Determination of Colchicine and phytochemical components in some colchicum species naturally distributed in Turkey

Türkiye, due to its geographical location and climate, is quite rich in plant genetic diversity. Türkiye's flora contains approximately 12,000 naturally occurring plant species. A significant portion of this diversity consists of geophytes (plants with many bulbs, tubers, and rhizomes), which are of economic importance to the ornamental plant sector. Bulbous plants have an aesthetic and pleasing appearance. Natural flower bulbs account for approximately 7% of Türkiye's ornamental plant export values. The genus Colchicum, commonly known as bitter crocus or autumn crocus, belongs to the Colchicaceae family and is one of the important bulbous plants naturally distributed in Türkiye. In addition to their aesthetic appearance, Colchicum species also hold a significant place in pharmacology due to their secondary metabolites such as colchicinoids. In this study, Colchicum cilicicum (Boiss.) Dammer., Colchicum minutum K.M. Perss., Colchicum szovitsii Fisch. C.A.Mey. subsp. szovitsii, Colchicum baytopiorum C.D. Brickell species were investigated for their antimicrobial activity using the diffusion method in extracts prepared with ethanol and methanol from the underground parts. Additionally, the aim was to determine the antioxidant activities and total phenolic contents of the obtained ethanolic and methanol extracts using the DPPH method. Extraction processes were conducted under 15 different conditions using onion explants taken from the underground parts of each species using two different solvents (ethanol and methanol) at three different combinations of solvent concentration (20%, 50%, and 80%), temperature (30-45-60°C), and time (60-70-80 min) in a factorial, randomized complete block design to determine the conditions that would yield the highest colchicine. In this process, optimized using the Box–Behnken Method Design, Antioxidant activities, total phenolic content, total flavonoid content, and colchicine values of extracts prepared with ethanol and methanol were obtained using DPPH and FRAP methods, and extraction conditions were determined and examined. In terms of colchicine content, the highest amount was detected in C. minutum (0.145%) in ethanol extraction, followed by C. szovitsii (0.044%), C. cilicicum (0.036%), and C. baytopiorum (0.018%). In methanol extraction, the highest amount of colchicine was detected in C. minutum (0.273%), while the lowest was detected in C. szovitsii (0.072%). Keywords: Colchicum spp, Colchicine, Geophyte, Extraction