Phenolic profiles, antimicrobial and antioxidant activity of the various extracts of Crocus species in Anatolia

Abstract

The phenolic profile and quantitative composition of methanol extracts of Crocus baytopiorum which was endemic species in Denizli, Turkey was detected by high performance liquid chromatography (HPLC-DAD). The HPLC analysis of phenolic compounds in methanol extract of C. baytopiorum showed that p-Coumaric acid, apigenin-glucoside, rosmarinic acid, quercetin and kampferol were present. Also, the methanol, ethyl acetate and hexane extracts from Crocus biflorus, C. baytopiorum and Crocus flavus subp. dissectus were investigated for their in vitro antimicrobial and antioxidant activities in the present study. Ethyl acetate and methanol extracts have demonstrated significant antimicrobial activities against tested micro organisms Escherichia coli ATCC 35218, Pseudomonas aeruginosa NRRL B-23, Klebsiella pneumoniae ATCC 27736, Yersinia enterecolitica RSKK 1501, Proteus vulgaris RSKK 96026, Bacillus cereus RSKK 863, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Micrococcus luteus NRRL B-4375 and Candida albicans (clinical isolate). The methanol extract of C. flavus subsp. dissectus had maximum activities on Yersinia enterocolitica RSKK 1501. Minimum inhibition concentrations of plant extracts have investigated on Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633 and Bacillus cereus RSKK 863. The Minimum inhibition concentration (MIC) of samples ranged from 0.10 to 20.48 mg/ml. In terms of radical scavenging activity and antioxidant activity, in the concentration of 2 mg/ml of methanol extract of C. flavus (92.67 and 89.32% respectively) displayed inhibition equal to in the concentration of 0.8 mg/ml butylated hydroxytoluene (BHA) used as standard antioxidant (91.45 and 89.78%, respectively). Positive correlations were found between total phenolic content in the Crocus extracts and their antioxidant activities. Thus, it is envisaged that Crocus species may have potential for acting as natural antioxidants.