China
Africa
Explore chapters and articles related to this topic
Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Citronellal is a colorless to pale yellow clear liquid; its odor type is floral and its odor is described as ‘sweet, floral rosy waxy and citrus green’ (www.thegoodscentscompany.com). Citronellal is used in small amounts for scenting soaps and detergents, is also used as flavor in foods and beverages and is applied as insect repellent. Its principal application, however, is in the preparation of isopulegol, citronellol, and hydroxycitronellol (U.S. National Library of Medicine).
Chemistry of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
The two most significant monoterpene aldehydes are citral (71) and its dihydro analogue citronellal (103), both of which are shown in Figure 6.20. The word citral is used to describe a mixture of the two geometric isomers geranial (101) and neral (102) without specifying their relative proportions. Citral occurs widely in nature, both isomers usually being present, the ratio between them usually being in the 40:60 to 60:40 range. Lemongrass contains 70%–90% citral and the fruit of Litsea cubeba contains about 60%–75%. Citral also occurs in Eucalyptus staigeriana, lemon balm, ginger, basil, rose, and citrus species. It is responsible for the characteristic smell of lemons although lemon oil usually contains only a few percent of it. Citronellal (103) also occurs widely in essential oils. E. citriodora contains up to 85% citronellal, and significant amounts are also found in some chemotypes of L. cubeba, citronella Swangi leaf oil, and Backhousia citriodora. Campholenic aldehyde (104) occurs in a limited range of species such as olibanum, styrax, and some eucalypts. Material produced from a-pinene (65) is important as an intermediate for synthesis.
Monoterpenes-Based Pharmaceuticals: A Review of Applications In Human Health and Drug Delivery Systems
Published in Megh R. Goyal, Durgesh Nandini Chauhan, Plant- and Marine-Based Phytochemicals for Human Health, 2018
Irina Pereira, Aleksandra Zielińska, Francisco J. Veiga, Ana C. Santos, Izabela Nowak, Amélia M. Silva, Eliana B. Souto
Citral is classified as αand β-unsaturated aldehydes.139 Therefore, it can be used as a model substance for heterogeneously catalyzed selective hydrogenations. The hydrogenation process of the carbonyl group is insignificant when palladium is put on as an active metal. Then, the conjugated C = C bond is hydrogenated prior to the terminal isolated one. As a result of this reaction, citronellal (CAL) and dihydrocitronellal are obtained as main products.139 The main chemical and physical properties of citral are shown in Table 4.1.55 Physicochemical properties of citral are rare, in spite of that its hydrogenation products influence positively on chemicals and perfume industry.84
Volatile, non-volatile composition and insecticidal activity of Eupatorium adenophorum Spreng against diamondback moth, Plutella xylostella (L.), and aphid, Aphis craccivora Koch
Published in Toxin Reviews, 2019
Olonisakin Adebisi, Shudh Kirti Dolma, Praveen Kumar Verma, Bikram Singh, S. G. Eswara Reddy
The repellent activity of EO against third instar larvae of P. xylostella in terms of RC50 to show 50% repellence to test insect and other statistical parameters are summarized in Table 8. EO and its constituents are currently used as repellents, exploiting the relationship between EO constituents and repellency, and by studying the synergistic effects developed with the mixtures. The common monoterpenes viz. limonene, eugenol a-pinene, cineole, terpinolene, citronellal, citronellol, camphor, and thymol present in the EOs are accountable of repellent activity reviewed in the literature. In the present study, EO of E. adenophorum showed promising repellent activity to larvae of P. xylostella (RC50 = 2070.99 mg L−1). Our studies are in conformity with the findings of other researchers who reported EO of Cedrus deodara (Roxb.), Tagetus minuta L., and Acorus calamus L. at 10 mg m L−1 showed 48 to 65% repellency to larvae of P. xylostella (Reddy et al.2016). Other studies described the EOs of different plants showed repellency to Diptera (Ansari et al.2000) and Coleopteron insects (Papachristos and Stamopoulos 2002). In another study, EOs of Ruta graveolens L., Allium sativum L., Pogostemom cablin (Blanco), and Tanacetum vulgare L. indicated good repellent activity to Lepidopteron larvae of Cydia pomonella (Landolt et al.1999).
