“…The above molecular descriptor values obtained from the total energy method for the investigated compound are displayed in Table 1. The calculated molecular properties clearly confirms that quercetin and its glucosides prefer to act as electron donor rather than electron acceptor in the studied environments 16, 17 . This is also an indication of their antioxidant activity.Figure 1The chemical structure and atom numbering for quercetin and its glucosides.
…”
Among the multiple components of propolis, flavonoids contribute greatly to the antioxidant activities of propolis. Flavonoids mainly exist in the form of sugar-conjugated derivatives. Quercetin glycosides represent the predominant flavonoid fraction in propolis. In this work, density functional theory (DFT) calculations were applied to analyze the antioxidative properties of quercetin and its glucosides in the gas and in the liquid phase (ethanol, water). Three main antioxidant mechanisms, hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) were used to analyze the antioxidative capacity of the investigated compounds. Solvent effects dominantly affect SET-PT and SPLET. Thus, the thermodynamically preferred mechanism can be altered. HAT and SPLET are the thermodynamically dominant mechanisms in gas and solvent phases, respectively. Therefore, in the gas phase, the sequence of the antioxidative capacity is similar with the bond dissociation enthalpy values: quercetin > quercetin-5-O-glucoside > quercetin-7-O-glucoside > quercetin-3-O-glucoside > quercetin-3′-O-glucoside > quercetin-4′-O-glucoside. While, in the solvent phases, the sequence is similar with the proton affinity values: quercetin-4′-O-glucoside > quercetin-5-O-glucoside > quercetin > quercetin-3-O-glucoside > quercetin-7-O-glucoside > quercetin-3′-O-glucoside. OH groups in B-ring and C-ring contribute mainly to the antioxidative activities of quercetin and glucosides compared with A-ring.
“…The above molecular descriptor values obtained from the total energy method for the investigated compound are displayed in Table 1. The calculated molecular properties clearly confirms that quercetin and its glucosides prefer to act as electron donor rather than electron acceptor in the studied environments 16, 17 . This is also an indication of their antioxidant activity.Figure 1The chemical structure and atom numbering for quercetin and its glucosides.
…”
Among the multiple components of propolis, flavonoids contribute greatly to the antioxidant activities of propolis. Flavonoids mainly exist in the form of sugar-conjugated derivatives. Quercetin glycosides represent the predominant flavonoid fraction in propolis. In this work, density functional theory (DFT) calculations were applied to analyze the antioxidative properties of quercetin and its glucosides in the gas and in the liquid phase (ethanol, water). Three main antioxidant mechanisms, hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) were used to analyze the antioxidative capacity of the investigated compounds. Solvent effects dominantly affect SET-PT and SPLET. Thus, the thermodynamically preferred mechanism can be altered. HAT and SPLET are the thermodynamically dominant mechanisms in gas and solvent phases, respectively. Therefore, in the gas phase, the sequence of the antioxidative capacity is similar with the bond dissociation enthalpy values: quercetin > quercetin-5-O-glucoside > quercetin-7-O-glucoside > quercetin-3-O-glucoside > quercetin-3′-O-glucoside > quercetin-4′-O-glucoside. While, in the solvent phases, the sequence is similar with the proton affinity values: quercetin-4′-O-glucoside > quercetin-5-O-glucoside > quercetin > quercetin-3-O-glucoside > quercetin-7-O-glucoside > quercetin-3′-O-glucoside. OH groups in B-ring and C-ring contribute mainly to the antioxidative activities of quercetin and glucosides compared with A-ring.
