It was first isolated by O. Jacobsen in 1871. Geraniol terpenes are popular for their sweet, floral, and citrusy notesas well as their calming effects. National Library of Medicine Tunable Production of (R)- or (S)-Citronellal from Geraniol via a Several NFCs under consideration, such as Balm Oil (FEMA 2113), Citronella Oil (FEMA 2308) and Lemongrass Oil (FEMA 2624), have a lemon-like character. The acetylation of monoterpene alcohols and conversion of geraniol to citronellol are catalyzed by the enzymes encoded in ATF1 and OYE2 genes, respectively (Steyer etal. Find a chemistry community of interest and connect on a local and global level. CAS It is the primary component of citronella oil and is a primary component of rose oil, palmarosa oil. Clipboard, Search History, and several other advanced features are temporarily unavailable. government site. Google Scholar, Catharino RR, Haddad R, Cabrini LG, Cunha IBS, Sawaya ACHF, Eberlin MN (2005) Characterization of vegetable oils by electrospray ionization mass spectrometry fingerprinting: classification, quality, adulteration, and aging. 2010a). Geraniol is a chemical compound in the terpene family. Geraniol - Wikipedia We know you're incredibly busy, so here are the key takeaways: Geraniol is an acyclic monoterpene alcohol (but don't drink it!). This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (, Chemical and genetic carotenoid deficiency delays growth in dark-grown Euglena gracilis, Pharmacokinetic profiles of 3-(4-hydroxy-3-methoxyphenyl) propionic acid and its conjugates in Sprague-Dawley rats, Photosynthetic 1,8-cineole production using cyanobacteria, Identification of a derivative of the alkaloid emetine as an inhibitor of the YAP-TEAD interaction and its potential as an anticancer agent, Identification of genes responsible for absorbing palladium ion in Escherichia coli, About Bioscience, Biotechnology, and Biochemistry, About Japan Society for Bioscience, Biotechnology, and Agrochemistry, https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model, Receive exclusive offers and updates from Oxford Academic, Copyright 2023 Japan Society for Bioscience, Biotechnology, and Agrochemistry. Although geranic acid and citronellic acid were detected in the chromatogram of geraniol-added medium, their peaks were much smaller than those detected in geraniol-added BY4741 culture (Figure1a and b). Plant Cell Rep 20:437444, Schulz H, Ozkanb G, Baranska M, Kruger H, Ozcan M (2005) Characterization of essential oil plants from Turkey by IR and Raman spectroscopy. Overall, however, the geraniol candle provided significantly more protection than the citronella candle, (Tukey-Kramer Test p<0.05) the geraniol being about five times as effective as the citronella in protecting a person from Ae. Like all commercially sold products that are intended to be applied to human skin, the EPA requires proper precautionary labeling on some insect repellents containing citronella so people know how to safely use it. To clarify the metabolic pathways from geraniol/nerol to geranic acid and from geraniol/nerol to citronellic acid, potential substrates for biosyntheses of geranic acid and citronellic acid were added to BY4741 culture. Careers. Some animal studies have even shown that inhalation of citronella can help reduce appetite and potentially body weight, perhaps by reducing stress-related cravings. As the peaks of geranic acid and citronellic acid were detected as broad peaks, the quantification of these monoterpene carboxylic acids was performed after methyl esterification. Accessibility Dev Mani Pandey. Please enable it to take advantage of the complete set of features! Kinetic investigation of commercially available alcohol dehydrogenases showed that the activity of Adh1p decreased with increasing chain length of the primary alcohols (De Smidt, Du Preez and Albertyn 2008). UGC, New Delhi, India is gratefully acknowledged for providing financial support to Ms. Aakanksha Wany (F1-17.1/2012-13/MANF-2012-13-CHR-CHH-9539) as JRF. Citronella oil is the main product of Java citronella grass (Cymbopogon winterianus Jowitt) rich in geraniol and citronellol, widely used in mosquito repellents and perfumeries. Kongkaew C, Sakunrag I, Chaiyakunapruk N, Tawatsin A. Trop Med Int Health. and I.M. When the actions of geraniol and citronellal were compared, geraniol was found to have a higher larvicidal action than citronellal (P < 0.05) at concentrations of 250 and 31.2 g/mL and citronellal was found to have a higher larvicidal activity than geraniol (P < 0.005) at concentrations of 125 and 62.5 g/mL. HHS Vulnerability Disclosure, Help Solved You 15 The structures of geraniol and citronellal are | Chegg.com Sanekata A, Tanigawa A, Takoi K et al. KEYWORDS: biocatalysis, biocascade, citronellal, citral, geranial, enzymatic oxidation, enzymatic reduction . 