Terpinyl acetate

Inhibition of BACE1, MAO-B, cholinesterase enzymes, and anti-amyloidogenic potential of selected natural phytoconstituents: Multi-target-directed ligand approach.[Pubmed:33249607]

J Food Biochem. 2020 Nov 29:e13571.

Alzheimer's disease (AD) is a neurodegenerative disorder, and multiple factors are involved in disease progression. This is why there is an urgent need to develop novel molecules with multi-target-directed ligands (MTDLs) potential. The current study explores the active phytoconstituents from traditionally used medicinal spices, namely piperine, cinnamaldehyde, eugenol, cuminaldehyde, and alpha-Terpinyl acetate for the inhibition of beta-secretase, monoamine oxidase, cholinesterase enzymes, anti-aggregation of amyloid beta (Abeta) fibrils, and their protective effect against hydrogen peroxide (H2 O2 ) and Abeta-induced toxicity. Eugenol showed inhibitory activity against MAO-B enzyme, free radical scavenging activity, and anti-aggregation activity against Abeta peptides than other phytoconstituents. It also demonstrated a significant cytoprotective effect against H2 O2 -induced oxidative stress and Abeta-induced cytotoxicity in pheochromocytoma (PC) 12 cells. A molecular docking study of eugenol showed interactions with active site residue of the target enzymes. The study successfully demonstrated that eugenol could have an MTDLs potential better than synthesized drugs used in the treatment of AD. PRACTICAL APPLICATIONS: The present study demonstrated multi-target-directed ligand potential of eugenol and can be developed to treat complex diseases like Alzheimer's. Eugenol can bind to different Alzheimer's targets such as beta-secretase (BACE1), Monoamine oxidase B (MAO-B), Cholinesterase's, and amyloid beta1-42 fibrils and might have a disease-modifying potential. The other natural phytoconstituents such as piperine, cinnamaldehyde, cuminaldehyde, and alpha-Terpinyl acetate also demonstrated MTDL potential could also be used for developing novel molecules for disease-modifying effect. It also protects against oxidative stress.

Anti-Termitic Activity of Three Plant Extracts, Chlorpyrifos, and a Bioagent Compound (Protecto) against Termite Microcerotermes eugnathus Silvestri (Blattodea: Termitidae) in Egypt.[Pubmed:33158029]

Insects. 2020 Nov 4;11(11). pii: insects11110756.

A trend towards environmentally friendly chemicals for use in termite management has been occurring globally. This study examined three naturally occurring plant extracts from Lavandula latifolia (Spike lavender), Origanum vulgare (Marjorum), and Syzygium aromaticum (Clove) against the termite Microcerotermes eugnathus. Plant extract results were compared to two commercially used termite pesticides, the bio-insecticide, Bacillus thuringiensis var. kurstaki (Protecto 9.4% WP) and Dursban (Chlorpyrifos 48%). Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the main compounds in the three plant extracts. The main compounds in Lavandula Latifolia were linalool (21.49%), lavandulol (12.77%), beta-Terpinyl acetate (10.49%), and camphor (9.30%). Origanum vulgare extract contained thymol (14.64%), m-cymene (10.63%), linalool (6.75%), and terpinen-4-ol (6.92%) as main compounds. Syzygium aromaticum contained eugenol (99.16%) as the most abundant identified compound. The extract of O. vulgare caused the highest termite death rate, with an LC50 of 770.67 mg/L. Exposure to lavender extract showed a high death rate with an LC50 of 1086.39 mg/L. Clove extract did not show significant insecticidal activity with an LC50 > 2000 mg/L. Significant termiticide effects were found, with LC50 values of 84.09 and 269.98 mg/L for soldiers and workers under the application of Dursban and Protecto, respectively. The LC50 values reported for nymphs were <120, <164.5, and 627.87 mg/L after exposure to Dursban, Protecto, and O. vulgare extract, respectively. The results of the study show that some of the extracts have low toxicity compared to the bioagent and Dursban, and may show promise as natural termiticides, particularly as extracts from O. vulgare.

