Fifteen novel aryl, substituted aryl and heteroaryl γ‐hydroxy‐ (2a–e), γ‐methoxyimino‐ (3a–e), and γ‐benzyloxyimino‐ (4a–e) butyric acid methyl esters were investigated for their enzyme inhibition, and the synthesis of 10 compounds (3a–e, 4a–e) is given in this study. The other five compounds (2a–e) were synthesized before in another study. Compounds 3a–e and 4a–e were synthesized in this work as original compounds and characterized by ¹H and ¹³C NMR, IR, mass, and elemental analyses. Their (E/Z)‐isomerisation ratios were analyzed by ¹H and ¹³C NMR. All of them are of pure (E)‐configuration. Due to the literature survey, the elastase inhibition activity was not studied for these compounds. Elastase inhibition ability was investigated in this work for five γ‐hydroxy‐ (2a–e), five γ‐methoxy‐ (3a–e), and five γ‐benzyloxyimino‐ (4a–e) butyric acid methyl esters. All these 15 compounds showed elastase inhibition activity. Compound 2b was the best one and exhibited a better activity than the standard ursolic acid whereas compound 2a worked like the standard. All these compounds can be novel elastase inhibitor agents in the pharmaceutical and cosmetic industries.