2021 Society for Experimental Biology and John Wiley & Sons Ltd. The geraniol 10-hydroxylase was purified from seedlings and cell cultures, and the activity reconstituted. Monoterpenoid means that geraniol contains two copies of the building block isoprenes. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Iijima M, Kenmoku H, Takahashi H, Lee JB, Toyota M, Asakawa Y, Kurosaki F, Taura F. Nat Prod Commun. In addition, the molecular ion of nerol (m/z=154) and citronellol (m/z=156) were extracted from the total-ion count peak corresponding to citronellol detected in the BY4741 culture where geraniol was added (Figure S3). 2013), is dominantly converted to citronellol or citronellic acid. Zhang JW, Li BY, Lu XX, Zheng Y, Wang D, Zhang Z, Zeng D, Du SS. Would you like email updates of new search results? Note that the numbers in parentheses (1, 2, etc.) As an easy-to-make home remedy for acne, try dabbing one drop of pure citronella essential oil mixed with one drop of coconut oil on blemishes three times a day using a sterile cotton swab. Many monoterpenes found in marine organisms are halogenated, such as halomon. Figure 3 shows the results of their catalytic activity. Would you like email updates of new search results? A major source of these compounds is the essential oil of rose-scented geraniums of the genus Pelargonium. From these results, the enzymatic conversions of geraniol to citronellol, geranic acid, and citronellic acid were focused (Figure2). Almagro Armenteros, J.J., Tsirigos, K.D., Snderby, C.K., Petersen, T.N., Winther, O., Brunak, S. et al. Google Scholar, Silva CF, Moura FC, Mendes MP, Pessoa FLP (2011) Extraction of citronella (Cymbopogon nardus) essential oil using supercritical carbon dioxide: experimental data and mathematical modeling. GC-MS chromatograms of extracts from BY4741 culture and medium without yeast inoculation after 10-d incubation. Conclusion: Geraniol Terpenes Pack a Punch, today if youre interested in using geraniol in any of your products! Like many citrus essential oils, citronella contains compounds that fight free radical damage and help reverse oxidative stress. Pharm Biol 46:437441, Vargas CE, Mendes MF, Azevedo DA, Pessoa FLP, Uller AC (2010) Extraction of the essential oil of abajeru (Chrysobala musicaco) using supercritical CO2. Unauthorized use of these marks is strictly prohibited. Theyre thought to contribute to aging, arteriosclerosis, and asthma (9). PDF CHEM1101 2014-J-3 June 2014 - University of Sydney Explore the interesting world of science with articles, videos and more. Antimicrobial and antioxidant properties of Cymbopogon. It can help with management of inflammation and painful symptoms like joint aches. In contrast, (-)-isomenthone-rich lines are depleted in these prenyl monophosphates and monoterpene alcohols and instead feature high levels of GDP, the precursor to plastidic p-menthane biosynthesis. Biosyntheses of geranic acid and citronellic acid from monoterpene The chromatographic analysis of essential oils with respect to standards geraniol and citronellol were studied by high performance thin layer chromatography (HPTLC) with n-hexane and ethyl acetate (3:2) as mobile phase followed by its separation on plates. In the case of geraniol and anisaldehyde, exposure to concentrations higher than 0.025 g/cm 3 for 24 h induced inhibition of complete engorgement. If your favorite molecule is not in ourarchive, please send an email toacs-motw@acs.org. Cytosolic geraniol and citronellol biosynthesis require a Nudix It acts as an effective antimicrobial and antibacterial. Add several drops to a spray bottle along with water, shake it up and spray it throughout your home and on household items. Monoterpene - Wikipedia Its structure is similar to that of nerol, also a rose scent ingredient. This is a preview of subscription content, access via your institution. RSC Adv. Geraniol and citronellol as alternative and safe - ScienceDirect These results indicate more potent activation of PPAR by citronellol than by geraniol, possibly due to the replace-ment of the geraniol double bond with the single bond of Menthol - BASF Menthol Process -Page 13 - Leffingwell Studies have shown that geraniol can fight inflammatory responses in the body. What insects does citronella oil repel? In these gene-deficient strains, therefore, cells might be maintained in more reductive