Gas Chromatography-Mass Spectrometry Analysis and Antimicrobial and Antioxidant Activities of Some Orchid (Orchidaceae) Species Growing in Turkey

Abstract

Plants are well known throughout the world for their medical activities. The history of orchids used in many different countries around the world probably started with their use for medicinal purposes thanks to their therapeutic properties. The aim of this study, to investigate antioxidant and antimicrobial activity of ethanol extracts of plant and tuber parts of eight different epiphytic orchids from Turkey as well as their chemical composition. The antimicrobial screening of extracts was performed against 8 bacterial and 2 fungal species. To determine general chemical profile of them gas chromatography-mass spectrometry analysis was done. Antioxidative potentials of the species were proved based on 2,2-Diphenyl-1-picrylhydrazyl radical scavenging and ferric reducing antioxidant power assays. All tested extracts prepared from orchid species especially showed intermediate inhibition activity against Proteus vulgaris and Yersina enterocolitica. The Gas Chromatography and Mass Spectrometry results showed that the phytoconstituent contents of the samples were high. In the case of all extracts, more than 100 compounds were identified. But, distinctive differences in composition between each orchid species were not observed. A good correlation degree between the results of the two antioxidant tests was calculated. These well -determined antioxidant activityvalues can be attributed to the total phenolic content in terms of gallic acid equivalent, determined in a relatively high range (491.41-14082.94 mg GAE/g sample). These data show that different parts of the orchid samples obtained from Turkey with a past history have remarkable antimicrobial and antioxidant activity.