Metabolism of Terpenoids in Animal Models and Humans
K. Hüsnü Can Başer, Gerhard Buchbauer in Handbook of Essential Oils, 2020
α-Terpineol, a monocyclic monoterpene alcohol, is found in the essential oil sources such as neroli, petitgrain, Melaleuca alternifolia, and Origanum vulgare (Bornscheuer et al., 2014). Based on its pleasant lilac-like odor, α-terpineol is widely used in the manufacture of perfumes, cosmetics, soaps, and antiseptic agents. After oral administration to rats (600 mg/kg body weight), α-terpineol is metabolized to p-menthane-1,2,8-triol, probably formed from the epoxide intermediate. Notably, allylic methyl oxidation and the reduction of the 1,2-double bond are the major routes for the biotransformation of α-terpineol in rat (Figure 10.24). Although allylic oxidation of C-1 methyl seems to be the major pathway, the alcohol p-ment-1-ene-7,8-diol could not be isolated from the urine samples. Probably, this compound is accumulated and is readily further oxidized to oleuropeic acid (Madyastha and Srivatsan, 1988a).
Herbal Product Development and Characteristics
Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam in Herbal Product Development, 2020
Controversial information is found about the compounds responsible for preventive action of Origanum genus against neurodegenerative diseases. Some authors affirm that thymol and carvacrol are the main active components (Loizzo et al., 2009), while others attributed main activity to terpenoids (4-terpinenol γ-terpinene, α-terpinene, p-cymene and 1,8-cineol) (Mossa and Nawwar, 2011). Recent studies combined both ideas, suggesting that these effects might be due to mixture of compounds present in the extracts or essential oils from this genus (Loizzo et al., 2009). Somewhat similar is documented for antibacterial activity, mentioning a synergistic effects of terpenoids such as carvacrol, linalool, thymol, γ-terpinene, p-cymene, and 4-terpineol (Burt, 2004).
Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Anton C. de Groot in Monographs in Contact Allergy, 2021
In 1988, in the USA, 400 perfumes used in fine fragrances, household products and soaps (number of products per category not mentioned) were analyzed for the presence of fragrance chemicals in a concentration of at least 1% and a list of the Top-25 (present in the highest number of products) presented. ‘Terpineol’ was found to be present in 66% of the fine fragrances (rank number 7), 66% of the household product fragrances (rank number 2) and 62% of the fragrances used in soaps (rank number 9) (2).
Chemical composition and insecticidal activities of the essential oils and various extracts of two Thymus species: Thymus cariensis and Thymus cilicicus
Published in Toxin Reviews, 2021
Selçuk Küçükaydın, Gülsen Tel-Çayan, Mehmet Emin Duru, Memiş Kesdek, Mehmet Öztürk
Thymus cariensis is endemic and growing naturally in Turkey. According to our literature survey, there is only one chemical report on its essential oil (Baser et al.1992). Thymus cilicicus is endemic to Turkey, Syria, and East Aegean Islands (Gürdal and Kültür 2013). Essential oil compositions of T. cilicicus have been previously reported, and α-terpineol (16.4%) and camphor (9.7%) were found as major compounds (Akgül et al.1999). In addition to that, antimicrobial activity by using the disc diffusion method (Sarac and Ugur 2008) and antioxidant activity with DPPH free radical scavenging method of essential oil of T. cilicicus have been investigated before (Azaz and Celen 2012). Ahmed and Al-Howiriny (2007) have been isolated two new chalcone derivatives from aerial parts of T. cilicicus.
Anti-Demodex Effect of Commercial Eyelid Hygiene Products
Published in Seminars in Ophthalmology, 2021
When examining similar studies on this subject, the study of Tighe et al.13 draws attention. In this study, T4O was found to be the strongest component in TTO, followed by a-terpineol, 1,8-cineole, and sabinene. Moreover, T4O was found to be more effective than TTO at equivalent concentrations. The killing effect of T4O was observed even at a concentration of only 1%. It was found to have a significant synergistic effect with Terpinolene, but an antagonistic effect was observed with α-terpineol. This study also emphasized that using T4O alone in Demodex treatment is more effective in preventing antagonistic effects than other substances in the TTO content. In fact, the most important point that draws our attention in this study is that when the concentration of all active substances including TTO, except T4O, falls below 10%, Demodex killing time goes up to 150 min or more. In order to reduce both cost and potential toxic effects, eye cleaning wipes and solutions available in the market contain active ingredients at a concentration below 10%. Thus, it is highly doubtful how much anti-Demodex activity will be for those with ingredients other than T4O. Our study highly supports this situation.
Exploring the antibacterial, antibiofilm, and antivirulence activities of tea tree oil-containing nanoemulsion against carbapenem-resistant Serratia marcescens associated infections
Published in Biofouling, 2022
Shatabdi Das, Kumari Vishakha, Satarupa Banerjee, Debasish Nag, Arnab Ganguli
ROS generation and membrane damage may not be the only antibacterial and anti-biofilm mechanisms of action for TTO-NE. Therefore, in silico analyses were performed to explore other mechanisms for the antibacterial and anti-biofilm effects of TTO against CRE-S. marcescens. Six essential proteins of CRE-S. marcescens (i.e. fimA, flhC, flhD, bsmA, bsmB, and ompA) were used as targets. Different components of TTO have been used as ligands. These are terpinen-4-ol, γ-terpinene, α-terpinene, terpinolene, 1,8-cineole, and α-terpineol (Shi et al. 2018). This in silico study revealed that all TTO components bound to all six target proteins (Figure 5B) and that all binding energies were greater than –4 (Table 1). Among all the chemical components of TTO, 1,8-cineole had the greatest interactions with all six proteins, as demonstrated by the binding energy calculation. These interactions between 1,8-cineole and six target proteins were mainly stabilized by non-covalent interactions. The highest binding energy of 1,8-cineole with fimA was −7.9 kcal mol−1.
Related Knowledge Centers
- Alcohol
- Cardamom
- Functional Group
- Pine Oil
- Monoterpene
- Cajeput Oil
- Petitgrain
- Terpinen-4-Ol
- Odor
- Scutellaria Barbata