redox state in the absence of Adh4p or Adh6p. Ability of essential oil candles to repel biting insects in high and low biting pressure environments. Cymbopogon winterianusmain active ingredients include: Of the two types, Java is thought to be more powerful, and therefore its usually more expensive. Bookshelf Sharp DC, Qian Y, Shellhammer G et al. 2023 Jan 9;13(3):1659-1671. doi: 10.1039/d2ra06273a. Genet Resour Crop Evol 47:553559, Article Plants traditionally used as mosquito repellents and the implication for their use in vector control. Yuka Ohashi, Shuai Huang, Isamu Maeda, Biosyntheses of geranic acid and citronellic acid from monoterpene alcohols by Saccharomyces cerevisiae, Bioscience, Biotechnology, and Biochemistry, Volume 85, Issue 6, June 2021, Pages 15301535, https://doi.org/10.1093/bbb/zbab039. Its sweet, floral, and citrusy notes work well in perfumes and creams. According to the ASPCA, research has shown that a citronella collar can be at least as effective for eliminating barking as an electronic collar, and its typically viewed more positively by dog owners. A Doctor's advice should be sought before using this and any supplemental dietary product. In fact, there have been virtually zero reports of adverse effects of concern since 1948. Table 2 According to various studies investigating the effects of these compounds, citronella oil has been shown to have the following health-promoting effects: Today, there are more than 30 species of Cymbopogon (citronella plants) grown wildly throughout parts of the world and used in Southeast Asian cooking and teas. The biotransformation study of monoterpene alcohols during fermentation of hopped beer using various hop cultivars has revealed that the concentrations of geraniol and citronellol in finished beer increase, depending on the initial concentration of geraniol in the wort (Takoi etal. Nng cao ca citronellal trong bch n chanh to ra mt mi hng ti mt v c tnh ng dng cao . Newer Post. As a concentrated form of antioxidants and phytochemicals taken from the plants stems and leaves, citronella oil has been used for centuries in China, Indonesia and Sri Lanka. 2022 Abstrax Tech. The stationary phase (silica) is polar and will hold onto the more polar compounds longer. According to a review published by the, , geraniol sensitizes tumor cells to commonly used chemotherapy agents (. Many aroma compounds have been characterized in various kinds of alcoholic beverages. Studies suggest geraniol also works as an effective pesticide against various types of even smaller critters (like the kind from your darkest nightmares you can only see with a microscope). Benefits of this citrusy oil include acting as a natural pest repellent, anti-inflammatory pain reliever, stress reducer, parasite destroyer, cleaning aid and natural deodorizer. However, no other genes involved in terpenoid conversion have been identified in S. cerevisiae. Synthesis of Citronellal by RhICatalysed Asymmetric Isomerization of N A brewing strain S. cerevisiae NCYC 1681 was purchased from National Collection of Yeast Cultures (Norwich, UK). These concentrations started to increase at the 4th day, and remarkable production was observed from the 8th day to 10th day in BY4741 (Figure3a). Bethesda (MD): National Institute of Child Health and Human Development; 2006. The Mosquito Repellent Activity of the Active Component of Air Geraniol is monoterpene alcohol that is a main ingredient of rose oil; it also is present in many other essential oils. This site needs JavaScript to work properly. The age of the plant plays a key role in oil composition and its yield such that young leaves have lesser oil content than the mature leaves. Citral - Wikipedia This work was supported by a research fund to I.M. For over 2000 years, balm (Melissa officinalis L.) has been used as a sweetening herb. In vitro research shows that geraniol also has strong anti-helminthic activity. Epub 2019 Nov 4. sharing sensitive information, make sure youre on a federal This is the first report of the bioconversion of monoterpene alcohols, geraniol and nerol, to geranic acid and citronellic acid in yeast culture. Please enable it to take advantage of the complete set of features! The concentrations of citronellic acid with citronellol and geranic acid were less than 5 g/mL, suggesting that citronellic acid might be directly converted from citronellal without passing through citronellol and geranic acid (Figure5). ). Citronella essential oil is not recommended for use by pregnant women due to safety concerns. It should not be used if you are pregnant or nursing. government