There is an urgent and unmet need for new antifungal therapies. Global fungal infection rates continue to rise and fungal infections pose increasing burdens on global healthcare systems. Exacerbating the situation, the available antifungal therapeutic arsenal is limited and development of new antifungals has been slow. Current antifungals are known for unwanted side effects including nephrotoxicity and hepatotoxicity. Thus, the need for new antifungals and new antifungal targets is urgent and growing. A collection of 60 commercially-available essential oils has been screened for antifungal activity against Aspergillus niger, Candida albicans, and Cryptococcus neoformans, as well as for cytotoxic activity against MCF-7 and MDA-MB-231 human breast tumor cell lines; the chemical compositions of the essential oils have been determined by gas chromatography-mass spectrometry (GC-MS). Ten essential oils showed remarkable antifungal and cytotoxic activities: Indian, Australian, and Hawaiian sandalwoods; melissa; lemongrass; cilantro; cassia; cinnamon; patchouli; and vetiver.

Black pepper (Piper nigrum) is historically one of the most important spices and herbal medicines, and is now cultivated in tropical regions worldwide. The essential oil of black pepper fruits has shown a myriad of biological activities and is a commercially important commodity. In this work, five black pepper essential oils from eastern coastal region of Madagascar and six black pepper essential oils from the Amazon region of Brazil were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components of the essential oils were α-pinene, sabinene, β-pinene, δ-3-carene, limonene, and β-caryophyllene. A comparison of the Madagascar and Brazilian essential oils with black pepper essential oils from various geographical regions reported in the literature was carried out. A hierarchical cluster analysis using the data obtained in this study and those reported in the literature revealed four clearly defined clusters based on the relative concentrations of the major components.

Cymbopogon species essential oil (EO) carries significant importance in pharmaceuticals, aromatherapy, food, etc. The chemical compositions of Cymbopogon spp. Viz. Cymbopogon winterianus (citronella) Cymbopogon citratus (lemongrass), and Cymbopogon martini (palmarosa) were analyzed by gas chromatography–mass spectrometry (GC-MS), enantiomeric distribution by chiral GC-MS, and antimicrobial activities of some selected pure major compound and root and leaves EOs of citronella. The EO of leaves of Cymbopogon spp. showed comparatively higher yield than roots or other parts. Contrary to citral (neral and geranial) being a predominant compound of Cymbopogon spp., α-elemol (53.1%), α-elemol (29.5%), geraniol (37.1%), and citral (90.4%) were detected as major compounds of the root, root hair with stalk, leaf, and root stalk with shoot of citronella EO, respectively. Palmarosa leaves’ EO contains neral (36.1%) and geranial (53.1) as the major compounds. In the roots of palmarosa EO, the prime components were α-elemol (31.5%), geranial (25.0%), and neral (16.6%). Similarly, lemongrass leaves’ EO contains geraniol (76.6%) and geranyl acetate (15.2%) as major compounds, while the root EO contains a higher amount of geraniol (87.9%) and lower amount of geranyl acetate (4.4%). This study reports for the first time chiral terpenoids from Cymbopogon spp. EOs. Chiral GC-MS gave specific enantiomeric distributions of nine, six, and five chiral terpenoids in the root, root stalk with a shoot, and leaves of citronella EOs, respectively. Likewise, four and three chiral terpenoids in the root and leaves of lemongrass oil followed by two chiral terpenoids in the leaves and root of palmarosa EOs each. Additionally, the root and leaves’ EOs of citronella exhibit noticeable activity on bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and fungus such as Candida albicans, Microsporum canis, and Trichophyton mentagrophytes. So, geranial-, neral-, geraniol-, and citronellal-rich EOs can be used as an alternative antimicrobial agent.

