Pauline Burger

New insights in the chemical composition of benzoin balsams.

Benzoin balsam is an anthropic exudate obtained from the bark of several species of Styrax trees that is mainly used as a perfume fixative as well as a flavouring agent. Benzoe tonkinensis Laos (also commercialized under the denomination Siam benzoin balsam) displaying characteristic vanilla notes and already being largely used to flavour all kinds of edible goods, was intended to be proposed by Agroforex Company to the Codex Committee on Food Additives for evaluation as a food additive. For this purpose, the present paper reports the phytochemical characterisation of both the volatile and non-volatile fractions of benzoin balsams and the quantitation of some of the major components by gas and liquid chromatography techniques. Four coniferyl and two morinol derivatives were characterised for the first time in Benzoe tonkinensis Laos. Finally, two liquid chromatographic methods used to easily discriminate Siam from Sumatra balsam (also known as Benzoe sumatranus Indonesia) were developed.

Composition and antifungal activity of the essential oil of Nashia inaguensis Millsp. (Verbenaceae) cultivated in French Guiana

Abstract This study reports the chemical composition of the essential oil of Nashia inaguensis Millsp. organically cultivated in French Guiana. This essential oil was examined by a combination of GC/FID and GC-MS techniques. A total of thirty-one components accounting for 97% of the total GC/FID chromatogram were identified. The most abundant ones were carvacrol (23.1%), p-cymene (18.7%), γ-terpinene (14.6%), thymol methyl ether (10.3%), thymol (8.3%), trans-β-caryophyllene (8.0%) and myrcene (2.3%). The essential oil of N.inaguensis was tested for the first time for antifungal and antiparasitic activities against strains of several Candida spp. and Leishmania guyanensis respectively: the strong antimicrobial activity of this essential oil was confirmed in vitro by the definition of MIC values ranging from 125 μg/mL to 500 μg/mL according to the Candida species tested, while the anti-Leishmania activity assessed by the definition of an IC50 value seem negligible.

UHPLC-HRMS/MS Based Profiling of Algerian Lichens and Their Antimicrobial Activities

Lichens are complex symbiotic organisms able to produce a vast array of compounds. The Algerian lichen diversity has only prompted little interest even given the 1085 species listed. Herein, the chemodiversity of four Algerian lichens including Cladonia rangiformis, Ramalina farinaceae, R. fastigiata, and Roccella phycopsis was investigated. A dereplication strategy, using ultra high performance liquid chromatography‐high resolution‐electrospray ionization‐mass spectrometry (UHPLC‐HRMS/MS), was carried out for a comprehensive characterization of their substances including phenolics, depsides, depsidones, depsones, dibenzofurans, and aliphatic acids. Some known compounds were identified for the first time in some species. Additionally, the lichenic extracts were evaluated for their antifungal and antimicrobial activities on human pathogenic strains (Candida albicans, C. glabrata, Aspergillus fumigatus, Staphylococcus aureus, and Escherichia coli). Cyclohexane extracts were found particularly active against human pathogenic fungi with MIC80 values ranging from 8 to 62.5 μg/mL, without cytotoxicity. This study highlights the therapeutic and prophylactic potential of lichenic extracts as antibacterial and antifungal agents.

Chemical composition, antimicrobial and insecticidal activities of flowers essential oils of Alpinia zerumbet (Pers.) from Martinique Island

Alpinia species, used as ornamental plants and flavoring agents, are renowned for their therapeutic properties and their subsequent use in traditional medicines throughout the world. Alpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm. is the most common Alpinia species encountered in Martinique. Several essential oils (EOs) obtained by hydrodistillation of A. zerumbet flowers collected in various locations on the island at different seasons were analysed to evaluate the influence of the collection period and area on the EOs’ chemical compositions and to assess their bioactivity. A combination of GC‐FID and GC/MS techniques was used to examine the volatile constituents, leading to the identification of a total of 71 components accounting for 97.8 – 99.3% of the respective total GC‐FID areas: among them, nineteen compounds were characterized for the first time in A. zerumbet EOs. The antimicrobial activity of these EOs was assessed against eight bacterial, yeast and fungal strains and two multi‐resistant strains: some significant bacteriostatic and fungistatic activities of A. zerumbet flower oils were evidenced. Finally, an interesting insecticidal activity of the flower EO was highlighted for the first time against Aedes aegypti.

