LAUSR

Plants of the genus Bupleurum L. (Apiaceae) are widely used in traditional Eastern medicine [1]. Their pharmacological activity is associated mainly with the contents of saikosaponins, which possess immunoregulating, antibacterial, and antiviral activity [1, 2]. We began research on the chemical compositions of two lesser studied species B. bicaule Helm (Mukhorshibirsky District, near Kusoty, south slope of Mt. Bays, petrophytous steppe) and B. sibiricum Vest ex Spreng. (Eravninsky District) from populations growing in the Republic of Buryatia. Specimens were collected in July and August 2018. To the best of our knowledge, the fatty-acid compositions have not been published. Lipid fractions were isolated by a modified Bligh and Dyer method [3] and analyzed by GC-MS on an Agilent 6890 GC with a quadrupole mass spectrometer (MSD 5973N) as the detector. The percent composition of mixture constituents was calculated from GC peak areas. Qualitative analysis was based on comparing retention times and total mass spectra of the corresponding pure compounds using NIST14.L library data and Bacterial Acid Methyl Esters (CP Mix, Supelco, Bellefonte, PA, USA) and Fatty Acid Methyl Esters standard mixtures (Supelco 37 comp. FAME Mix 10 mg/mL in CH2Cl2). Lipid contents in aerial parts of B. bicaule and B. sibiricum were 5.36 and 5.46%, respectively; in roots, 8.68 and 11.59%. The main constituents of the lipid fractions agreed for various samples. The dominant acids were palmitic (16:0), oleic (cis18:1n9), and linoleic (18:2n9). The total contents of saturated fatty acids (SFAs) in the analyzed samples were in the range 21.39–42.78%. The greatest content (42.78%) was observed in the aerial part of B. bicaule; the lowest, in roots of B. bicaule and B. sibiricum (21.43 and 21.39%, respectively). The contents of monounsaturated fatty acids (MUFAs) spanned the range 21.50–29.00%. The greatest content (29.00%) occurred for total MUFAs in the aerial part of B. sibiricum; the lowest (21.50%), in the aerial part of B. bicaule. With respect to polyunsaturated fatty acids (PUFAs), the greatest and lowest contents were found in the same species (B. bicaule) in roots (52.63%) and herb (24.50%) (Table 1). Sterols were represented by stigmasterol and β-sitosterol. Total sterols in all samples varied from 0.24 to 0.44%. The greatest contents (0.31%) of stigmasterol occurred in B. sibiricum. Other compounds included an alkyne (6-tridecen-4-yne) (0.52–5.33%) and ketone (10-nonadecanone) (up to 8.74%). Our results were comparable with those published earlier for plants of other species of the genus Bupleurum [4–6] and roots of B. chinense DC. [7, 8].