1, 8- Cineole Extracted from Eucalypt Ecotypes’ Leaves: I. A Novel Mi-2 crowave-Assisted Steam Distillation Method (MASD); Its Uploading 3 into Natural Polymeric Encapsules for Pest Control

This research explores the potential of green encapsules uploaded with eucalypt essential oil (EEO) 9 in enhancing their functionality and application in pest control, focusing on suitable ecotype selec-10 tion and optimizing extraction processes. Eucalypt hybrids’ leaves were collected from three differ-11 ent sites and the EEOs were extracted using microwave-assisted steam distillation (MASD) and elec-12 tric steam distillation (ESD) techniques. The physical and chemical properties of the EEO were de-13 termined. The identification of volatile chemical ingredients in the resulting EEO was conducted 14 using GC/MS after saponification and methylation procedures and were compared to those ob-15 tained from Eucalyptus globulus Labill, the ideal species containing the 1, 8-cineol, the principal com-16 pound in its essential oil. The 1,8-cineole was found to be the major chemical constituent of the EEO 17 interfered with other minor components such as 3-carene, α-pinene, α-myrcene, D-limonene, and 18 α-terpinene. Eucalypt ecotypes grown at Hada Al-Sham village had the highest cineole content 19 (59.29%) among the other sites studied. Compared to the ESD, the essential oils extracted by the 20 MASD showed much promise, defining it as potential industrial essential oil extraction. Microcap-21 sules of either guar gum crosslinked by borax or sodium alginate crosslinked by calcium chloride 22 were fabricated. Moreover, bioassay screening of the polymeric encapsules uploaded with 1, 8-cin-23 eole were evaluated against termite infection. They were found to be versatile tools with a wide 24 range of applications with the superior for the alginate encapsules. Furthermore, regardless the en-25 capsule type and the exposure duration, the mortality (%) of the insects were exceeded significantly 26 for the high cineol concentrations comparing to the lower ones for both ABE and GGBE. The higher 27 the cineol concentrations, the higher the mortality percent of the termites This finding can be at-28 tributed to the rapid toxic effect of the cineol compound at the higher concentrations.