Identification of phytochemicals as potential therapeutic agents that binds to Nsp15 protein target of coronavirus (SARS-CoV-2) that are capable of inhibiting virus replication.[Pubmed:32943302]

Phytomedicine. 2020 Sep 3:153317.

BACKGROUND: Coronavirus disease 2019 (COVID-19) playing havoc across the globe caused 585,727 deaths and 13,616,593 confirmed cases so far as per World Health Organization data released till 17th July 2020. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) is responsible for causing this pandemic across different continents. It is not only impacting the world economy but also quarantined millions of people in their homes or hospitals. PURPOSE: At present, there is no Food and Drug Administration-approved drug or vaccine available to treat this disease. Still, people are trying various pre-existing medicines that are known to have anti-viral or anti-parasitic effects. In view of this, the present study aimed to study the binding potential of various phytochemicals present in multiple natural plant extract as a secondary metabolite to non-structural protein 15 (Nsp15) protein, a drug target known to play a crucial role in virulence of coronavirus. METHOD: Nsp15 protein was selected because it shows 89% similarity to the other SARS-CoV, which caused the earlier outbreak. The assumption is that inhibition of Nsp15 slowdowns the viral replication. Phytochemicals are selected as these are present in various plant parts (seed, flower, roots, etc.), which are used in different food cuisines in different geographical regions across the globe. The molecular docking approach was performed using two different software, i.e., Autodock, and Swissdock, to study the interaction of various phytochemicals with Nsp15 protein. Hydroxychloroquine is used as a positive control as it is used by medical professionals showing some positive effects in dealing with coronavirus. RESULTS: The present study demonstrated the binding potential of approximately 50 phytochemicals with Nsp15 and capable of inhibiting the viral replication, although in vitro and in vivo tests are required to confirm these findings. CONCLUSIONS: In conclusion, the present study successfully demonstrated the binding of phytochemicals such as sarsasapogenin, ursonic acid, curcumin, ajmalicine, novobiocin, silymarin and aranotin, piperine, gingerol, rosmarinic acid, and alpha Terpinyl acetate to Nsp15 viral protein and they might play a key role in inhibiting SARS-CoV-2 replication.

Antioxidant, DNA damage protective, antibacterial activities and nitrite scavenging ability of essential oil of Amomum kravanh from China.[Pubmed:32662302]

Nat Prod Res. 2020 Jul 14:1-5.

Chemical composition, in vitro antioxidant, DNA damage protective, nitrite scavenging activities, as well as antibacterial activity of Amomum kravanh fruits essential oil against several foodborne pathogens, were investigated. Results showed that the 1,8-cineole (58.53%) was found as the main component, followed by alpha-pinene (8.32%), alpha-Terpinyl acetate (4.68%), alpha-terpinolene (4.12%), alpha-terpinene (3.55%), beta-pinene (3.49%). The essential oil had significant antioxidant activity, the protective effect against DNA damage, and nitrite scavenging activity. These biological activities were dose-dependent, increasing with the higher dosage in a certain concentration range. The essential oil exhibited antibacterial activity against four foodborne pathogens with the minimum inhibitory concentration (MIC) of 5-10 mg/mL and minimum bactericide concentration (MBC) of 10-20 mg/mL. The antibacterial effects of essential oil were greater against Gram-positive bacteria as compared to Gram-negative bacteria. These results suggested that essential oil could be available as a significant natural agent for prevention of food oxidation and spoilage.

Improved Monitoring of Grapholita molesta (Lepidoptera: Tortricidae) in Stone Fruit Orchards with a Pheromone-Kairomone Combination Lure.[Pubmed:32635150]

Insects. 2020 Jul 3;11(7). pii: insects11070412.

