, Xiaolin; Jiang, Songhui; Pi, Jingbo; Zheng, Yuxin; He, Gengsheng; Qu, Weidong. Drinking Water Disinfection Byproduct Iodoacetic Acid Induces Tumorigenic Transformation of NIH3T3 Cells. Environmental Science & Technology. 2013, 47 (11): 5913–5920. Bibcode:2013EnST...47.5913W. PMID 23641915. doi:10.1021/es304786b.

[[5]-11] Richard, Ann M.; Hunter, E. Sidney, III. Quantitative Structure-Activity Relationships for the Developmental Toxicity of Haloacetic Acids in Mammalian Whole Embryo Culture. Teratology. 1996, 53 (6): 352–360. PMID 8910981. doi:10.1002/(SICI)1096-9926(199606)53:6<352::AID-TERA6>3.0.CO;2-1.

[[9]-12] Product #35603. Thermo Scientific. Pierce Protein Biology Products. [2023-01-03]. （原始內容存檔於2014-12-31）.

[13] Richardson, Susan D.; Plewa, Michael J.; Wagner, Elizabeth D.; Shoeny, Rita; DeMarini, David M. Occurrence, genotoxicity, and carcinogenicity of regulated and emerging disinfection by-products in drinking water: A review and roadmap for research. Mutation Research. 2007, 636 (1–3): 178–242. PMID 17980649. doi:10.1016/j.mrrev.2007.09.001.

[2]

[3]

[1]

[4]

[5]

[6]

[註 1]

[7]

[8]

[9]

[10]

[11]

[12]

碘乙酸


IUPAC名 Iodoacetic acid
別名	2-碘乙酸
識別
CAS號	64-69-7 ^Y
PubChem	5240
ChemSpider	5050
SMILES	C(C(=O)O)I
InChI	1/C2H3IO2/c3-1-2(4)5/h1H2,(H,4,5)
InChIKey	JDNTWHVOXJZDSN-UHFFFAOYAA
ChEBI	74571
性質
化學式	C₂H₃IO₂
摩爾質量	185.95 g·mol⁻¹
熔點	81 °C（354 K）
沸點	208 °C（481 K）
pK_a	3.12^[1]
危險性
GHS危險性符號
GHS提示詞	danger
H-術語	H301, H314
P-術語	P280, P260, P301+310+330, P331, P303+361+353, P305+351+338, P310
若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。