This enzyme catalyses isomerization between fumarate and maleate. Its active ingredients are chlorpheniramine maleate and codeine phosphate. Codeine is also present in various cough syrups as codeine phosphate including chlorpheniramine maleate. Chlorpheniramine maleate, an H1-blocking antihistamine, relieves histamine-induced allergic edema of respiratory mucosa. Neither brimonidine tartrate nor timolol maleate was mutagenic in in vitro and in vivo studies. Hydrolysis of dimethyl maleate gives maleic acid, or possibly the maleic acid monomethyl ester. Maleic acid esters are also called maleates, for instance dimethyl maleate. It is a combination of dorzolamide hydrochloride and timolol maleate. Dimethyl maleate is used in many organic syntheses as a dienophile for diene synthesis. Dimethyl maleate is an organic compound with the formula CHO. Tyr139 hydrogen bonds with the carboxylate group of the maleate proximal to Cys82. The maleate ion is useful in biochemistry as an inhibitor of transaminase reactions. The standard pharmaceutical preparation, acepromazine maleate, is used in veterinary medicine in dogs and cats. Large Animal Immobilon is a combination of etorphine plus acepromazine maleate. To manufacture the aspartic, an amine is reacted with dialkyl maleate by the Michael reaction.