Biological effects of essential oils - A review

With digital equipment becoming increasingly networked, either on wired or wireless networks, for personal and professional use alike, distributed software systems have become a crucial element in information and communications technologies. The study of these systems forms the core of the ARLES' work, which is specifically concerned with defining new system software architectures, based on the use of emerging networking technologies. In this context, we concentrate on the study of distributed systems which bring to life the vision of ubiquitous computing systems, also known as ambient intelligence.

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Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review

While use of synthetic antioxidants (such as butylated hydroxytoluene and butylated hydroxyanisole) to maintain the quality of ready-to-eat food products has become commonplace, consumer concern regarding their safety has motivated the food industry to seek natural alternatives. Phenolic antioxidants can inhibit free radical formation and/or interrupt propagation of autoxidation. Fat-soluble vitamin E (α-tocopherol) and water-soluble vitamin C (L-ascorbic acid) are both effective in the appropriate matrix. Plant extracts, generally used for their flavoring characteristics, often have strong H-donating activity thus making them extremely effective antioxidants. This antioxidant activity is most often due to phenolic acids (gallic, protocatechuic, caffeic, and rosmarinic acids), phenolic diterpenes (carnosol, carnosic acid, rosmanol, and rosmadial), flavonoids (quercetin, catechin, naringenin, and kaempferol), and volatile oils (eugenol, carvacrol, thymol, and menthol). Some plant pigments (anthocyanin and anthocyanidin) can chelate metals and donate H to oxygen radicals thus slowing oxidation via 2 mechanisms. Tea and extracts of grape seeds and skins contain catechins, epicatechins, phenolic acids, proanthocyanidins, and resveratrol, all of which contribute to their antioxidative activity. The objective of this article is to provide an overview of natural antioxidants, their mechanisms of action, and potential applications.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1541-4337.2011.00156.x

Natural antioxidants: sources, compounds, mechanisms of action, and potential applications

Total equivalent antioxidant capacity (TEAC) and phenolic content of 26 common spice extracts from 12 botanical families were investigated. Qualitative and quantitative analyses of major phenolics in the spice extracts were systematically conducted by reversed-phase high-performance liquid chromatography (RP-HPLC). Many spices contained high levels of phenolics and demonstrated high antioxidant capacity. Wide variation in TEAC values (0.55−168.7 mmol/100 g) and total phenolic content (0.04−14.38 g of gallic acid equivalent/100 g) was observed. A highly positive linear relationship (R2 = 0.95) obtained between TEAC values and total phenolic content showed that phenolic compounds in the tested spices contributed significantly to their antioxidant capacity. Major types of phenolic constituents identified in the spice extracts were phenolic acids, phenolic diterpenes, flavonoids, and volatile oils (e.g., aromatic compounds). Rosmarinic acid was the dominant phenolic compound in the six spices of the family La...

Antioxidant Capacity of 26 Spice Extracts and Characterization of Their Phenolic Constituents

The volatile constituents of the leaf and root oils of Croton hieronymi Griseb. were studied by GC and GC/MS. Thirty-three and 32 compounds have been identified in leaf (60.2%) and root (86.2%) oils, respectively. The major components of the leaf oil were camphor (13.9%) and borneol (5.9%), whereas the root oil contained γ-asarone (25.7%), borneol (19.0%), (E)-asarone (11.4%) and camphor (11.1%) as main constituents. The oils were tested for their inhibitory effect against four strains of bacteria (Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae and Streptococcus pyogenes) and one yeast (Candida albicans). The root oil was found to be active against E. coli and C. albicans, moderately effective against K. pneumoniae and showed little or no activity against S. typhimurium and S. pyogenes. The leaf oil was active against K. pneumoniae and moderately active against E. coli.

César A.N. Catalán

Papers

Antimicrobial Activity and Chemical Composition of the Leaf and Root Oils from Croton hieronymi Griseb

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