Essential oil of Galium verum L. from Iran

The chemical composition of the essential oil obtained from aerial parts of Galium verum L. (Rubiaceae) from Iran was examined by a combination of GC and GC/MS. The oil isolated by hydro-distillation using a Clevenger-type apparatus. Air-dried aerial parts of Galium verum (80 g) which were collected from Bomehen in Tehran province at full flowering stage on May 2003, were subjected to hydro-distillation for 3 h using a Clevenger-type apparatus to produce oil in 1.3% (w/w) yield. The oil was dried over anhydrous sodium sulphate and stored under nitrogen in a sealed vial till analysis. The oil was analyzed by a combination of GC (shimadzu GC-9A) and GC/MS (Varian 3400, Saturn II). The oil isolated by hydro-distillation from the aerial parts of Galium verum was obtained with a yield of 1.3% (w/w), based on the dry weight. Twenty-three components were identified in the essential oil of Galium verum representing to more than 93% of the oil, the major components of which were found to be ?-caryophyllane (26%), caryophyllene oxide (16.2%), and Germacrene D (11.2%). The qualitative composition and quantitative content of polyphenol components of five galium species of Galium has been reported previously, these species have their highest content of flavonoides and tanning agents at the start of growth. The species contain carbohydrates and amino acids. A literature search did not reveal any reference to previous work on the essential oil of Galium verum.