Journal of the Chemical Society - Faraday Transactions p. 1095 - 1098 (1994)
Update date:2022-07-29
Topics:
Brzezinski, Bogumil
Olejnik, Jerzy
Zundel, Georg
We obtained the 2-N-methylaminoethylguanidine amide, 4, of Kemp's triacid (all-cis-1,3,5-trimethylcyclohexane 1,3,5-tricarboxylic acid) as a model substance for the active site of bacteriorhodopsin.Compound 4 was synthesised from Kemp's triacid triethyl ester, 1, in three reactions.Compound 4 and its complex with tetrabutylammonium 4-methylphenolate were studied by FTIR and 1H NMR spectroscopy in acetonitrile solutions.In the case of compound 4, two types of hydrogen bond are formed: one is the CO2H...N ->/<- CO2(-)...H(+)N bond.In this case, the donor is one of the two carboxylic acid groups, and the acceptor, the guanidine group.A double-minimum proton potential is present in this bond and therefore it exhibits large proton polarizability.The second NH...O=C hydrogen bond formed between the protonated guanidine (proton donor group) and the carbonyl O atom of the other carboxylic group is asymmetrical.The proton is localised at the guanidine residue.If a phenolate molecule is added to the solution of compoud 4, the situation changes dramatically.A PhOH...N ->/<- PhO(-)...H(+)N bond with large proton polarizability is formed between the phenolate and guanidine groups.The polarizable carboxylic acid-guanidine hydrogen bond is broken and the asymmetrical NH...O bond between guanidine and the O atoms of carboxylic acid becomes much stronger.The results obtained with the model are compared with those obtained earlier with bacteriorhodopsin.
View MoreJi'an Hairui Natural Plant Co. Ltd.
Contact:0796-8105528
Address:Meilin industry park, Qingyuan district Ji'an City, Jiangxi Province
Nanjing Yuance Industry&Trade Co., Ltd.
website:http://www.njyuance.cn/
Contact:+86-25-85439097
Address:B1702, Aoti Bldg, No. 130, Aoti Avenue, Nanjing, China
Chengdu Sino-Strong Pharmaceutical Co.,Ltd.
website:http://www.sino-strong.com.cn
Contact:+86-28-82666753
Address:459 West haike road,Cross-straits technological industry park, Wenjiang district,Chengdu, P.R.China
Wuhan Konberd Biotech Co., Ltd.
Contact:+86-27-87205925
Address:NO.666, Gaoxin Road, Eastlake High-tech zone
Nanjing Vincero International Trading Co.,Ltd
Contact:8618936897229
Address:NO.68, ZhuShan Road, JiangNing WanDa Plaza, Building E Room 1703
Doi:10.1002/ejoc.201301681
(2014)Doi:10.1016/j.ejmech.2014.01.033
(2014)Doi:10.1016/S0040-4020(01)85240-6
(1994)Doi:10.1002/chem.201302485
(2013)Doi:10.1039/b310565b
(2003)Doi:10.1021/jm0492397
(2005)