Vetiver Essential Oil in Cosmetics: What Is New?

Background: Vetiver is a key ingredient for the perfume industry nowadays. However, with the constant and rapid changes of personal tastes, this appeal could vanish and this sector could decline quite quickly. New dissemination paths need to be found to tap this valuable resource. Methods: In this way, its potential use in cosmetics either as an active ingredient per se (with cosmeceutical significance or presenting antimicrobial activity) has hence been explored in vitro. Results: In this contribution, we demonstrated that vetiver essential oil displays no particularly significant and innovative cosmetic potential value in formulations apart from its scent already largely exploited. However, evaluated against twenty bacterial strains and two Candida species using the in vitro microbroth dilution method, vetiver oil demonstrated notably some outstanding activities against Gram-positive strains and against one Candida glabrata strain. Conclusions: Based on these findings, vetiver essential oil appears to be an appropriate aspirant for the development of an antimicrobial agent for medicinal purposes and for the development of a cosmetic ingredient used for its scent and displaying antimicrobial activity as an added value.

Chemical composition and antifungal activity of the essential oil of Varronia schomburgkii (DC.) Borhidi (Cordiaceae) from plants cultivated in French Guiana

Abstract This study reports for the first time the chemical composition of the essential oil of Varronia schomburgkii (DC.) Borhidi cultivated in French Guiana. This essential oil was examined by a combination of GC/FID and GC-MS techniques and was further tested for antifungal activity against several Candida strains, as well as for anti-leishmanial activity against the reference strain Leishmania guyanensis. A total of 45 components accounting for 93.61% of the total GC/FID chromatogram were identified. The essential oil is dominated by sesquiterpenes and oxygenated sesquiterpenes among which β-caryophyllene (46.99 ± 0.32%) is the major one. No anti-leishmania activity could be assessed, while a strong antimicrobial activity of this essential oil was evidenced in vitro against a Candida albicans strain by the definition of a MIC value of 250 μg/mL. V. schomburgkii essential oil might hence be considered in the future for the development of natural antifungal agents.

Corrigendum of the article: ‘Composition and antifungal activity of the essential oil of Nashia inaguensis Millsp. (Verbenaceae) cultivated in French Guiana’ published in the journal of essential oil research (DOI: 10.1080/10412905.2016.1142477)

Abstract In a recent publication (DOI: 10.1080/10412905.2016.1142477), we presented the composition and antifungal activity of the essential oil of allegedly Nashia inaguensis Millsp. (Verbenaceae) using material from plants cultivated in French Guiana. A recent taxonomic revision of the genus Nashia, including a complete description of N. inaguensis, called our attention, as certain morphological characters did not correspond with those of our voucher specimen. An accurate re-examination of the voucher specimen and the original cultivated plants, and a comparison with the complete description of Lippia species present in the Guianas, confirmed that the species we studied was actually L. micromera Schauer. The present corrigendum aims to revise the botanical characterization presented in the aforementioned article. The chemical composition and antifungal activity of the essential oil of interest are then discussed in light of this corrected taxonomic identification in comparison with previous studies of L. micromera essential oil. The authors apologize for the error.

Identification of antibiotic and antiproliferative compounds in natural orange blossom water

Abstract Orange blossom water (Citrus aurantium L. ssp aurantium) is a hydrosol widely used in cosmetics, medicine and in the food industry. When exposed to sunlight for a few days, the hydrosol turns orange and a precipitate appears afterwards. Despite the economic importance of the orange blossom water, this phenomenon has never been studied and the chemical changes taking place have never been elucidated. This study reports on the comparative analysis of sunlight exposed and non-exposed hydrosols by UV-Visible spectroscopy, GC and HPLC. The formation of several indole derivatives (isatin, oxindole, indole-3-carboxaldehyde, 3,3’-diindolylmethane, turbomycin A) induced by the exposition of orange blossom water to sunlight was observed. Two of these derivatives have already been identified as biologically active compounds: 3,3’-diindolylmethane displays an antiproliferative activity against various human cancer cell lines and turbomycin A presents a broad-range antibiotic activity. The later one was identified in this study as the compound responsible for the orange coloration of sunlight-exposed orange blossom water.