Monitoring oriental fruit moth Grapholita molesta Busck (Lepidoptera: Tortricidae), populations based on counts in sex pheromone-baited traps within sex pheromone-treated orchards for mating disruption (MD) is challenging since male orientation to traps is disrupted. In this study, we evaluated a new commercial pheromone-kairomone combination lure for G. molesta (Pherocon((R)) OFM Combo Dual), which combines the G. molesta and Cydia pomonella L. sex pheromones with a blend of acetic acid and Terpinyl acetate. Trap comparisons were performed in 33 trials in peach and nectarine orchards under MD (24) or non-MD (9) during the 2018-2019 period in Italy. Male and total moth captures in traps baited with the combination lure were significantly greater than in traps with G. molesta pheromone in both years and across both pheromone treatments. The proportion of females in the total moth captures using the combination lure averaged ca. 7% across all trials. The by-catch of non-targets, i.e., Apis mellifera L., was low in traps baited either with the combination and the sex pheromone lure, while trap color (white) affected the capture of beneficials but not of the target pest. Our study proves that this combination lure can improve the monitoring and management for G. molesta in stone fruits. New studies are needed to define action thresholds to trigger supplemental control methods to MD. Secondly, female-based monitoring lures should be further developed to improve management strategies.

Chemical Diversity of Volatile Compounds of Mints from Southern Part of Pannonian Plain and Balkan Peninsula - New Data.[Pubmed:32469127]

Chem Biodivers. 2020 Aug;17(8):e2000211.

Mints are the most popular economic and traditional herbs. The aim of this article was chemical characterization of volatile compounds from wild populations of Mentha aquatica, M. arvensis, M. longifolia, M. microphylla, M. pulegium, M. spicata, M.xdumetorum, M.xgentillis and M.xverticillata, as well as cultivated samples of M. spicata, M.xpiperita 'Alba' and M.xpiperita 'Crispa'. Analyses were performed directly from dried aerial parts (herb) of collected samples by headspace gas chromatography-mass spectrometry. In total 54 compounds were detected, representing from 89.99 % to 99.66 % of volatile fractions of all investigated samples. The recorded volatiles were primarily monoterpene hydrocarbons and oxygenated monoterpenes, while oxygenated aromatic monoterpenes, sesquiterpene hydrocarbons and aliphatic compounds were present in lower concentrations in analyzed samples. The major components were linalool, limonene, 1,8-cineol, alpha-Terpinyl acetate, pulegone, beta-pinene and menthol. The cluster analysis revealed five main groups or chemotypes according to qualitative and quantitative content of volatiles, as well as similarities among samples. These results contribute to the knowledge on the mints chemistry in Pannonian Plain and Balkan Peninsula.

A Comparative Study of the in Vitro Antimicrobial and Synergistic Effect of Essential Oils from Laurus nobilis L. and Prunus armeniaca L. from Morocco with Antimicrobial Drugs: New Approach for Health Promoting Products.[Pubmed:32218155]

Antibiotics (Basel). 2020 Mar 25;9(4). pii: antibiotics9040140.

Laurus nobilis L. (laurel, Lauraceae) and Prunus armeniaca L. (apricot, Rosaceae) are important industrial crops and display significant biological properties, including antimicrobial activity. In this work, essential oils (EOs) prepared from the leaves of both species from Morocco were evaluated for the first time for possible synergistic in vitro antibacterial and antifungal effects with some conventional antimicrobial drugs, namely fluconazole, ciprofloxacin and vancomycin. Samples were further evaluated for chemical composition by gas chromatography-mass spectrometry (GC-MS). The main volatile compounds detected in L. nobilis were eucalyptol (40.85%), alpha-Terpinyl acetate (12.64%) and methyl eugenol (8.72%), while P. armeniaca was dominated essentially by (Z)-phytol (27.18%), pentacosane (15.11%), nonacosane (8.76%) and benzaldehyde (7.25%). Regarding antimicrobial activity, both EOs inhibited significantly all the microorganisms tested. The EO from L. nobilis had the highest activity, with minimal inhibitory concentrations (MICs) ranging from 1.39 to 22.2 mg/mL for bacteria and between 2.77 and 5.55 mg/mL for yeasts. Conversely, the combination of the studied EOs with ciprofloxacin, vancomycin and fluconazol resulted in a noteworthy decrease in their individual MICs. In fact, of the 32 interactions tested, 23 (71.87%) demonstrated total synergism and 9 (28.12%) a partial synergistic interaction. The EO from L. nobilis exhibited the highest synergistic effect with all the antibiotics used, with fractional inhibitory concentration (FIC) index values in the range of 0.266 to 0.75 for bacteria, and between 0.258 and 0.266 for yeast. The synergistic interaction between the studied EOs and standard antibiotics may constitute promising anti-infective agents useful for treating diseases induced by antibiotic-resistant pathogens.