site. Geranic acid and citronellic acid were detected in yeast culture, where geraniol or nerol was added. According to a review published by the International Journal of Oncology, geraniol sensitizes tumor cells to commonly used chemotherapy agents (11). This doesnt mean you should go out and stuff your face with Big Macs thinking geraniol will immediately solve the resulting health issues. Keywords: In addition to keeping away bugs, it also helps kill bacteria and nourish your skin, and unlike conventional brands, it smells amazing! These bacteria can make you sick and may even cause death in severe cases when left untreated. The solvent collected at the bottom of the column can be collected and separated over time. The various methods of extracting essential oils from citronella grass with respect to yield (%) were studied. 2020). 2015). In addition to conversions of geraniol to citronellol and linalool, which have been reported previously (King and Dickinson 2000), conversions of geraniol to geranic acid and citronellic acid were detected after cultivation (Figure 1a). 5.10: Electronegativity and Bond Polarity - Chemistry LibreTexts The almost same concentration of geranic acid was detected with citral, a mixture of geranial (E isomer) and neral (Z isomer), compared to the concentration with geraniol. According to some research, you need to reapply citronella oil about every 3060 minutes for its bug-deterring effects to last. The dichloromethane solution was transferred to an eggplant flask by a Komagome pipette, and dichloromethane was evaporated with a rotary evaporator. Main examples Seasonal metabolic profiling of Valencia orange leaf essential oil using GC coupled with chemometrics, nano-formulation, and insecticidal evaluation: Neuromodulation and differential learning across mosquito species. Federal government websites often end in .gov or .mil. The Java type is similar and derived from a related species called Cymbopogon winterianus. Because it has a clean, fresh scent similar to lemon or lemongrass, citronella is a common ingredient in soaps, candles, incense, perfumes and cosmetics. Anecdotal evidence suggests allergic contact dermatitis, or sensitive human skin irritation, may be a side effect of topical geraniol use (15). Pelargonium graveolens; Geraniaceae; Nudix hydrolase; essential oil; fragrance biosynthesis; glandular trichomes; monoterpene biosynthesis; plant volatiles. Its a good idea to start out using it in small amounts and performing a skin patch test to make sure you dont experience any citronella oil side effects like allergies, redness, swelling or hives. A major source of these compounds is the essential oil of rose-scented geraniums of the genus Pelargonium. Finally, researchers found essential oil with geraniol as its main active ingredient kills tiny parasitic worms found in certain fish (6). The Protein Journal, 36(5), 425-432. . You can also inhale the oil directly by sniffing it. Search for other works by this author on: Terpenoids and their role in wine flavour: recent advances, Olfactory impact of higher alcohols on red wine fruity ester aroma expression in model solution, The molecular biology of fruity and floral aromas in beer and other alcoholic beverages, Biotransformation of monoterpene alcohols by, Biotransformation of hop aroma terpenoids by ale and lager yeasts, Linoleic acid, -linolenic acid, and monolinolenins as antibacterial substances in the heat-processed soybean fermented with, Influence of wine fermentation temperature on the synthesis of yeast-derived volatile aroma compounds, Identification and characterization of geranic acid as a unique flavor compound of hops (, Structural determinants of odorant recognition by the human olfactory receptors OR1A1 and OR1A2, Contributions of select hopping regimes to the terpenoid content and hop aroma profile of ale and lager beers, Genetic analysis of geraniol metabolism during fermentation, The contribution of geraniol metabolism to the citrus flavour of beer: synergy of geraniol and -citronellol under coexistence with excess linalool, Biotransformation of hop-derived monoterpene alcohols by lager yeast and their contribution to the flavor of hopped beer, Geraniol biotransformation-pathway in spores of, Molecular structure and genetic regulation of SFA, a gene responsible for resistance to formaldehyde in, Multiple forms of mitochondrial alcohol dehydrogenase in. Therefore, kinetic analyses of the recombinant Adh4p toward geraniol and nerol need to be further performed to confirm whether or not it is responsible for the primary oxidation step