Chemical Variability of the Berry Essential Oil of Two Subspecies of Juniperus Oxycedrus L. from Northwestern Algeria.

The chemical composition of 33 oil samples isolated from the berries of individual trees of two subspecies of Juniperus oxycedrus L., collected in four locations in Tlemcen and Aïn Temouchent provinces, was investigated by GC-FID, GC/MS and 13CNMR. In total, 83 compounds were identified, accounting for 85.9 % to 98.6 % of the total composition. Yields ranged between 0.02 and 0.40 % (w/w). All compositions were submitted to statistical analysis. Combination of hierarchical clustering dendrogram and principal component analysis suggested the existence of two groups, the second group being sub-divided into two sub-groups. Groups and sub-groups were distinguished with respect to their contents of α-pinene, germacrene D, myrcene and, to a lesser extent, of manoyl oxide. The chemical composition of the oils belonging to subsp. oxycedrus was largely dominated by monoterpenes. α-Pinene (23.7-63.2 %) and germacrene D (4.5-25.4 %) were the major components, followed by myrcene (3.1-16.7 %). Conversely, samples oils of subsp. macrocarpa were largely dominated by germacrene D (4.4-30.0 %), followed by a lower content of α-pinene (10.0-24.3 %) and myrcene (1.0-4.3 %) and a significant content of manoyl oxide (4.3-9.9 %).

Composition, Chemical Variability and Biological Activity of Cymbopogon schoenanthus Essential Oil from Central Algeria.

Cymbopogon schoenanthus (L.) Spreng. (Poaceae) is an aromatic plant whose aerial parts and rhizome produced an essential oil with pleasant odor. A chemical variability has been observed depending of the countries where the plant grows wild, including Algeria. The chemical compositions of 24 oil samples isolated from plants harvested in Central Algeria have been investigated, to evidence homogeneity or chemical variability within a given area of harvest. Twenty of these were dominated by cis- and trans-p-menth-2-en-1-ols (22.6 %±3.6 and 14.3 %±1.7, resp.) beside four atypical compositions. Otherwise, aerial parts and rhizomes produced similar essential oils. Lastly, a fair antimicrobial activity was measured against Staphylococcus aureus strain, while the antioxidant potential was low.

Biological Activities and Chemical Composition of Santolina africana Jord. et Fourr. Aerial Part Essential Oil from Algeria: Occurrence of Polyacetylene Derivatives.

The chemical composition of 18 oil samples of Santolina africana isolated from aerial parts at full flowering, collected in three locations in eastern Algeria was determined by GC(RI), GC/MS and 13C-NMR analysis. The major components were: germacrene D, myrcene, spathulenol, α-bisabolol, ß-pinene, 1,8-cineole, cis-chrysanthenol, capillene, santolina alcohol, camphor, terpinen-4-ol and lyratol. The chemical composition appeared homogeneous and characterized by the occurrence of four derivatives which exhibited a conjugated alkene dialkyne moiety. They were identified for the first time in an essential oil from S. africana. The collective oil sample exhibited moderate antimicrobial and antioxidant activities whereas the anti-inflammatory activity presented a real potential. IC50 value of Santolina africana essential oil (0.065 ± 0.004 mg/mL) is 5-fold higher than IC50 value of NDGA used as positive control.

In silico study the inhibition of angiotensin converting enzyme 2 receptor of COVID-19 by Ammoides verticillata components harvested from Western Algeria.

The objective of this present study is to focus on the in silico study to screen for an alternative drug that can block the activity of the angiotensin converting enzyme 2 (ACE2) as a receptor for SARS-CoV-2, potential therapeutic target of the COVID-19 virus using natural compounds (Isothymol, Thymol, Limonene, P-cymene and γ-terpinene) derived from the essential oil of the antiviral and antimicrobial plant Ammoides verticillata (Desf.) Briq. which is located in the occidental Algeria areas. This study reveals that Isothymol, a major component of this plant, gives the best docking scores, compared to, the co-crystallized inhibitor ß-D-mannose of the enzyme ACE2, to Captropil drug as good ACE2 inhibitor and to Chloroquine antiviral drug also involved in other mechanisms as inhibition of ACE2 cellular receptor. In silico (ADME), drug-likeness, PASS & P450 site of metabolism prediction, pharmacophore Mapper showed that the compound Isothymol has given a good tests results compared to the ß-D-mannose co-crystallized inhibitor, to Captopril and Chloroquine drugs. Also the other natural compounds gave good results. The Molecular Dynamics Simulation study showed good result for the Isotymol- ACE2 docked complex. This study revealed for the first time that Isothymol is a functional inhibitor of angiotensin converting enzyme 2 activity and the components of essential oils Ammoides verticillata can be used as potential inhibitors to the ACE2 receptor of SARS-CoV-2.Communicated by Ramaswamy H. Sarma.