Prediction of Terpenoid Toxicity Based on a Quantitative Structure-Activity Relationship Model.[Pubmed:31805724]

Foods. 2019 Dec 1;8(12). pii: foods8120628.

Terpenoids, including monoterpenoids (C10), norisoprenoids (C13), and sesquiterpenoids (C15), constitute a large group of plant-derived naturally occurring secondary metabolites with highly diverse chemical structures. A quantitative structure-activity relationship (QSAR) model to predict terpenoid toxicity and to evaluate the influence of their chemical structures was developed in this study by assessing in real time the toxicity of 27 terpenoid standards using the Gram-negative bioluminescent Vibrio fischeri. Under the test conditions, at a concentration of 1 microM, the terpenoids showed a toxicity level lower than 5%, with the exception of geraniol, citral, (S)-citronellal, geranic acid, (+/-)-alpha-Terpinyl acetate, and geranyl acetone. Moreover, the standards tested displayed a toxicity level higher than 30% at concentrations of 50-100 microM, with the exception of (+)-valencene, eucalyptol, (+)-borneol, guaiazulene, beta-caryophellene, and linalool oxide. Regarding the functional group, terpenoid toxicity was observed in the following order: alcohol > aldehyde ~ ketone > ester > hydrocarbons. The CODESSA software was employed to develop QSAR models based on the correlation of terpenoid toxicity and a pool of descriptors related to each chemical structure. The QSAR models, based on t-test values, showed that terpenoid toxicity was mainly attributed to geometric (e.g., asphericity) and electronic (e.g., maximum partial charge for a carbon (C) atom (Zefirov's partial charge (PC)) descriptors. Statistically, the most significant overall correlation was the four-parameter equation with a training coefficient and test coefficient correlation higher than 0.810 and 0.535, respectively, and a square coefficient of cross-validation (Q(2)) higher than 0.689. According to the obtained data, the QSAR models are suitable and rapid tools to predict terpenoid toxicity in a diversity of food products.

Potential of hydrocarbon and oxygenated monoterpenes against Culex pipiens larvae: Toxicity, biochemical, pharmacophore modeling and molecular docking studies.[Pubmed:31378352]

Pestic Biochem Physiol. 2019 Jul;158:156-165.

Culex pipiens is a main vector for Bancroftian filariasis, Rift Valley Fever and diseases caused by other viruses, leaving several peoples with disabilities. In recent years, plant derived compounds have received much attention as potential alternatives to synthetic chemicals due to their low toxicity to mammals and environmental persistence. Twenty-one monoterpenes from different chemical groups (hydrocarbons and oxygenated products) were evaluated against Culex pipiens larvae. In addition, in vivo biochemical studies including effects on acetylcholine esterase (AChE), acid and alkaline phosphatases (ACP and ALP), total adenosine triphosphatase (ATPase) and gamma-aminobutyric acid transaminase (GABA-T) were investigated. Furthermore, in silico studies including pharmacophore elucidation, ADMET analysis and molecular docking of these compounds were performed. Among all tested monoterpenes, hydrocarbons [p-cymene, (R)-(+)-limonene and (+)-alpha-pinene], acetates (cinnamyl acetate, citronellyl acetate, eugenyl acetate and Terpinyl acetate), alcohols [(+/-)-beta-citronellol and terpineol], aldehydes [citral and (1R)-(-)-myrtenal] and ketone [(R)-(+)-pulegone] exhibited the highest larval toxicity with LC50=14.88, 27.97, 26.13, 2.62, 3.81, 2.74, 21.65, 1.64, 21.70, 21.76, 1.68 and 1.90mg/L after 48h of exposure, respectively. The compounds proved a significant inhibition of all tested enzymes except total ATPase. The biochemical and molecular docking studies proved that AChE and GABA-T were the main targets for the tested monoterpenes.