Essential oils are promising as environmentally friendly and safe sources of pesticides for human use. Furthermore, they are also of interest as aromatherapeutic agents in the treatment of Alzheimer’s disease, and inhibition of the enzyme acetylcholinesterase (AChE) has been evaluated as an important mechanism. The essential oils of some species in the genera Callicarpa, Premna, Vitex and Karomia of the family Lamiaceae were evaluated for inhibition of electric eel AChE using the Ellman method. The essential oils of Callicarpa candicans showed promising activity, with IC₅₀ values between 45.67 and 58.38 μg/mL. The essential oils of Callicarpa sinuata, Callicarpa petelotii, Callicarpa nudiflora, Callicarpa erioclona and Vitex ajugifolia showed good activity with IC₅₀ values between 28.71 and 54.69 μg/mL. The essential oils Vitex trifolia subsp. trifolia and Callicarpa rubella showed modest activity, with IC₅₀ values of 81.34 and 89.38, respectively. trans-Carveol showed an IC₅₀ value of 102.88 µg/mL. Molecular docking and molecular dynamics simulation were performed on the major components of the studied essential oils to investigate the possible mechanisms of action of potential inhibitors. The results obtained suggest that these essential oils may be used to control mosquito vectors that transmit pathogenic viruses or to support the treatment of Alzheimer’s disease.

Cinnamomum camphora L. is grown as an ornamental plant, used as raw material for furniture, as a source of camphor, and its essential oil can be used as an important source for perfume as well as alternative medicine. A comparative investigation of essential oil compositions and antimicrobial activities of different tissues of C. camphora was carried out. The essential oils were extracted by hydrodistillation with a Clevenger apparatus and their compositions were evaluated through gas chromatography-mass spectrometry (GC-MS), enantiomeric composition by chiral GC-MS, and antimicrobial properties were assayed by measuring minimum inhibitory concentrations (MICs). Different plant tissues had different extraction yields, with the leaf having the highest yield. GC-MS analysis revealed the presence of 18, 75, 87, 67, 67, and 74 compounds in leaf, branch, wood, root, leaf/branch, and leaf/branch/wood, respectively. The significance of combining tissues is to enable extraction of commercial quality essential oils without the need to separate them. The oxygenated monoterpene camphor was the major component in all tissues of C. camphora except for safrole in the root. With chiral GC-MS, the enantiomeric distributions of 12, 12, 13, 14, and 14 chiral compounds in branch, wood, root, leaf/branch, and leaf/branch/wood, respectively, were determined. The variation in composition and enantiomeric distribution in the different tissues of C. camphora may be attributed to the different defense requirements of these tissues. The wood essential oil showed effective antibacterial activity against Serratia marcescens with an MIC of 39.1 μg/mL. Similarly, the mixture of leaf/branch/wood essential oils displayed good antifungal activity against Aspergillus niger and Aspergillus fumigatus while the leaf essential oil was notably active against Trichophyton rubrum. C. camphora essential oils showed variable antimicrobial activities against dermal and pulmonary-borne microbes.

Curcuma species have been cultivated in tropical and subtropical regions in Asia, Australia, and South America for culinary as well as medicinal applications. The biological activities of Curcuma have been attributed to the non-volatile curcuminoids as well as to volatile terpenoids. Curcuma essential oils have demonstrated a wide variety of pharmacological properties. The objective of this work was to examine the variation in the compositions of Curcuma rhizome essential oils. In this work, the volatile oils from C. longa and C. zedoaria were obtained and analyzed by gas chromatography-mass spectrometry. The chemical compositions of C. longa and C. zedoaria essential oils, including those reported in the literature, were analyzed by hierarchical cluster analysis. In addition, cluster analyses of the chemical compositions of C. aromatica and C. aeruginosa from the literature were also carried out. Curcuma longa volatiles were dominated by α-turmerone, curlone, ar-turmerone, β-sesquiphellandrene, α-zingiberene, germacrone, terpinolene, ar-curcumene, and α-phellandrene and showed four distinct chemical clusters. C. zedoaria rhizome oil contained 1,8-cineole, curzerenone/epi-curzerenone, α-copaene, camphor, β-caryophyllene, elemol, germacrone, curzerene, and β-elemene and showed two different chemical types. C. aromatica had three clearly defined clusters, and C. aeruginosa had three types.