Gilles Figueredo

A Study on the Composition of Commercial Vetiveria zizanioides Oils from Different Geographical Origins

Abstract This work reports the chemical composition of essential oils of Vetiveria zizanioïdes (L.) Nash from nine countries: Brazil, China, Haiti, India, Java, Madagascar, Mexico, Reunion and Salvador. Analyses were performed using GC/MS, and about 110 constituents were identified in oils, mainly sesquiterpenes. The characteristic constituents were β-vetispirene (1.6–4.5%), khusimol (3.4–13.7%), vetiselinenol (1.3- 7.8%) and α-vetivone (2.5- 6.3%). No meaningful differences were observed comparing the composition of nine geographical origins. Hierarchical clustering and principal component analysis (PCA) of the compositional data of the oil samples confirm the relative homogeneity of V. zizanioides by the content of major constituents (khusimol, β-vetivenene and β-vetispirene).

Chemical variation of essential oil constituents of Ocimum gratissimum L. from Benin, and impact on antimicrobial properties and toxicity against Artemia salina leach

To determine the period of harvest that optimizes the antimicrobial activities of the essential oil of Ocimum gratissimum L. from Benin, aerial plant parts were collected at two vegetative stages (pre‐ and full‐flowering) and three sampling times (7 am, 1 pm, and 7 pm). Extraction by hydrodistillation yielded between 0.65 and 0.78% of essential oils. Characterization of the oils by GC‐FID and GC/MS analysis revealed the presence of monoterpenes (87.26–93.81%), sesquiterpenes (5.57–11.34%), and aliphatic compounds (0.15–0.18%), with p‐cymene (1; 28.08–53.82%), thymol (2; 3.32–29.13%), γ‐terpinene (3; 1.11–10.91%), α‐thujene (4; 3.37–10.77%), and β‐myrcene (5; 4.24–8.28%) as major components. Two chemotypes were observed, i.e., a p‐cymene/thymol and a p‐cymene chemotype, for plants harvested at 7 am for the former and at 1 pm or 7 pm for the latter, respectively. The oils were fungicidal against Candida albicans, with the sample from full‐flowering plants collected at 7 am being the most active (MIC = 0.06±0.00 mg/ml). The chemical variation of the oils also influenced the antimicrobial effect against Staphylococcus aureus; the most active oil was obtained from plants at the pre‐flowering stage collected at 7 am (MIC=0.24±0.01 mg/ml). Escherichia coli was insensitive to the chemical variation of the oils (MICs of ca. 0.48±0.02 mg/ml for all oils). Moreover, the essential oils showed low toxicity against Artemia salina Leach larvae, with LC50 values in the range of 43–146 μg/ml. This is the first study of the interaction between the daytime of collection and vegetative stage of the plants and the antimicrobial properties and toxicity of the essential oil of O. gratissimum from Benin.

Essential Oil Chemical Composition of Annona muricata L. Leaves from Benin

Abstract Essential oils from leaves of Annona muricata L. were obtained by steam distillation with a very low percentage. Analysis made by GC and GC/MS showed the presence of 80 compounds. The most abundant constituents were β-caryophyllene (13.6%), δ-cadinene (9.1%), epi-α-cadinol (8.4%), α-cadinol (8.3%).

Chemical Composition of Lebanese Rosemary (Rosmarinus officinalis L.) Essential Oil as a Function of the Geographical Region and the Harvest Time

Abstract The essential oils of rosemary (Rosmarinus officinalis L.) from three locations in Lebanon were extracted by steam distillation and their chemical composition was determined by GC/MS. The plants were collected during two years at either flowering stage or after. The oils obtained did not show appreciable differences in their composition in relation to geographical region. The three oil samples were found to be rich in α-pinene (18.8–38.5%) and 1,8-cineole (19.1–25.1%). The Lebanese oils had particularly high levels of α-terpineol (2.9–11.2%) and geraniol (1.8–9.3%). Although the results obtained did not indicate a large variation of oil composition in relation to harvest time (flowering and after flowering), some reproducible differences were noticeable. A parallel study on rosemary leaves and flowers from one of the three locations showed that their oils had the same chemical composition.

