Essential oil of Indian propolis: chemical composition and repellency against the honeybee Apis florea.

Hitherto unknown biological properties and the chemical composition of the essential oil isolated from propolis of Indian origin were established. GC/MS Analysis of the essential oil revealed the presence of 32 constituents, of which ten were major compounds, nine had intermediate contents, and 13 were minor compounds. With the exception of six minor constituents, that could not be identified, their identification was based on the comparison of their mass spectra and Kovats retention indices with those listed in the NIST and Wiley mass spectral libraries. Their structural assignment was confirmed by GC/MS co-injection of the essential oil with authentic compounds. Quantification of the components was done by GC-FID analyses. Moreover, the essential oil was shown to possess repellent activity against the honeybee Apis florea. The activity was found to be dose dependent. The average repellency (ΔR) increased with increasing essential-oil concentration up to 24 μg/ml and remained constant for the formulation with the higher concentration. These findings established the chemical constitution of the essential oil and might be useful to beekeepers for the improvement of the bee management.