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Plant Source Foods
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Glycosides are natural organic compounds, usually of plant origin, formed by a sugar (carbohydrate) named glycone linked to a non-sugar compound named aglycone or genin (37). By hydrolysis, glycosides yield one or more sugars. The aglycon may be a terpene, a flavonoid, a coumarin, or any other natural product. Among the sugars found in natural glycosides, D-glucose is the most abundant one, L rhamnose and L-fructose also occur quite frequently (37). Based on the chemical properties, glycosides can be classified into Cardiac glycosides, Phenolic glycosides (flavonoids, lignans and other phenolic compounds), Aldehyde glycosides, Cyanogenic glycosides, Anthraquinone and and Saponin glycosides (37). The aglycones of cardiac glycosides or digitalis glycosides are: digitoxin, digoxin, and gitoxin, and they have a direct effect on myocardial contraction. They are cardiotonic. Saponins are compounds that possess a lipid soluble aglycone consisting of either a sterol or a triterpenoid attached to a water-soluble sugar unit (monosaccharide or oligosaccharide) (33–34, 37). Saponins are found in peas, beans, tomatoes, spinach, asparagus, onions, garlic, potatoes, and ginseng (33).
An Overview of Molecular Nutrition
Published in Nicole M. Farmer, Andres Victor Ardisson Korat, Cooking for Health and Disease Prevention, 2022
Vincent W. Li, Catherine Ward, Delaney K. Schurr
Phytochemicals that are the most common in the human diet are not necessarily the most active within the body, because of lower intrinsic activity or because they are poorly absorbed from the intestine, highly metabolized, or rapidly eliminated (Manach et al., 2004). Most polyphenols are too hydrophilic (attracted to water) to penetrate the small intestinal wall by passive diffusion. To date, transporters for polyphenols have not yet been identified in humans. However, there are exceptions. Flavonoid phytochemicals in the form of aglycones or glucosides are easily absorbed in the small intestine. For example, the glucoside flavonol quercetin reaches maximum absorption 0.5–0.7 hours after ingestion. However, rutin, a glycoside flavonol has 15% of the absorption of quercetin.
Honey-Based Polyphenols: Extraction, Quantification, Bioavailability, and Biological Activities
Published in Megh R. Goyal, Arijit Nath, Rasul Hafiz Ansar Suleria, Plant-Based Functional Foods and Phytochemicals, 2021
Csilla Benedek, John-Lewis Zinia Zaukuu, Zsanett Bodor, Zoltan Kovacs
The stability of phenolic compounds was checked by Biesaga and Pyrzynska during ultrasonic- or microwave-assisted extraction (USE or MAE). The authors confirmed that the extraction assisted by ultrasound delivers generally higher yields than the conventional LLE. It has been proven that phenolic acids and glycosides are highly stable during MAE and USE treatments. Aglycones of flavonols (e.g., quercetin) are unstable under such conditions. Therefore, a low amount of yields are obtained for extraction of Aglycones of flavonols from honey with MAE and USE treatments [13].
Phytochemical constituents and protective efficacy of Schefflera arboricola L. leaves extract against thioacetamide-induced hepatic encephalopathy in rats
Published in Biomarkers, 2022
Ali M. El-Hagrassi, Abeer F. Osman, Mostafa E. El-Naggar, Noha A. Mowaad, Sahar Khalil, Manal A. Hamed
Acid hydrolysis was carried out for 2 h at 100 °C using 10 mL hydrochloric acid (2 mol/L). The yielded aglycones were then extracted with ethyl acetate. The ethyl acetate layer was dried with anhydrous Na2SO4 and evaporated. The hydrolyzed extract was subjected to paper chromatography (PC) Whatman No. 1 (Whatman Ltd., Maidstone, Kent, England) using 15% AcOH/water (Acetic acid: H2O, 15: 85) and BAW (n-Butanol: Acetic acid: H2O 4:1:5, upper layer) to detect the flavonoid aglycones. Also, the aqueous layer was carefully neutralized, then subjected to PC investigation using BBPW (Benzene: n-Butanol: pyridine: Water; 1:5:3:3, upper layer) to detect the sugars. The dried chromatograms were visualized by an aniline phthalate reagent (Swanston-Flatt et al. 1990). The sugar spots were observed in daylight. The Rf values of tested sugars were compared with those of reference sugars (Al-Wakeel et al. 1988, Saleh et al. 1990).
Flavonoids as inhibitors of human neutrophil elastase
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Katarzyna Jakimiuk, Jakub Gesek, Atanas G. Atanasov, Michał Tomczyk
The significance of O-glycosylation at the A-ring (C7) and C-ring (C3) positions can be observed by comparing the inhibitory levels of apigenin and luteolin and its 7-O-glucosides cosmosiin, and cynaroside, respectively. Based on the IC50 values, aglycones possess stronger activity while their 7-O-glucosides reveal no significant inhibitory effect. It is worth mentioning that 3-O-rhamnosylation of quercetin and kaempferol also reduced their activity. The values presented in Table 3 suggest that glucosylation or rhamnosylation at positions C-7 or C-3 presumably produce steric hindrances that prevent molecules from binding to enzymes126. In addition, a comparison of an anti-elastase potential of apigenin and apigenin 4′-O-β-d-glucoside leads to the conclusion that glucosylation of the hydroxyl group in B-ring also reduces its activity70,77.
Triglyceride-mimetic prodrugs of scutellarin enhance oral bioavailability by promoting intestinal lymphatic transport and avoiding first-pass metabolism
Published in Drug Delivery, 2021
Xinran Wang, Cai Zhang, Ning Han, Juyuan Luo, Shuofeng Zhang, Chunguo Wang, Zhanhong Jia, Shouying Du
To find a solution to this problem, we reviewed the literature on the absorption and metabolism of scutellarin (Qiu et al., 2007; Gao et al., 2011; Wang et al., 2011; Xing et al., 2011; Gao et al., 2012; Trevaskis et al., 2015; Ryšánek et al., 2020). It was found that scutellarin was difficult to penetrate intestinal epithelial cells and most of it was broken down by β-glucuronidase to generate aglycones. The generated aglycones can be absorbed through intestinal epithelial cells and metabolized before entering the portal vein (Wang et al., 2017). Further glycosylation occurs after entering the liver, which accelerates excretion (Figure 3). These studies indicate that poor membrane permeability, high intestinal capillary metabolism, and liver first-pass metabolism are the root causes of poor oral bioavailability of scutellarin. Intestinal capillary absorption pathway is difficult to guarantee an acceptable oral bioavailability of scutellarin.