Chemical composition and bioactivity of essential oils and Ethanolic extracts of Ocimum basilicum L. and Thymus algeriensis Boiss. & Reut. from the Algerian Saharan Atlas.[Pubmed:31227024]

BMC Complement Altern Med. 2019 Jun 21;19(1):146.

BACKGROUND: There is increasing interest in the pharmaceutical and food industries to substitute synthetic chemicals with naturally occurring compounds possessing bioactive properties. Plants are valuable sources of bioactive compounds. The present study investigates the chemical composition and antioxidant, antimicrobial, and anticancer activities of ethanolic extracts (EEs) and essential oils (EOs) from two species in the Lamiaceae family, Ocimum basilicum L. and Thymus algeriensis Boiss. & Reut., cultivated in the Algerian Saharan Atlas. METHODS: The total flavonoid contents of the plants' ethanolic extracts were determined by the aluminium chloride method, while the total phenols were determined using the Folin-Ciocalteu method. Essential oils were obtained by hydrodistillation of the aerial parts of the plants and were analysed by GC-MS. The free radical-scavenging ability and antioxidant potential of the plants' EEs and EOs were probed using the 2, 2-diphenyl-picrylhydrazyl radical-scavenging, ABTS radical-scavenging, ferric-reducing power and phosphomolybdenum assays. The antimicrobial activities were evaluated against several pathogens characteristic of gram-negative bacteria (three species), gram-positive bacteria (three species) and fungi (two species). The microdilution method was used to estimate the minimum inhibitory concentrations (MICs). The oils' anticancer potential against several cancer types was also studied using the MTT assay and reported as the toxic doses that resulted in a 50% reduction in cancer cell growth (LD50). RESULTS: Phenolic compounds in the EEs from both plants were analysed by HPLC and demonstrated a rich flavonoid content. Chemical analysis of the essential oil from Ocimum basilicum revealed 26 unique compounds, with linalool (52.1%) and linalyl acetate (19.1%) as the major compounds. A total of 29 compounds were identified in the essential oil from Thymus algeriensis, with alpha-Terpinyl acetate (47.4%), neryl acetate (9.6%), and alpha-pinene (6.8%) as the major compounds. The ethanolic extracts and essential oils from both plants exhibited moderate antioxidant activities and moderate to weak antimicrobial activities. Furthermore, anticancer activities against the examined human cancer cell lines were associated with only the EOs from both plants, with LD50 values ranging between 300 and 1000 mug/mL. CONCLUSION: The results suggest that the bioactive compounds found in the ethanolic extracts and essential oils from Ocimum basilicum and Thymus algeriensis, with diverse antioxidant, antimicrobial and anticancer activities, may have beneficial applications in nutraceutical and pharmaceutical technologies.

Chemical Composition and Antimicrobial Activity of Laurus nobilis L. Essential Oils from Bulgaria.[Pubmed:30813368]

Molecules. 2019 Feb 22;24(4). pii: molecules24040804.

