Evaluation of antibacterial, antioxidant activities and secondary metabolites profile of orchids with different dried methods

The Central Black Sea region is a very dense region in terms of orchid diversity. As a consequence of the floral studies, 32 species of salep orchids were identified in the Central Black Sea Region. The aim of this current study was to identify the secondary metabolite profiles of leaves and tubers of two orchid species (Anacamptis palustris and Ophrys apifera) with different drying methods by HPLC analysis and to determine their antibacterial and antioxidant activities. For this purpose, different drying methods were applied to the roots and leaves of these two species. The species were dried by 3 different techniques: shade, lyophilizer and oven. After the aqueous extracts were obtained, their antibacterial and antioxidant activities were tested and HPLC analysis was completed. The data obtained from aqueous extracts as a result of drying techniques were compared with the data obtained from fresh plant aqueous extracts. Antibacterial properties were tested against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 bacteria. No antibacterial activity was found in the study. Antioxidant properties were tested via DPPH and FRAP assays. As a result of DPPH free radical scavenging assay, the highest antioxidant efficiency in A. palustris was observed in leaves dried in lyophilizer (76.53%), in the shade (62.13%) and in the oven (54.12%), respectively. Nine different phenolic compounds were found in aqueous extracts of these species. Epicatechin, Gallic Acid, Rutin, Syringic Acid phenolic compounds were observed the most in HPLC analysis. The results of current study suggest that these extracts have antioxidant and phenolic contents and should be investigated in more comprehensive studies.