Chemical Composition of the Essential Oil of Neem (Azadirachta indica A. Juss. ) Seeds Harvested in Senegal

Abstract

Objective: To make better understanding of the neem seed composition (Azadirachta indica A. Juss.) particularly in Senegal by the extraction, the proportioning and the determination of the composition of its essential oil. Methods:The extraction of essential oil from neem seeds is carried out by hydro-distillation. The Gas Chromatography (GC) and Mass Spectrometry (MS) were used for analysis and identification of components. Findings: The yield of essential oil from dry neem seeds (95.7% dry matter) is 0.076%. The major compounds identified are 5,6-dihydro-2,4,6-triethyl-(4H) 1-3,5-dithiazine (39.1%), cis 1,2,4-Trithiolane, 3, 5-diethyl (7.9%), 1-H-indole 2,3-dione (7.9%), trans 1,2,4-Trithiolane, 3,5-diethyl (6.2%), and ethyl thioisobutyrate (4%). The classification of compounds reveals that the essential oil of neem seeds is composed of sulfur and nitrogen compounds (40.1%), sulfur compounds (25.3%), and nitrogen compounds (15.1%), sesquiterpenes (7.4%), Fatty Acid Esters (FAE) (1.5%) and hydrocarbons (0.4%). This composition reveals that neem essential oil is mainly composed of non-terpene compounds. Novelty: The method of analysis by GC-MS although being the most widely implemented in the quantification and identification of volatile compounds is not applied in the case of neem seeds of African origin.

Chemical Composition and Geographic Variation of Cold Pressed Balanites aegyptiaca Kernel Oil

“…Notably, β-sitosterol dominates across all analyzed samples, with concentrations ranging from 570 to 1295 mg/kg oil, constituting 58% to 74% of the total phytosterol content in BKO. The results align with comparative studies in Senegal, where the reported total phytosterol content is 2110 mg/kg oil, and Nigeria, where it is 1102 mg/kg, emphasizing also the prevalence of β-sitosterol in BKO [24,46]. However, these were the only studies reporting a phytosterol composition of BKO.…”

“…The FA composition of BKO has already been described partly in the literature with linoleic, oleic, palmitic, and stearic acids identified as the main FA. However, there are conflicting results regarding the predominant FA, with some studies agreeing with the present findings and indicating linoleic acid as the major FA, followed by oleic acid [3,8,14,[21][22][23][24]. In contrast, other studies claimed that oleic acid is the most important FA in BKO, followed by linoleic acid [10][11][12]25].…”

“…In terms of predominance according to the carbon number in BKO TAG, the predominant ones had a carbon number of 54 (LiLiOl, OlLiOl, StLiOl, LiLiLi, OlOlOl, StOlOl, StOlSt), followed by 52 (PaLiLi, PaLiOl, PaLiSt, PaOlOl), and then 50 (PaLiPa, PaLiPa, PaOlPa). The study described by Diedhiou et al [24] reported only three TAG in BKO (PaPlLi, PaOlLi, and StOlLi). BKO contains the most commonly represented TAG among the various oils reported in the literature.…”

“…Notably, α-tocopherol (αtoc) predominated in all analyzed samples, ranging from 324 to 607 mg/kg, followed by γ-tocopherol (γ-toc) ranging from 120 to 226 mg/kg, both constituting 90% of the total tocochromanol composition. Only two studies have been reported so far on the tocochromanol composition of BKO, indicating total tocochromanol contents of 510 mg/kg for BKO from Senegal [24] and 420 mg/kg for BKO from Sudan [21]. Both studies reported α-toc and γ-toc as the primary tocochromanols in BKO samples.…”

Physicochemical and Biochemical Composition of <i>Balanites aegyptiaca</i> Seed and Seed Oil from Burkina Faso

“…Linoleic acid sounds to be the major fatty acid in B. aegyptiaca seed oil. In fact, in the work of Diedhiou et al [33] linoleic acid was the most predominant (about 37%) in the B. aegyptiaca seed oil. This confirms our results on the importance of linoleic acid in B. aegyptiaca seed oil.…”