Antioxidant and cytotoxic activities of naphthalene derivatives from Diospyros kaki

Abstract

4,8-Dihydroxy-5-methoxy-2-naphthaldehyde (Compound I) was isolated from blackened heartwood of Diospyros kaki and was methylated with diazomethane. Antioxidant and cytotoxic activities of Compound I and two methylated derivatives [4-hydroxy-5,8-dimethoxy-2-(2oxopropyl)-naphthalene (D-1) and 2-glycidyl-4-hydroxy-5,8-dimethoxy naphthalene (D-2)] were evaluated. Compound I showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and reducing power than D-1 and D-2. However, D-1 and D-2 exhibited slightly stronger 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) + (ABTS + ) radical scavenging activity than Compound I. Compound I also exhibited stronger cytotoxic activity than D-1 and D-2 against the growth of HT-29 colon cancer cells. The results supported the hypothesis that methylation of naphthalene derivatives slightly increased ABTS + radical scavenging activity, but signifi cantly decreased DPPH radical scavenging activity, reducing power, and cytotoxic activity.

Screening and Evaluation of Antioxidant Activities of Selected Naphthalene Compounds

“…The presence of reductants causes the reduction of the Fe 3+ -ferricyanide complex to the Fe 2+ in conformity with the measurements of the blue-color such as antioxidant substances in the naphthalene derivatives (Matsushita et al 2011). An increase in absorbance of the reaction mixture may indicate an increase in the reducing capacity due to an increase in the formation of the complex, Fe 4 [Fe(CN − ) 6 ] 3 ).…”

Untitled

“…The presence of reductants causes the reduction of the Fe 3+ -ferricyanide complex to the Fe 2+ recorded by measuring Perl's Prussian blue at 700 nm. 52 The reducing power abilities of oximes were measured at concentrations (5-100 μM) 35 and compared standards (BHA, BHT, TBHQ, trolox). An increase in absorbance of the reaction mixture may indicate an increase in the reducing capacity due to an increase in the formation of the complex, Fe 4 [Fe(CN − ) 6 ] 3 .…”

Synthesis, characterization, and investigation of some properties of the new symmetrical bisimine Ni(II), Zn(II), and Fe(III) complexes derived from the monoimine ligand

“…Bisimines derived from 2-hydroxy-1-naphthadehyde and their metal complexes are known to have a wide range of biological activity as well as function as fluorescent chemosensors and selective electrodes. [1][2][3][4][5][6][7] The compounds having imine bonds ( C N ) are known by many names such as imines, Schiff bases, azomethines, and salens. Salen-or salophen-type ligands are also called monoimines if they contain a single imine group and bisimines if they contain two imine groups.…”