Spectrophotometric Investigations of Monohydroxylic Flavylium Compounds

Monohydroxylic flavylium compounds in positions C-7 or C-4’ were investigated in buffer solutions of pH 2.00-8.50. The direction of structural transformations of these compounds, which was absorptiometrically followed, was correlated to the influence of substituted positions. Transformation processes were quantitatively defined by the corresponding pK values

War Injuries of Colon and Rectum – Results After 10 Years

The aim of our study is to evaluate results of treating war injuries of colon and rectum, after 10 years. During the war in Croatia, 21 wounded, with colon (19) and rectum (2) injuries, were treated in the Department of Surgery at Nova Gradi{ka General Hospital from August 1991 to April 1992. Bullet wounds accounted for 57% of the injuries. All patients had other associated injuries. Primary repair and proximal derivation was possible in 2 cases (9.5%), while primary resection with intraperitoneal anastomosis was performed in 3 (14.3%) patients. In 2 (9.5%) patients sustained intraperitoneal and extraperitoneal rectal penetrating injury rectum was resected and closed performing temporary sigmoidostomy. When multiple perforations or crush injury of the colon were found, in 8 (38.1%) injured persons resection of the involved segment was combined with proximal end colostomy and aboral mucous fistula. Exteriorization of injured segment of the colon and creating colostomy incorporating the injured colon as the stoma was performed in 6 (28.5%) wounded patients. Four of the wounded (19.0 %) died two of them during the operative procedure due to hemorrhagic shock. One injured died after eight days due to pulmonary embolism, and one patient died after thirty days due to sepsis. Reoperation was necessary in two (9.5%) injured due to bowel obstruction four days following initial surgery because of adhesions. Three (14.3%) of the injured had wound infection, one of them died 30 days after injury due to sepsis, and two (9.5%) consequently developed ventral hernia that was operated after 4 and 5 years respectively. Four (19.0%) of the injured are still occasionally experiencing occasional abdominal pain

Flavonoids in prevention of diseases with respect to modulation of Ca-pump function

Flavonoids, natural phenolic compounds, are known as agents with strong antioxidant properties. In many diseases associated with oxidative/nitrosative stress and aging they provide multiple biological health benefits. Ca2+-ATPases belong to the main calcium regulating proteins involved in the balance of calcium homeostasis, which is impaired in oxidative/nitrosative stress and related diseases or aging. The mechanisms of Ca2+-ATPases dysfunction are discussed, focusing on cystein oxidation and tyrosine nitration. Flavonoids act not only as antioxidants but are also able to bind directly to Ca2+-ATPases, thus changing their conformation, which results in modulation of enzyme activity

Natural flavonoids as potential multifunctional agents in prevention of diabetic cataract

Cataract is one of the earliest secondary complications of diabetes mellitus. The lens is a closed system with limited capability to repair or regenerate itself. Current evidence supports the view that cataractogenesis is a multifactorial process. Mechanisms related to glucose toxicity, namely oxidative stress, processes of non-enzymatic glycation and enhanced polyol pathway significantly contribute to the development of eye lens opacity under conditions of diabetes. There is an urgent need for inexpensive, non-surgical approaches to the treatment of cataract. Recently, considerable attention has been devoted to the search for phytochemical therapeutics. Several pharmacological actions of natural flavonoids may operate in the prevention of cataract since flavonoids are capable of affecting multiple mechanisms or etiological factors responsible for the development of diabetic cataract. In the present paper, natural flavonoids are reviewed as potential agents that could reduce the risk of cataract formation via affecting multiple pathways pertinent to eye lens opacification. In addition, the bioavailability of flavonoids for the lens is considered

Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits

Anthocyanins are colored water-soluble pigments belonging to the phenolic group. The pigments are in glycosylated forms. Anthocyanins responsible for the colors, red, purple, and blue, are in fruits and vegetables. Berries, currants, grapes, and some tropical fruits have high anthocyanins content. Red to purplish blue-colored leafy vegetables, grains, roots, and tubers are the edible vegetables that contain a high level of anthocyanins. Among the anthocyanin pigments, cyanidin-3-glucoside is the major anthocyanin found in most of the plants. The colored anthocyanin pigments have been traditionally used as a natural food colorant. The color and stability of these pigments are influenced by pH, light, temperature, and structure. In acidic condition, anthocyanins appear as red but turn blue when the pH increases. Chromatography has been largely applied in extraction, separation, and quantification of anthocyanins. Besides the use of anthocyanidins and anthocyanins as natural dyes, these colored pigments are potential pharmaceutical ingredients that give various beneficial health effects. Scientific studies, such as cell culture studies, animal models, and human clinical trials, show that anthocyanidins and anthocyanins possess antioxidative and antimicrobial activities, improve visual and neurological health, and protect against various non-communicable diseases. These studies confer the health effects of anthocyanidins and anthocyanins, which are due to their potent antioxidant properties. Different mechanisms and pathways are involved in the protective effects, including free-radical scavenging pathway, cyclooxygenase pathway, mitogen-activated protein kinase pathway, and inflammatory cytokines signaling. Therefore, this review focuses on the role of anthocyanidins and anthocyanins as natural food colorants and their nutraceutical properties for health. Abbreviations: CVD: Cardiovascular disease VEGF: Vascular endothelial growth factor

Radical Scavenging Activity and Pharmacokinetic Properties of Coumarin–Hydroxybenzohydrazide Hybrids

Free radicals often interact with vital proteins, violating their structure and inhibiting their activity. In previous studies, synthesis, characterisation, and the antioxidative properties of the five different coumarin derivatives have been investigated. In the tests of potential toxicity, all compounds exhibited low toxicity with significant antioxidative potential at the same time. In this paper, the radical scavenging activity of the abovementioned coumarin derivatives towards ten different radical species was investigated. It was found that all investigated compounds show good radical scavenging ability, with results that are in correlation with the results published in the previous study. Three additional mechanisms of radical scavenging activity were investigated. It was found that all three mechanisms are thermodynamically plausible and in competition. Interestingly, it was found that products of the Double Hydrogen Atom Transfer (DHAT) mechanism, a biradical species in triplet spin state, are in some cases more stable than singlet spin state analogues. This unexpected trend can be explained by spin delocalisation over the hydrazide bridge and phenolic part of the molecule with a low probability of spin pairing. Besides radical-scavenging activity, the pharmacokinetic and drug-likeness of the coumarin hybrids were investigated. It was found that they exhibit good membrane and skin permeability and potential interactions with P-450 enzymes. Furthermore, it was found that investigated compounds satisfy all criteria of the drug-likeness tests, suggesting they possess a good preference for being used as potential drugs.</jats:p

QSAR of the free radical scavenging potency of selected hydroxyanthraquinones

© 2018, Institute of Chemistry, Slovak Academy of Sciences. It is well known that anthraquinones are molecules with moderate, but not negligible antioxidative activity. Their chemical behaviour is influenced by different parameters such as thermodynamics, orbital and structural properties, and polarity of environment. To find dependence of antioxidant activity of fourteen selected anthraquinones on the physicochemical parameters, we developed one-, two- and three-descriptor mathematical models. In all quantitative structure–activity relationship models (QSAR), experimentally obtained ABTS values were used as dependent variables. One-descriptor model indicated that in methanol the best correlation give enthalpies that describe stable radical formation following single proton loss, and then transfer of electron. Unexpectedly, the best two-descriptor model shows the best dependence of the experimental results on the combination of the orbital and structural parameters. The best two-parameter model was improved by introducing one thermodynamical parameter, such as bond dissociation enthalpy. On that way the best three-descriptor model was obtained. It indicates that the best insight into the antioxidant capacity of a molecule can be obtained by pooling all types of parameters and influences in a mathematical model