Synthesis, acetylcholinesterase, butyrylcholinesterase and tyrosinase ınhibition, and antioxidant studies of 2-[2-(substituted-benzyl)-4(7)-phenyl-1H-benzimidazol-1-yl]acetohydrazides and methyl 2-[2-(substituted-benzyl)-4(7)-phenyl-1H-benzimidazol-1-yl]acetates