ABSTRACT
Abstract Alzheimer's disease (AD) is a neurological disorder in which the neuronal degeneration is associated with inflammatory processes and oxidative stress. Since alpha-terpineol was shown to possess antioxidant and anti-inflammatory effects, the administration of this compound was studied on a rat model of AD. To create this model, Aβ1-42 was injected into the hippocampus of male Wistar rats. Generated AD models were divided into simple AD models and AD models in which short-term immobilization stress was added. Preventive and therapeutic (post-AD induction) effects of alpha-terpineol consumption (100 mg/Kg) were subsequently investigated in AD models, which were compared with control groups. Biochemical factors (superoxide dismutase and malondialdehyde), histological manifestations (amyloid plaques and neuron counts) and possible memory impairment (shuttle-box experiment) were investigated in all groups. For the in vitro experiment, alpha-terpineol effect was checked on Aβ1-42 fibril formation. In preventive and therapeutic modes, alpha-terpineol consumption could improve neurogenesis and long-term memory while reducing amyloid plaque counts and ameliorating biochemical factors (higher levels of superoxide dismutase and malondialdehyde and reduced levels of MDA). In vitro, shorter fibrillar structures were formed in the presence of alpha-terpineol, which indicates an anti-amyloid effect for this compound. In conclusion, alpha-terpineol significantly counteracted AD consequences.
ABSTRACT
Objective:The volatile components of Rhododendri Mollis Flos were determined and the differences of volatile components at different flowering stages were compared and analyzed. Method:Gas chromatography-ion mobility spectrometry （GC-IMS） was used to detect the volatile components in Rhododendri Mollis Flos at different flowering stages （bud stage， initial flowering stage， half-flowering stage， blooming stage and late blooming stage）. GC-IMS spectra combined with cluster analysis， principal component analysis （PCA） and orthogonal partial least squares-discriminant analysis （OPLS-DA） were used to compare the differences and similarities of volatile components in different flowering stages. Result:A total of 70 volatile components in Rhododendri Mollis Flos at different flowering stages were detected， among which 67 were common components， and 47 were identified qualitatively， mainly alcohols， esters and aldehydes. Carveol was a special component at the late blooming stage. The content of alpha-terpineol is the highest at the initial flowering stage， but not at the blooming stage and late blooming stage. The relative contents of the active ingredients ［6-methyl-5-hepten-2-one， nonanal， alpha-terpineol， 1，8-cineole， linalool oxide， 1-octen-3-ol， （<italic>E</italic>）-3-hexenol］ showed a decreasing trend during flowering stages. GC-IMS spectra showed that the samples at different flowering stages had their own characteristic peak regions， and also had common regions. The results of cluster analysis， PCA and OPLS-DA all showed that the samples at different flowering stages were distinguishable. OPLS-DA was used to screen 19 different components to distinguish different flowering stages， including <italic>γ</italic>-butyrolactone， 1，8-cineole， ethyl hexanoate， etc. Conclusion:Rhododendri Mollis Flos samples at different flowering stages can be distinguished obviously， and the active substances in the volatile components are gradually dissipated with the degree of flower opening， which can provide reference for the improvement of material basis and the study of different flowering stages of Rhododendri Mollis Flos.
ABSTRACT
Two white rot fungi, Ceriporia sp. ZLY-2010 (CER) and Stereum hirsutum (STH) were used as biocatalysts for the biotransformation of (-)-alpha-pinene. After 96 hr, CER converted the bicyclic monoterpene hydrocarbon (-)-alpha-pinene into alpha-terpineol (yield, 0.05 g/L), a monocyclic monoterpene alcohol, in addition to, other minor products. Using STH, verbenone was identified as the major biotransformed product, and minor products were myrtenol, camphor, and isopinocarveol. We did not observe any inhibitory effects of substrate or transformed products on mycelial growth of the fungi. The activities of fungal manganese-dependent peroxidase and laccase were monitored for 15 days to determine the enzymatic pathways related to the biotransformation of (-)-alpha-pinene. We concluded that a complex of enzymes, including intra- and extracellular enzymes, were involved in terpenoid biotransformation by white rot fungi.
Subject(s)
Biotransformation , Camphor , Enzymes , Fungi , Laccase , PeroxidaseABSTRACT
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important causative microbes for nosocomial infection and has been isolated from the dental environment. The purpose of this study was to investigate the antimicrobial activity of linalool and alpha-terpineol against MRSA isolates from a Korean population. In the experiments, we determined the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these two compounds against 18 strains of MRSA. The data revealed that the MIC90/MBC90 values of linalool and alpha-terpineol against MRSA were >12.8 mg/ml and 6.4 mg/ml, respectively. These results indicate that alpha-terpineol has more potent antimicrobial activity against MRSA than linalool and may have utility as an anti-MRSA cleansing agent for dental instruments and dental unit chairs.