543.51:582.972.3 and B. A. VinogradovThe genus Galium L. (Rubiaceae Juss.) is represented in the flora of Ukraine by greater than 50 species. We investigated earlier the essential oil constituents of G. verum L., G. hercynicum Weigel., and G. humifusum M. Bieb. [1,2]. In continuation of research on plants of this genus, we studied the essential oil composition of G. salicifolium Klokov flowers and herb. Specimens were collected in the vicinity of Sokolovo, Kharkiv Oblast, in June 2010 (herbarium specimen No. 10/10 is preserved in the Herbarium at the Department of Pharmacognosy, NPU).Steam distillation with subsequent treatment of the distillate with high-purity pentane was used to obtain the essential oil. This isolated the essential oil contained in the plant in minor or trace quantities [3]. The constituent composition of the essential oil from flowers and herb was established on an Agilent Technology 6890N chromatograph with a 5973N massspectrometric detector. The analytical conditions were quartz chromatography column, HP-5MS capillary; column length 30 m; inner diameter 0.25 mm; stationary phase diphenyl (5%)-dimethylsiloxane (95%) copolymer, stationary phase film thickness 0.25 Pm; He carrier gas, carrier-gas flow rate 1 mL/min; sample volume 2 PL; sample injection in splitless mode (without flow division); sample injection rate 1.2 mL/min for 0.2 min. The thermostat temperature was 50°C with programming at 4°C/min to 220°C. The detector and vaporizer temperatures were 250°C. Mass spectra were recorded in an HP MSD 5971 quadrupole mass spectrometer with electron-impact ionization at ionizing electron energy 70 eV. Data were collected at 1.9 scans/s in the range 30-650 amu (Agilent 5973N). Compounds were identified by comparison with mass spectra of compounds in the Wiley 275 and NIST98 mass spectra libraries and with mass spectra of standard samples.We found qualitative and quantitative differences for the constituent compositions of essential oils from herb and flowers (Table 1). A total of 63 compounds were identified in G. salicifolium flowers. They included 18 monoterpenoids, 4 sesquiterpenoids, 2 diterpenoids, 1 triterpenoid, 3 aromatic compounds, and 35 hydrocarbons and their derivatives. The monoterpenoids comprised the nor-terpenoid D-isophorone; acyclic trans-linalool oxide, cis-linalool oxide, linalool, nerol, geraniol, and geranylacetone; monocyclic D-phellandren-8-ol, E-phellandren-8-ol, D-terpineol, terpinen-4-ol, and eucarvone; bicyclic chrysanthenone, myrtenol, and trans-verbenol; bornylacetate; monocyclic aromatic p-cymen-8-ol; and the monoterpene oxide syringyl alcohol B. The sesquiterpenoids were represented by the nor-terpenoid and E-ionone; acyclic D-farnesene and hexahydrofarnesylacetone. Diterpenoids included phytol and geranyl-linalool. The triterpene squalene was present. Aromatic and phenolic compounds ranged from benzaldehyde and phenylacetaldehyde to 2-methoxy-4-vinylphenol.The dominant constituents in the flowers were (%) trans-verbenol (19.49), E-phellandren-8-ol (14.23), D-phe...