Biomaterial Database

Aquo-pentamine Co(III) complexes as models for carbonic anhydrase. 1984

S K Mohapatra, and K S Prakash, and U L Prasana

The hydrolysis of 4-nitrophenyl acetate by metal complexes Co(en)2(imH)H2O3+, Co(en)2(bzmH)H2O3+, and Co(en)2(imCH3)H2O3+ (imH = imidazole, bzmH = benzimodazole, imCH3 = methyl imidazole) has been investigated in the pH range 5.4-8.9. The small difference in nucleophilic reactivity in the pH range 5.4-6.7 is assumed to be due to hydrogen bonding abilities of the imidazole and substituted imidazole ligands and small pKa differences (k2(imH) = 2.2 X 10(-2) M-1 sec-1, k2(bzmH) = 5.68 X 10(-2) M-1 sec-1, k2(imCH3) = 1.35 X 10(-2) M-1 sec-1, 40 degrees C, 1 = 0.3 NaClO4, pKa(imH) = 6.2, pKa(imCH3) = 6.2 and pKa(bzmH) = 5.9). In the pH range 7.8-8.9, the differences in nucleophilic reactivity (k3(imH) = 85.5 X 10(-2) M-1 sec-1, k3(bzmH) = 33.4 X 10(-2) M-1 sec-1, 40 degrees C, I = 0.3 NaClO4) are reconciled with a significant steric factor outweighing the acidity of the benzimidazole complex. In the pH region 6.7-7.7, the deviation from linearity is presumably due to both hydroxo and imido ligands functioning as nucleophiles, the latter being about 40 times stronger than the former.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D009596	Nitrophenols	PHENOLS carrying nitro group substituents.	Nitrophenol
D002256	Carbonic Anhydrases	A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of CARBON DIOXIDE from the tissues to the LUNG. EC 4.2.1.1.	Carbonate Dehydratase,Carbonic Anhydrase,Anhydrases, Carbonic,Dehydratase, Carbonate
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000499	Allylamine	Possesses an unusual and selective cytotoxicity for VASCULAR SMOOTH MUSCLE cells in dogs and rats. Useful for experiments dealing with arterial injury, myocardial fibrosis or cardiac decompensation.	3-Aminopropylene,3 Aminopropylene
D000588	Amines	A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Amine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.