No abstract

In order to continue our previous studies concerning Geranium pyrenaicum Burm. (Geraniaceae), we have performed spectrophotometric determinations and a HPLC study of some polyphenols. We have analyzed the dried Geranii pyrenaici herba (harvested from Cluj-Napoca, district of Cluj, Romania). We have established the content in flavonoids (0.316%), phenolic acids (0.099%), tannins (5.295%), and anthocyanins (12.030 mg/100 g vegetal product). We have identified and measured by HPLC the following compounds: hyperoside (21.61 µg/100 mg), ellagic acid (1810.44 µg/100 mg), isoquercitrine (11.197 µg/100 mg), and caftaric acid (76.83 µg/100 mg). We have also analyzed by HPLC a hydrolyzed sample of the same drug in which we have identified and measured: ellagic acid (4139.33 µg/100 mg), quercetol (29.65 µg/100 mg), kaempherol (41.48 µg/100 mg), and caftaric acid (20.721 µg/100 mg).Species of Geranium have been used for a long time in folk medicine for different actions, including wound healing, diarrhea, ulcer healing, and antibacterial properties [1-3]. These actions are due to the various contents of polyphenolic compounds. Studies have been conducted by researchers from different countries all over the world in order to study these compounds [4][5][6][7][8][9].We have initiated a comparative phytochemical study of some Geranium species from Romania using methods based on spectrophotometry, identity reactions, and HPLC [10-12]. We continue our work by analyzing some polyphenols from Geranium pyrenaicum Burm., using spectrophotometric techniques and an original HPLC method developed in 2003 by a group of young researchers from the University of Medicine and Pharmacy of Cluj-Napoca [13]. This method is of particular interest when the amounts of polyphenols in the plant are too small to allow investigation by TLC methods. It also allows measuring the amount for every identified active principle, while the quantitative spectrophotometric methods that we have used before do not allow measuring each particular polyphenolic compound.The results of the quantitative spectrophotometric determinations are: flavonoids (0.316%), phenolic compounds (0.099%), tannins (5.295%), anthocyanins (12.030 mg/100g dried product).From these quantitative determinations, the tannins seem to be the main group of active principles, in accordance with previous data cited in the international literature.We have identified and measured by HPLC six polyphenolic compounds in Geranii pyrenaici herba, working in the conditions described before: hyperoside, ellagic acid, isoquercitrine, caftaric acid, quercetol, and kaempherol. Good linearity of the calibration curve for a five-point plot was established in the 0.5-50 µg/mL range for all identified compounds. We present the concentrations (µg polyphenolic compound/100 mg dried herba) for these six compounds (Table 1). We also present the HPLC chromatogram for Geranii pyrenaici herba samples, before hydrolysis (Fig. 1) and after hydrolysis (Fig. 2).