Laurel, Laurus nobilis L. is an evergreen plant belonging to the Lauraceae family, native to Southern Europe and the Mediterranean area. This is the first report on the composition and bioactivity of laurel essential oil (EO) from Bulgaria. The oil yield was 0.78%, 0.80%, and 3.25% in the fruits, twigs, and leaves, respectively. The main constituents in the fruit EO were 1,8-cineole (33.3%), alpha-Terpinyl acetate (10.3%), alpha-pinene (11.0%), beta-elemene (7.5%), sabinene (6.3%), beta-phellandrene (5.2%), bornyl acetate (4.4%), and camphene (4.3%); those in the twig EO were 1,8-cineole (48.5%), alpha-Terpinyl acetate (13.1%), methyl eugenol (6.6%), beta-linalool (3.8%), beta-pinene (3.4%), sabinene (3.3%) and terpinene-4-ol (3.3%); and the ones in the leaf EO were 1,8-cineole (41.0%), alpha-Terpinyl acetate (14.4%), sabinene (8.8%), methyl eugenole (6.0%), beta-linalool (4.9%), and alpha-terpineol (3.1%). The antibacterial and antifungal properties of laurel EOs were examined according to the agar well diffusion method. The leaf EO showed antibacterial and antifungal activities against almost all strains of the microorganisms tested, whereas the twig EO was only able to inhibit Staphylococcus aureus. Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 8739 were the bacterial strains that showed the highest resistance to the laurel EO. The results can benefit the EO industry and biopesticide development.

Phytochemical variations among four distinct varieties of Indian cardamom Elettaria cardamomum (L.) Maton.[Pubmed:30663385]

Nat Prod Res. 2020 Jul;34(13):1919-1922.

Elettaria cardamomum (L.) Maton prestigiously called as Indian cardamom and is mostly cultivated in south India at higher altitudes ranging from 900 to 1400 msl. The chemical composition of dry capsules essential oil of the four distinct varieties was chemo-profiled by gas chromatography-mass spectrometry (GC-MS). Results revealed a higher concentration of major monoterpene 1, 8-Cineole ranging between 28.94% and 34.91% in PV 1 and PV 2 varieties respectively. Other monoterpenes like alpha-Pinene, Sabinene, Linalool, alpha-Terpineol and Nerol were present considerable quantities in all of the four cardamom varieties. Two sesquiterpenic constituents namely, c-Elemene and 1,6,10-dodecatrien-3-ol (Nerolidol) were identified in all varieties. Three ester constituents were also obtained in PV 1 in which alpha-Terpinyl acetate (26.68%) exhibited as a major ester constituent followed by Ocimenyl acetate (0.80%) and E5-Dodecenyl acetate (0.30%). This is the first published report on the phytochemical concentration of recent varieties of Indian cardamom.[Formula: see text].

Comparative analysis of oil composition and antibacterial activity of aerial parts of Terminalia arjuna (Roxb.).[Pubmed:30618269]

Nat Prod Res. 2020 May;34(9):1311-1314.

Volatile oil composition of leaves and fruits of Terminalia arjuna (Roxb.) was reported for the first time. Oils were extracted by microwave assisted hydrodistillation where yield of both oils were found to be 0.20% and their GC-MS analyses led to the identification of 65 and 48 constituents, respectively. Major constituents of leaves were carvacrol (11.17%), thymol (6.52%), alpha-Terpinyl acetate (5.92%) and anethole (5.13%) while that of fruits were (E)-isoeugenol (11.48%), furfural (8.25%), p-vinylguaiacol (6.8%) and p-ethylguaiacol (5.72%) that demonstrated a significant difference between composition of its aerial parts, however, 33 constituents were identical that showed similarity characteristics in quality of these oils. Both leaf and fruit oils were found active against pathogenic and drug-resistant microbes: E. coli, Methicillin-resistant S. aureus, P. aeruginosa, Total-drug-resistant P. aeruginosa and K. pneumoniae with MIC values of 0.32, 0.32, 0.64, 0.64, 2.56 mg/mL and 0.16, 0.16, 0.32, 0.64, 1.28 mg/mL, respectively.