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 most widely used spectroscopic methods for the identification of sesquiterpene lactones are discussed. The most distinctive and characteristic signals in the UV, IR, MS, 1H-MNR and 13C-NMR spectra are discussed. In addition, some examples of the application of these techniques for the structure elucidation of some representative sesquiterpene lactones with different skeletal types are presented.

Spectroscopic Methods for the Identification of Sesquiterpene Lactones

The aerial parts of Cyclolepis genistoides, commonly called “palo azul” or “matorro negro”, are widely used in folk medicine in Paraguay, Northern and central Argentina, as a diuretic and for the treatment of kidney diseases, urinary tract irritation, kidney pain, bone pain (analgesic). It is also used as an antipyretic, as a blood purifier, against liver diseases and as a hypotensive. The main metabolites identified in the chloroform extract of aerial parts are oleanolic, ursolic and betulinic acids and other closely related triterpenes along with the sesquiterpene lactones deacylcynaropicrin and its 11,13-dihydroderivative. Most of the uses of this plant could be justified by the known biological effects of above metabolites. Very little is known about the water-soluble metabolites of “palo azul”, and as such, research on the content of polyphenols, flavonoid glycosides, chlorogenic acid, dicaffeoylquinic acids and phenyletanoids are welcome.

Cyclolepis genistoides D. Don

Antiprotozoal compounds from Mikania periplocifolia.

The investigation of an Argentine collection of Enydra anagallis afforded sesquiterpene lactones of the melampolide type two of which were previously known. Their structures were elucidated by spectroscopic methods.

César A.N. Catalán

Papers

Spectroscopic Methods for the Identification of Sesquiterpene Lactones

Cyclolepis genistoides D. Don

Antiprotozoal compounds from Mikania periplocifolia.

Melampolides from Enydra anagallis

Trace Constituents of Lippia integrifolia.