15-lipo-oxygenases are one of the iron-containing proteins capable of performing peroxidation of unsaturated fatty acids in animals and plants. The critical role of enzymes in the formation of inflammations, sensitivities, and some cancers has been demonstrated in mammals. The importance of enzymes has led to the development of mechanistic studies, product analysis, and synthesis of inhibitors. In this study, a series of allyl and prenyl dimethoxybenzenes were synthesized and their inhibitory potency against soybean 15-Lipo-oxygenase (L1; EC 1,13,11,12) was determined. Among the synthetic compounds, 2,6-dimethoxy-1-isopentenyl-4-methylbenzene, 2,6-dimethoxy-1-geranyl-4-methylbenzene, and 2,6-dimethoxy-1-farnesyl-4-methylbenzene showed the most potent inhibitory activity with IC50 values of 7.6, 5.3, and 0.52 μm, respectively. For some of the compounds, SAR studies showed acceptable relationship between inhibitory potency and enzyme-ligand interactions. Radical scavenging assessment results apart from the SAR studies indicate that electronic properties are the major factors for lipo-oxygenase inhibition potency of the mentioned compounds. Based on the theoretical studies, it was suggested that CH…O intramolecular hydrogen bond between ortho-methoxy oxygen and methine hydrogen atoms is one of the major factors in the stability of 2,6-dimethoxyallyl(or prenyl)benzenes radical via the planarity fixation between phenyl and allyl (or prenyl) pi orbitals.
“…Orientin is one of the main flavone C‐glycosides of the purified herbal extract from the flower of T. chinensis Bunge (Sun et al, ; H. P. Li, Zhang, & Ma, ; J. Y. Liu, Li, et al, ; Wang, Geng, Wu, & An, ). Recent pharmacological studies reported that orientin has a diverse range of bioactivities including antioxidant and anti‐aging activities (Praveena, Sadasivam, Deepha, & Sivakumar, ; An et al, 2012), antimicrobial activity (Huma & Savita, ), anti‐inflammatory (Hayoung, Sae‐Kwang, Taeho, & Jong‐Sup, ; Sae‐Kwang, Soyoung, & Jong‐Sup, ; Wonhwa, Sae‐Kwang, & Jong‐Sup, ), cardioprotective (L. Y. Liu, Ma, et al, ; N. Lu, Sun, & Zheng, ) and neuroprotective effects (Benjamin, Anna, Rhun, Soi, & Ying, ; Yu et al, ). Modern pharmacological studies have shown that orientin also has antitumor activity (An, Wang, Tian, & Zhu, ; Guo et al, ).…”
Section: Introductionmentioning
confidence: 99%
“…Orientin is one of the main flavone C-glycosides of the purified herbal extract from the flower of T. chinensis Bunge H. P. Li, Zhang, & Ma, 2011;Wang, Geng, Wu, & An, 2012). Recent pharmacological studies reported that orientin has a diverse range of bioactivities including antioxidant and anti-aging activities (Praveena, Sadasivam, Deepha, & Sivakumar, 2014;, antimicrobial activity (Huma & Savita, 2012), anti-inflammatory (Hayoung, Sae-Kwang, Taeho, & Jong-Sup, 2014;Sae-Kwang, Soyoung, & Jong-Sup, 2014;Wonhwa, Sae-Kwang, & Jong-Sup, 2014), cardioprotective (L. Y. Liu, Ma, et al, 2013;N.…”
Orientin showed a broad array of biological activities, and it is the major bioactive compound in the Trollius chinensis Bunge. The aim of this study was to investigate the comparative pharmacokinetics of orientin after intravenous administration of single orientin and T. chinensis Bunge extract. Sample preparation involved a simple one-step deproteinization procedure with acetonitrile. Chromatographic separation was achieved on a Waters BEH C column with a mobile phase consisting of acetonitrile and water containing 0.1% formic acid in an isocratic elution way. The detection was accomplished in multiple reaction monitoring mode with positive electrospray ionization. The pharmacokinetic properties of orientin were compared after intravenous administrations of pure orientin and T. chinensis Bunge extract to rats with approximately the same dosage of 10 mg/kg. The results of the study indicate that the pharmacokinetics of orientin in rat plasma show significant differences between two groups. This is useful for the clinical uses of therapeutic dosing of orientin and T. chinensis Bunge.
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