Seasonal variation of volatile oil composition and antioxidant property of aerial parts of Syzygium paniculatum Gaertn. grown in the Eastern Cape,South Africa

Syzygium paniculatum Gaertn of the family Myrtaceae is a medicinal and aromatic plant. The hydrodistilled volatile oil (VO) from the aerial parts was characterised by GC-MS and Kovat’s index, while the antioxidant property was investigated using spectrophotometric techniques. Antioxidant capacities of the aerial parts VOs range from 0.12 to 0.93?mg/mL in scavenging 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH^?). Overall, 75 and 67 compounds were identified from the summer and winter VOs, respectively. The main compounds were α-pinene (33.13%), n-hexadecanoic acid (19.14%), limonene (14.26%), farnesol (14.21%), β-ocimene (13.04%), citronellol (12.67%), linoleic acid (11.50%), octahydro-1,4-dimethyl azulene (11.57%), citral (9.91%), phytol (5.07%), linolenic acid (4.85%) and thymol (2.23%). The bioavailability of citronellol, thymol, β-ocimene and linoleic acid, used as bactericidal, fungicidal and antioxidant agents in cosmetics and perfumery, suggests S. paniculatum potential as a natural food flavouring and source of antibiotics in this era of emerging multi-drug-resistant pathogens.     

Alcoholic monoterpenes found in essential oil of aromatic spices reduce allergic inflammation by the modulation of inflammatory cytokines

Allergic inflammation is a response of the body against pathogens by cytokine release and leucocyte recruitment. Recently, there was an increase in morbimortality associated with allergic inflammation, especially asthma. The treatment has many adverse effects, requiring the search for new therapies. Monoterpenes are natural products with anti-inflammatory activity demonstrated in several studies and can be an option to inflammation management. Thus, we investigated the effects of citronellol, α-terpineol and carvacrol on allergic inflammation. The model of asthma was established by OVA induction in male Swiss mice. The monoterpenes were administered (25, 50 or 100 mg/kg, i.p.) 1 h before induction. After 24hs, the animals were sacrificed to leucocytes and TNF-α quantification. Monoterpenes significantly decrease leucocyte migration and TNF-α levels, possibly by modulation of COX, PGE₂ and H1 receptor, as demonstrated by molecular docking. These findings indicate that alcoholic monoterpenes can be an alternative for treatment of allergic inflammation and asthma.     

Citronellol-Based Long-Lasting Antibacterial Cotton Fabrics without Bacterial Resistance

Antibacterial cotton helps prevent the growth and spread of harmful microorganisms, reduces the risk of infection, and has a prolonged service life by reducing bacterial degradation. However, most antibacterial agents used are toxic to humans and the environment. Citronellol-poly(N,N-dimethyl ethyl methacrylate) (CD), a highly effective antibacterial polymer, is synthesized from natural herbal essential oils (EOs). CD exhibited efficient, rapid bactericidal activity against Gram-positive, Gram-negative, and drug-resistant bacteria. Citronellol's environmental benignity makes CDs less hemolytic. Notably, negligible drug resistance developed after 15 bacterial subcultures. The CD-treated cotton fabric displayed better antibacterial performance than AAA-grade antibacterial fabric, even after repeated washing. This study extends the practical application of EOs to antibacterial surfaces and fabrics, which is promising for use in personal care products and medical settings.     

光学活性松干蚧性信息素C-8-C-13片断的合成

本文报道了从(S)-香茅醇合成化合物(2R)-3,5-dimethyl-hexan-1-o1(9), 即光学活性日本松干蚧性信息素C-8-C13片断, 共经九步反应, 总产率为57%。     

Transfer hydrogenation of citral to citronellol with Ru complexes in the mixed solvent of water and polyethylene glycol

The transfer hydrogenation of citral to citronellol was studied with [RuCl₂(benzene)]₂ catalyst in a mixed solvent of water and polyethylene glycol (H₂O? PEG). The influence of several important factors including hydrogen source, solvent, temperature and active species is discussed. Under the present conditions, citronellol was produced with an extremely high selectivity above 90%. The Ru complexes could be immobilized in the H₂O? PEG phase well and separated from organic products successfully. Moreover, a stable catalytic activity was obtained after the first run, although the decomposition of Ru complexes occurred during the recycling processes. The selectivity to citronellol decreased but kept a stable level about 60% in the recycling runs. Copyright © 2010 John Wiley & Sons, Ltd.     

Rose Oxides: A Facile Chemo and Chemo‐Enzymatic Approach

Nonracemic rose oxides were synthesized from racemic or nonracemic monoterpene alcohol citronellol by a novel chemo and chemo‐enzymatic route. After the key step of bromomethoxylation of citronellol, the intermediate was dehydrobrominated by a base, followed by an acid catalyzed demethoxylation along with cyclization to furnish rose oxides in high yield. The racemic dehydrobrominated precursor was also kinetically resolved using various lipases to produce nonracemic rose oxides.     

Photo-induced catalytic partial oxidation of citronellol with assistance of phthalocyanines

Attention was paid to the role of sulfonated phthalocyanines as efficient photocatalysts in the photo-induced partial oxidation of citronellol. Performance of the singlet oxygen species inducing the formation of citronellol hydroperoxides was studied in detail. The involved reactions may be of great importance in the catalytic production of rose oxide — a highly appreciated component of many synthetic fragrances.     

Electrochemical hydrogenation of citral

The factors (concentration of citral, composition of the solvent, AcOH citral ratio) affecting electrochemical hydrogenation of citral at an annealed copper cathode have been determined. The highest total yield (94 %) of the alcohols (nerol, geraniol, citronellol) with a considerable predominance of the latter is achieved at 40 % DMF in water, citral concentration 0.02M, and AcOH citral ratio=101. The transition to purely organic or purely aqueous media leads to a decrease in both the total yield of the alcohols and the selectivity of the process.For Part 1, see Ref. lTranslated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1919–1923, November, 1993.