Comparative study on the antioxidant and biological activities of carvacrol, thymol, and eugenol derivatives.
Four derivatives of thymol, carvacrol, and eugenol were synthesized: 4-(hydroxymethyl)-5-isopropyl-2-methylphenol, 4,4'-methylenebis(5-isopropyl-2-methyl)phenol, 4-allyl-6-(hydroxymethyl)-2-methoxyphenol, and 4-(hydroxymethyl)-2-isopropyl-5-methylphenol. The obtained derivatives showed remarkably better antioxidative properties according to 1,1-diphenyl-2-picrylhydrazyl assay (50% inhibitory concentrations = 4-156 microg/mL) and Rancimat assay (protection factors = 1.55-5.84) when compared with parent compounds and values similar to or better than those of butylated hydroxytoluene and vitamin C. At concentrations of 10 mM carvacrol derivatives had no toxic effect on viability of Escherichia coli K-12 (determined by minimum inhibitory concentrations). Other phenol derivatives showed reduced cytotoxic effect on E. coli K-12 at concentrations of 2-5 mM on the basis of 50% lethal dose measurements. In comparison with the parent compounds, phenol derivatives showed reduced cytotoxic effect for Saccharomyces cerevisiae cells (determined by yeast colony reduction). On the other hand, the majority of synthesized compounds had dose-dependent antiproliferative effects on human uterine carcinoma cells (HeLa), which makes them potentially interesting for the adjuvant experimental cancer treatments. The 4,4'-methylenebis(5-isopropyl-2-methyl)phenol derivative of carvacrol showed lower inhibiting capacity also for the HeLa cells, which makes this particular derivative attractive as an efficient antioxidant with negligible cytotoxic effects.
Mastelić
Josip
J
Department of Organic Chemistry, Faculty of Chemistry and Technology, University of Split, Split, Croatia. josip.mastelic@ktf-split.hr
Jerković
Igor
I
Blazević
Ivica
I
Poljak-Blazi
Marija
M
Borović
Suzana
S
Ivancić-Baće
Ivana
I
Smrecki
Vilko
V
Zarković
Neven
N
Brcić-Kostic
Krunoslav
K
Vikić-Topić
Drazen
D
Müller
Norbert
N
D000890:Anti-Infective Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D000081007:Cymenes; D048168:Escherichia coli K12 / Q000187:drug effects; D005054:Eugenol / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D039821:Monoterpenes / Q000494:pharmacology*; D013943:Thymol / Q000494:pharmacology*
D000890:Anti-Infective Agents; D000935:Antifungal Agents; D000975:Antioxidants; D000081007:Cymenes; D039821:Monoterpenes; D013943:Thymol; D005054:Eugenol; C073316:carvacrol