Studies of Mediterranean Oregano Populations IX: Chemical Composition of Essential Oils of Seven Species of Oregano of Various Origins

Abstract The essential oils of seven species of oregano (Origanum vulgare L. ssp. gracile (Koch), Origanum acutidens (Hand.-Mazz.) Ietswaart, Origanum hypericifolium O. Schwarz et P.H. Davis, Origanum bargyli Mouterde, Origanum saccatum P.H. Davis, Origanum solymicum P.H. Davis, and Origanum leptocladum Boiss.) were studied by GC and GC/MS. Eighty-five constituents were identified. The discriminant components of these oils were p-cymene, γ-terpinene, cis- and trans-sabinene hydrate, borneol, terpinen-4-ol, α-terpineol, thymol, and carvacrol. Some of the species were similar to those described in the literature, and new chemotypes are reported.

Studies of Mediterranean Oregano Populations. VII: Chemical Composition of Essential Oils of Carvacrol-Rich Oregano of Various Origins

Abstract Six species of oregano were studied: Origanum compactum Benth., O. dictamnus L., O. dubium Boiss., O. minutiforum Schwarz et Davis, O. onites L. and O. vulgare ssp. hirtum Ietswaart. Collected at their natural sites, sown, planted and oils isolated at the CNPPMAI. The oils were analyzed by GC and GC/MS; 118 constituents were identifed. All species presented a carvacrol chemotype (60—90%) accompanied by various chemical forms, such as a thymol-rich type, as in O. dictamnus, O. dubium and O. vulgare ssp. hirtum, in which its levels ranged widely (20—90%), or linalool-rich (27—90%), as in O. onites and O. dubium.

Essential Oil Composition of Vetiveria nigritana from Mali

Abstract An oil was obtained from roots of Vetiveria nigritana (Benth.) Stapf collected in Mali and analyzed by GC and GC/MS. Fifty-four constituents (79.7% of the whole oil) were identifed. Prezizanoic acid (15.0%), preziza-7(15)-en-12-ol (9.5%), cedren-8-en-15-ol (6.2%), preziza-7(15)-en-3α-ol (6.0%) and zizanoic acid (5.9%) were the major components of Vetiveria nigritana oil.

Chemical Composition of the Essential Oil of Xylopia aethiopica (Dunal) A.ch. from Mali

Abstract We analyzed the essential oil of Xylopia aethiopica from dried fruit and the powder obtained from crushed dried fruit using combined GC and GC/MS. The principal constituents identified in the fruit oil were β-pinene (19.1%), γ-terpinene (14.7%), trans-pinocarveol (8.6%) and p-cymene (7.3%). In the oil from the powder die major constituents were β-pinene (9.9%), α-cadinol (6.9%), trans-pinocarveol (4.6%), α-pinene (4.1%) and 1,8-cineole (4.0%).

Study of Essential Oil Composition of Elyonurus hensii Schum from Congo

Abstract Seventy constituents were identified by GC and GC/MS analysis of the oils from the leaves and flower tips, stalks and roots of Elyonurus hensii Schum. The compounds p-cymene, p-mentha-2,8(9)-dien-1-ol, p-mentha-1(7), 8-dien-2-ol, 2-undecanone, 2-tridecanone, intermedeol and aristolone characterize and discriminate the underground and aerial parts of the plant.

Yield and Composition of Essential Oils From Eucalyptus citriodora x Eucalyptus torelliana, a Hybrid Species Growing in Congo-Brazzaville

Abstract Essential oils from leaves of E. citriodora and E. torelliana pure species and E. citriodora x E. torelliana hybrids, obtained by hydrodistillation, were analyzed by GC and GC/MS. Six oil samples of E. citriodora showed two main constituents (citronellal 57.1–75.4% and citronellol 8–11%) out of 64 identified constituents (> 0.1%). Nine oil samples from E. torelliana contained 78 constituents (> 0.1%) with various main constituents: α-pinene (20.3–78.1%), globu- lol (20–26%) and citronellyl acetate (55.5%). Six oil samples of E. citriodora x E. torelliana hybrids were of a citronel- lal/citronellol chemical type (66–76%), like E. citriodora, or α-pinene (24.3–49.5%), or citronellyl acetate (61.4%) chemical type, like E. torelliana.