Our present findings are in agreement with another study by Kubo and coworkers on alkyl protocatechuates [23]. The authors reported that the LOX inhibitory activity increases with increasing lipophilicity arising from longer alkyl chain lengths of their synthesized compounds. The replacement of aliphatic chain by cyclohexyl ring significantly decreased the inhibitory activity. This might be due to the cyclohexyl ring is no longer flat and the bulkier structure make the binding region for the cyclic ring become narrow and thus making the analog incapable of fitting into the active site [24]. In contrast, the replacement of cyclohexyl ring with a longer aromatic ring exhibited better inhibitory activity than tHGA since the aromatic ring is planar enough to fit into the active site. Among the five active compounds, three compounds 3c, 3e and 3g exhibited higher inhibitory activities than tHGA.