of geraniol. The higher concentrations of citronellol and the lower concentrations of geranic acid and citronellic acid were detected in the adh4 and adh6 strains, compared to those in BY4741 (Figure6a). S. cerevisiae BY4741 and its gene-deletion strains were purchased from Euroscarf (Frankfurt, Germany). Concentrations of geranic acid and citronellic acid produced in BY4741 culture for 10 d. Concentrations of geranic acid converted from geraniol, citral, and nerol (a) and citronellic acid converted from geraniol, citronellol, citronellal, citral, nerol, and geranic acid (b) were shown. Figure 5.10. [0003] However, since fragrances are usually poorly water-soluble or insoluble compounds it is often difficult to perfuming the products. These data suggest that BY4741 enzymes related to metabolism of monoterpene alcohols have higher affinities to geraniol than nerol. Citronella grass, Cymbopogon nardus, is a plant originated from Sri Lanka and India (Mahalwal and Mahalwal and Ali, 2003) that has shown antibacterial and antioxidant properties in vitro being widely used in teas for its soothing properties (Castro et al., 2010; Park et al., 2015). Geraniol, found in hops and Muscat as an aroma substance, and nerol, the diastereomer of geraniol, are converted to geranic acid and citronellic acid by yeast. What is Geraniol? 9 Powerful Uses and Benefits of this Potent Terpene Citronellal | C10H18O - PubChem Lemongrass essential oil can be confused for citronella essential oil and vice versa. and S.H. All three of these compounds are articles of commerce as fragrance ingredients used by the perfume industry. (1). According to scientific research, pure citronella essential oil is known to have amazing antibacterial and antifungal abilities. We use geraniol as a common additive to food and cosmetics for its full flavor and sweet rose aroma. Importance of geraniol as a substrate for conversion to citronellol and linalool (King and Dickinson 2000, 2003) and sterol biosynthesis (Steyer etal. The authors are grateful for the facility of FT-IR provided by the Central Instrumentation Facility, TEQIP, Department of Biotechnology, BIT, Mesra. It can also be diffused, burned as a candle or applied topically. If you're worried about creating or using a harmful fly or mosquito repellent, check this out: Geraniol candles repelled mosquitoes and sandflies five times more effectively than citronella candles and two times more effectively than linalool candles. 2018) and microorganisms (van der Werf and Wolken 2001) that geranic acid is formed from geraniol through the two-step process composed of oxidations of alcohol to aldehyde and aldehyde to carboxylic acid. The information in our articles is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. The decrease in citronellol and the remarkable increase in citronellic acid from the 8th day to the 10th day suggest possibility that citronellic acid might be converted from citronellol once produced and transferred to the medium. Note that the numbers in parentheses (1, 2, etc.) This is true for many substances you use daily, including soaps and detergents. Pelargonium graveolens chemotypes enriched in either geraniol or (-)-citronellol accumulate GP or citronellyl monophosphate (CP), respectively, the presumed precursors to their monoterpenoid end products. Citronella oil is the main product of Java citronella grass (Cymbopogon winterianus Jowitt) rich in geraniol and citronellol, widely used in mosquito repellents and perfumeries. The result suggests that ADH1, ADH3, ADH4, and SFA1 genes might be involved in the oxidation of geraniol and production of geranic acid, citronellic acid, and citronellol. A citronella plant, also called a mosquito plant, does resemble its relative, the lemongrass plant. It is commonly used in perfumes. Chemical building blocks called isoprenes make up terpenes, and geraniol is whats called an acyclic monoterpene alcohol. When geraniol was added to the medium without S. cerevisiae inoculation, linalool was also detected at a higher concentration rather than that in BY4741 culture (Figure1a and b). The dichloromethane solutions containing terpenoids were collected and then dehydrated with anhydrous magnesium sulfate. Geraniol - an overview | ScienceDirect Topics ChemLuminary Awards Chemical Diversity and Anti-Insect Activity Evaluation of Essential Oils Extracted from Five. Pena GA, da Costa Lopes AS, de Morais SHS, do Nascimento LD, Dos Santos FRR, da Costa KS, Alves CN, Lameira J. Molecules. Tunable Production of ( R)- or ( S)-Citronellal from Geraniol via a Enzymatic conversions in BY4741 culture and nonenzymatic conversions in medium without yeast inoculation from terpene alcohols. Cells were removed from medium by centrifugation at 4C, 1000g for 10 min. Disclaimer. 