The amount of secondary metabolites in cultivated Gentiana lutea L

The roots of Gentiana lutea are the officinal drug in European pharmacopoeia. However, recent investigation suggested that also the aerial parts of this plant could be useful as medicinal material [1,2]. Samples of leaves and roots of G.lutea were collected in June 2006 from three experimental plantations (two, three and five years old) on mountain Tara (1000m). Second sampling was conducted by the end of vegetation, in October 2006. Plantations were established via nursery plants, produced from the seeds collected from nature (mountain Suvobor, Serbia). In all plantations the same agrotechnique measures were performed. Type of soil was Acid Brown, pH 5.5, clay content 7%, humus content 5%. Air-dried powdered plant material was extracted with methanol in ultrasonic bath for 30min. Mangiferin (MG), isogentisin (IG) and gentiopicrin (GP) were isolated according to a previously published procedure [3]. Quantification of MG, IG and GP was performed using HPLC and calculated from calibration curves. The amounts of secondary metabolites in leaves and roots varied during the age of plantation, as well as during the vegetation period. The production of GP and MG in leaves and GP in roots is higher in younger plants (two-years old) than in five-years-old plants. Moreover, the seasonal variation in the content of these metabolites is recorded, i.e. their amounts decreased from June to October. IG showed different dynamic of accumulation. With the exception of two-years-old plants, in all samples collected in June this compound was found in traces, while its content increased by the end of vegetation period. Also, the amount of IG increased with cultivation period, being 0.21 and 2.9mg/g of dry weight in roots of two-years-old and five-years-old plants, respectively, and 1.95 and 4.84mg/g dry weight in leaves of two-years-old and five-years-old plants, respectively.

References: [1] Nikolaev, S.M. et al. (1987) Izv. Sib. Otd. Akad. Nauk URSS Ser. Biol. Nauk 0: 3. [2] Menković, N. et al. (2000) Planta Med. 66: 178. [3] Menković, N (1997) Ph D. Thesis, Faculty of Pharmacy, Belgrade.