China
Africa
Explore chapters and articles related to this topic
Molecular substrates of ethanol feedstocks
Published in Ruben Michael Ceballos, Bioethanol and Natural Resources, 2017
Ferulic acid, a hydroxycinnamic acid produced via the phenylpropanoid synthesis pathway, will link to lignin via ether bonds while simultaneously forming ester linkages to sugar residues within hemicellulose (Gubler et al., 1985; Iiyama et al., 1994; Sun et al., 2002). Its esters attach to residues of xylans, such as arabinofuranosyl or xylopyranosyl residues (Ishii and Hiroi, 1990; Levigne et al., 2004). Esters of ferulic acid may form dimeric complexes that cross-link arabinoxylan chains. It has been suggested that dehydrodiferuloyl dimers containing diester linkages between polysaccharides can cross-link to lignin via ether bonds (Hartley et al., 1990; Lam et al., 1992b). Other esters, linked with lignin, are present in cell wall including esters of p-coumaric acid; however, these do not cross-link lignin and hemicellulose as ferulic acid (FA) does (Lam et al., 1992a, 1994; Sun et al., 2002). Similar to ferulic acid, p-coumaric acid is also a hydroxycinnamic acid synthesized via the phenylpropanoid biosynthetic pathway. A second way lignin associates with hemicellulose is via lignin alcohol ether bonds with OH groups of polysaccharides (Watanabe et al., 1989). For example, a study using woody material from gymnosperms and angiosperms showed that glucose and mannose residues form ether linkages with lignin alcohols (Lam et al., 1990). The third way in which lignin interacts with hemicellulose in the cell wall structure involves uronyl ester bonds between the hydroxyl groups of lignin alcohols and uronic acid on 4-O-methyl-d-glucuronic acid residues in hemicellulose (Das et al., 1984; Watanabe and Koshijima, 1988).
Selected fungi of the genus Lactarius - screening of antioxidant capacity, antimicrobial activity, and genotoxicity
Published in Journal of Toxicology and Environmental Health, Part A, 2022
Miroslava Stanković, Violeta Mitić, Vesna Stankov Jovanović, Marija Dimitrijević, Jelena Nikolić, Gordana Stojanović
Table 2 shows the phenolic acid profiles of the studied mushroom species. Our results demonstrate the presence of diverse phenolic acids namely p- hydroxybenzoic acid, p-coumaric acid, caffeic acid, ferulic acid, vanillic acid, syringic acid and chlorogenic acid. L. volemus contained the highest amount of phenolic acids, whereas L. deliciosus the least. Vanillic acid, p-coumaric acid and syringic acid were present in all mushrooms at high concentrations. p-hydroxybenzoic acid was found in all studied species except L. piperatus. All examined mushrooms contained ferulic acid, except L. deliciosus. The highest amount of syringic acid was found in L. volemus, and the lowest in L. deliciosus. Vanillic acid was identified as the major phenolic acid in L. deliciosus. Protocatechuic acid was found only in L. volemus and L. piperatus.
Antioxidant potentialities and gastroprotective effect of Reichardia picroides extracts on Ethanol/HCl induced gastric ulcer rats
Published in International Journal of Environmental Health Research, 2023
Samia Oueslati, Raja Serairi Beji, Feten Zar Kalai, Merieme Soufiani, Walid Zorrig, Salama Aissam, Kamel Msaada, Cherkaoui El Modafar
Based on the effectiveness of the R. picroides extracts in antioxidant defence, the evaluation of gastroprotective effect has been highlighted. In physiological conditions, it is known that gastric mucosal is generally a crucial source of reactive oxygen species (ROS) (Aviello and Knaus 2018). However, disruption of oxidative balance is considered an essential reason in the pathogenesis and the maintenance of gastric ulcers, since the overproduction of ROS and other free radicals favour the impairment of stomach antioxidant defence mechanisms (Bhattacharyya et al. 2014). This activity was assessed on the acidified ethanol-induced gastric ulcer. The famotidine was considered as a potent agent to treat gastric ulceration (PP = 48.8%). Obtained results showed the efficiency effect of R. picroides roots (PP = 54.6%). Besides, this activity depends on organ doses. Obtained results revealed that root activity with a dose of 500 mg/kg was better than activity with 125 and 250 mg/kg. In the same context, it has been observed that especially the 500 mg/kg dose of methanol extract of Eremurus spectabilis decreased UI and MDA parameters at the approximate value of the standard drug famotidine (Karaoğlan et al. 2018). Besides, Ben Mansour et al. (2022) demonstrated that p-coumaric acid inhibits ulcers with 55%, 73% and 83.3% at the dose of 50 mg/kg, 100 mg/kg and 150 mg/kg, respectively. The correction and the decrease of gastric lesions by the highest roots dose (500 mg) are confirmed by its efficiency against oxidative stress in which this extract decreased lipid peroxidation and enhance SOD activity. This enzyme is essential in providing gastroprotection since it prevents oxidative harm (Danai et al. 2021) which is responsible for transforming the superoxide anion (O2-) into hydrogen peroxide (H2O2) and oxygen (O2) (Boeing et al. 2021) and stimulates the expression of CAT and GPX activities. Concerning protection percentage and in vivo enzymatic activities, the beneficial effect of R. picroides root extracts (500 mg) was clearly confirmed by Principal Component Analysis (Figure 4), which revealed strong positive correlations linking group 6 to PP, SOD, CAT and GPX.