Review of Antimicrobial and Other Health Effects in 5 Essential Oil Producing Grass Species
Published in Journal of Dietary Supplements, 2023
Lemongrass leaves have shown to have anti-inflammatory properties via proteasome inhibition, NF-κB pathway, and cytokine expression (Francisco et al. 2013). Lemongrass extracts have been reported to reduce human lymphoma tumor growth (Philion et al. 2017). A clinical trial using 0.25% lemongrass oil mouthwash showed the highest reduction in plaque and gingival indexes when compared to a 0.2% chlorhexidine mouthwash (Dany et al. 2015). In fact, Subha and Pradeep (2017) showed in a clinical trial that a 0.25% concentration of lemongrass oil aided in chronic periodontitis and reduced markers of cardio-vascular diseases. Gastroprotective effects have been shown in rats fed with lemongrass leaf infusion (Sagradas et al. 2015). Lemongrass oil has been shown to be effective against prostate cancer and glioblastoma cell lines (Bayala et al. 2018). Polysaccharides of lemongrass may help in preventing or treating neurodegenerative diseases where neuro-inflammation is part of the problem (Mediesse et al. 2018). Machado et al. (2015) reported that a lemongrass hexane extract helped control allergic asthma in mice. A 20% solution of lemongrass oil showed an inhibition against Aeromonas salmonicida ssp. salmonicida which causes fish furunculosis disease (Starliper et al. 2015) and the main biochemicals in the lemongrass oil included eugenol α- and β-citral. Citronellal which has been found in lemongrass oil has the potential to prevent atherosclerosis in rats (Lu et al. 2019). Another component of lemongrass oil is linalool which has been reported to lower blood pressure and pulse rate in people with carpal tunnel syndrome (Seol et al. 2016).
Acaricidal activities of essential oils against two-spotted spider mite, Tetranychus urticae Koch
Published in Toxin Reviews, 2018
S. G. Eswara Reddy, Shudh Kirti Dolma
Majority of EO and its constituents presently used as repellents, exploiting the association between oil constituents and repellent activity, reviewing the synergistic effects attained with the mixtures. The common monoterpenes such as limonene, α-pinene, cineole, eugenol, terpinolene, citronellol, citronellal, camphor and thymol present in the EOs are responsible of repellent activity reported in the literature. Our results are in conformity with the findings of other workers who reported repellent activity to T. urticae adults. The EO from leaves and fruits of Protium bahianum Daly showed promising repellent activity to adult T. urticae (Pontes et al., 2007,2010). Similarly, Piper aduncum L. oil showed 96% repellency to T. urticae which is due to (E)-nerolidol, α-humulene and β-caryophyllene (Araujo et al., 2012). EOs of Callistemon sieberi DC, E. bicostata, Eucalyptus ovata Labill, E. sideroxylon, Eucalyptus mannifera Mudie, E. dives, Eucalyptus elata (El), E. condonocarpa Blakely & Mc Kie, Kunzea ericoides (A. Rich) Joy Thomps, Melaleuca armillaris (Sol. ex Gaertn) Sm and Melaleuca fulgens R. Br. showed good repellency to adult T. urticae (Roh et al., 2013). In other study, M. pulegium at 1000 mg L−1 air also showed 100% repellency (Mozaffari et al., 2013) and Elettaria cardamomum L. at 7000 mg L−1 showed 67.9% repellency to adult T. urticae (Fatemikia et al., 2014). EO of Lavandula x intermedia Emeric ex Loisel and Hyssopus officinalis L. showed repellency (51% and 60%, respectively) to adult T. urticae (Salman et al., 2015). Sygygium aromaticum (L.) and M. spicata showed most potent repellency against adult T. urticae (Kheradmand et al., 2015). In a related studies against other insect pests, EO of Cedrus deodara (Roxb.), Tagetus minuta L. and Acorus calamus L. @10 mg mL−1 showed 48–65% repellency to third instar larvae of Plutella xylostella Linnaeus (Reddy et al., 2016). Other studies described the EOs of different plants showed repellent activity to Diptera (Ansari et al., 2000) and Coleopteron insects (Papachristos & Stamopoulos, 2002).