BIODIVERSITAS ISSN: 1412-033X Volume 22, Number 1, January 2021 E-ISSN: 2085-4722 Pages: 480-490 DOI: 10.13057/biodiv/d220158 Chemical composition and antibacterial activities of Rhus tripartita essential oils from Algeria KHAOULA BENLEMBAREK 1, TAKIA LOGRADA 1 , MESSAOUD RAMDANI 1,  , GILLES FIGUEREDO 2 , PIERRE CHALARD 3 1 Laboratory of Natural Resource Valorization, Faculty of Life and Natural Sciences, Ferhat Abbas University Setif-1. 19000 Setif, Algeria. Tel.: +21-3658 101010,  email: ramdanimessaoud@yahoo.com, ramdanimessaoud@univ-setif.dz 2 LEXVA Analytique. 460 Rue Du Montant, 63110 Beaumont, France 3 Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France Manuscript received: 10 November 2020. Revision accepted: 30 December 2020. Abstract. Benlembarek K, Lograda T, Ramdani M, Figueredo G, Chalard P. 2021. Chemical composition and antibacterial activities of Rhus tripartita essential oils from Algeria. Biodiversitas 22: 480-490. The yield of Rhus tripartita essential oils in Algeria is low with an average of 0.16 ± 0.017. The chemical composition of the oils was determined by GC-GC / MS analysis. Seventy-eight compounds were identified with an average of 92.3 ± 26.4% in the total oil. The α-pinene (58.72 ± 14.45%), Δ3-carene (5.21 ± 6.89%), caryophyllene-Z (4.55 ± 4.68%) and β-pinene (3.07 ± 1 85%) are the major components of the oils of R. tripartita populations. The results reveal a notable difference between the chemical composition of essential oils from male and female populations. The oils of this species are composed of four chemotypes, the Δ3-carene, α-pinene; limonene chemotype characterizes the male populations of Tamanrasset and Boussaada. The α-pinene - Δ3-carene - caryophyllene-Z chemotype characterizes the male populations of M’sila and Mergueb. The female M’sila population is characterized by the α-pinene - Δ3-carene - Δ-cadinene chemotype. The remaining populations show the α- pinene - β-pinene - caryophyllene-Z chemotype. The evaluation of antibacterial activities reveals that Staphylococcus aureus, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa are not sensitive to the essential oils of R. tripartita. In contrast, Enterococcus faecalis is the most sensitive to the oils. Keywords: Algeria, essential oils, chemotypes, antibacterial activities, Rhus tripartita INTRODUCTION The Rhus (Anacardiaceae) consists of approximately 200 species distributed in different temperate zones (Giovanelli et al. 2017). In Algeria, the genus Rhus is represented by three species, Rhus tripartite, R. coriaria, and R. pentaphylla (Quézel and Santa 1962). The Rhus tripartita or Searsia tripartita (Ucria) Moffett is located in arid and semi-arid North Africa (Quézel and Santa 1962) and in the steppes of Western Asia (Idm'hand et al. 2019). Rhus tripartita is widely used in traditional and modern medicine (Lee et al. 2010; Wu et al. 2013). It is used in southern Algeria to treat diabetes, bloating, fever, kidney disease, skin lesions, diarrhea and several gut diseases (Hadjadj et al. 2015). The fruits of Rhus tripartita are eaten fresh or mixed with water, honey, or milk; the leaves are also used as animal feed; the barks and roots are used in crafts to dye leather, wool and silk (Floch 1983; Ben Mahmoud et al. 2015). The products of secondary metabolism of R. tripartita, in particular the phenolic compounds, have anti- carcinogenic, anti-thrombotic and anti-inflammatory (Chung et al. 2010; Ben Barka et al. 2019), anti-nephritic, antimicrobial (Abbassi et al. 2012) activities; antioxidants and preventive properties of breast cancer (Wang et al. 2005; Amin et al. 2007; Shahat et al. 2016). The chemical composition of the genus Rhus is not much studied. The essential oils of R. coriaria from Sicily present cembrene and β-caryophyllene as the majority products of the leaves, while the flowers are characterized by the presence of α-pinene and tridecanoic acid (Ridel et al. 2017); the same results were obtained in Iran by Zhaleh et al. (2018). In a similar study in Turkey, the chemical profile of R. coriaria populations showed that the main components were α-pinene, β-caryophyllene and cembrene (Brunke et al. 1993). Palestinian, Jordanian, and Egyptian sumac (R. coriaria) are characterized by α-pinene, naphthalene and cymene-O, respectively (Farag et al. 2018). Work on the chemical composition of the leaves of R. typhina has shown that monoterpenes are in the majority (Bestmann et al. 1988). The analysis of essential oils from the leaves and flowers of R. mysorensis allowed the estimation of the abundance of α-pinene, limonene, sabinene and β-eudesmol (Srivastava et al. 2005). The ethanolic extracts, from the aerial parts of R. tripartita from the Bechar region (Algeria), showed a weak antibacterial activity against Staphylococcus aureus, Escherichia coli, Enterobacter cloacae and Pseudomonas aeruginosa (Bereksi et al. 2018). While the chloroform extracts from Tunisian populations presented a strong antibacterial activity against S. aureus and strong antifungal activity against the yeast Candida albicans (Abbasi and Hani 2011). The R. tripartita leaves in Libya showed, that both ethanolic extracts and chloroformic solvents, have a low inhibitory effect against E. coli and P. aeruginosa (Habibi et al. 2015). On the other hand, the studies by Tlili et al.