GC-MS Analysis of Propolis Samples from three Different Regions of Palestine

Abstract

Bees make propolis from the resin collected from trees buds. The resin chewed and mixed with saliva and the mixture (propolis) then used to close holes in the hive. It is also used as disinfectant that prevent viral and bacterial infections of the bee. Propolis organic compounds proved to have biological and pharmacological characteristics, such as antibacterial, anticancer, and anti-inflammatory activities, however, its popularity and value are just recently get noticed as one of the valuable sources for therapeutic compounds that is recently recognized by many researchers. The aim of the current study was to identify the various chemical compounds in propolis samples collected from three different regions of the Palestine and to shed the light on some of these chemical compounds and their pharmaceutical potential. One sample of Propolis was collected from each of three different regions; Jericho, Hebron and Nablus districts during 2018-2019. Ethanol extracts of propolis (EEP) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-MS). Thirty-three, 27 and 17 different chemical compounds were found in tested samples from Hebron, Jericho and Nablus governorates, respectively. Samples from Nablus, Jericho and Hebron regions showed similar chemical composition for only four compounds including: ascorbic acid, glycerol, oleic acid and pimaric acid. GC-MS chromatograms showed that the total time of each sample spent on the column after injection was 141, 122, 104 minutes in Nablus, Jericho and Hebron, respectively. The percentage of area under the peak (area) of the identified compounds in samples collected from Nablus region was measured where; 6 of these compounds were occupied an area more than 5%. The percentage of area for each of the compounds identified in Jericho samples was also calculated. Eight of these compounds were with a percentage area more than 5%. The percentage of area for each of the compounds identified in Hebron samples was calculated, seven of these compounds were with an area more than 5%. Pimaric acid area in the chromatogram was the largest in samples collected from Nablus region, reflecting a significant amount of this compound, compared to the area size of propanoic, oleic and pimaric acid. Area size of this compound was also found to be the largest in all tested samples collected from the three regions. To the best of our knowledge this is the first study of its kind that search for the propolis composition in Palestine with the hope to find and identify any promising components of pharmaceutical potential.