2022 Mar 23;13(4):317. doi: 10.3390/insects13040317. 8600 Rockville Pike Because it can ward off mosquitoes, it may also protect against mosquito-borne diseases, such as malaria, filariasis, chikungunya virus, yellow fever and dengue. We provide evidence that their biosynthesis mainly takes place in the cytosol of glandular trichomes via geranyl monophosphate (GP) through the action of a Nudix hydrolase. Interestingly, geraniol is also produced by honeybees to mark nectar-bearing flowers and to locate the entrances to their hives. The citronellols are also monoterpene alcohols; they are the hydrogenated forms of geraniol. Citronella has been registered asa gentle, plant-based bug spray ingredient in the U.S. since 1948. In this study, it has been demonstrated that geraniol and nerol can be converted to geranic acid, citronellic acid, and citronellol in the yeast metabolic pathway and to linalool nonenzymatically. Wiesenfeld M, Schimpfessel L, Crokaert R. Oxford University Press is a department of the University of Oxford. Wolff GH, Lahondre C, Vinauger C, Rylance E, Riffell JA. Let ACS help you navigate your career journey with tools, personal coaching and networking. When linalool was added to the medium without S. cerevisiae inoculation, geraniol was detected (Figure S2), suggesting nonenzymatic conversion of linalool to geraniol. This terp is more than a one-trick pony. You can naturally deodorize your home, dishwasher, refrigerator and laundry machine by diffusing citronella essential oil or running a cycle of your household appliances with a few drops of included. 92,93 The conversion of geraniol to its 10-hydroxy derivative represents an initial step in monoterpenoid indole alkaloid biosynthesis. 2020 Jan 1;71(1):258-271. doi: 10.1093/jxb/erz397. Promoting excellence in science education and outreach. Trap catches were significantly reduced again when diffusers were placed 3 m from the traps. The authors sincerely thank Dr. S. Jha (Professor, Department of Pharmaceutical Sciences, BIT, Mesra, Ranchi, Jharkhand, India) for identifying the flowering specimen. 2013) has been demonstrated in Saccharomyces cerevisiae under laboratory conditions, even though geraniol originates from plant materials. Citronella can contribute to natural stress relief when you diffuse it in your home or office to counteract a rough day. Plants (Basel). In fact, the most popular use for citronella is as an ingredient in homemade or commercially made bug sprays, since it naturally repels various insects and insect repellent is just one of citronellas many possible uses. 2013). Myrcene, citronellal and geraniol are all of similar size, so have similar dispersion forces.. Citronellal has a polar C=O group so can engage in dipole-dipole interactions so has a higher boiling point than myrcene. This article is based on scientific evidence, written by experts and fact checked by our trained editorial staff. Reactions: Chemistry Science Videos & Infographics Tinh du Bch n Chanh 10ml - DROPPII An official website of the United States government. Plants | Free Full-Text | Nanocapsules of ZnO Nanorods and Geraniol as But it also acts as an antimicrobial agent to destroy bacteria and fungi harmful to our health! Wany, A., Kumar, A., Nallapeta, S. et al. In another viewpoint, geranic acid has very unique characteristics that functions as an aromatic enhancer for hop-derived terpenoids at subthreshold levels (Sanekata, et al. Can citronella oil be applied to skin? On the other hand, growth and ethanol production were not decreased in the adh4 strain (Figure S4). Efficacy of the botanical repellents geraniol, linalool, and citronella Outdoors, citronella diffusers placed 6 m from mosquito traps repelled female mosquitoes by 22%, linalool repelled females by 58%, and geraniol repelled females by 75%. Thnh phn: Thnh phn chnh l Citronellal chim ti hn 70%. With these potent properties, is citronella oil harmful to humans? Sfa1p has 2 functions as a long-chain alcohol dehydrogenation enzyme and a formaldehyde dehydrogenation enzyme (Weimer, Rao and Brendel 1993). Helium (>99.99995%) was used as a carrier gas at a flow rate of 1.2 mL/min, and thermal conditions were set at 250C for a sample injection port and 230C for a MS ion source. You can also use citronella to keep your dogs off of furniture. Aside from keeping away bug bites, citronella can work as a natural skin care aid by killing off bacteria and fungus.