Isorhamnetin, Hispidulin, and Cirsimaritin Identified in Tamarix ramosissima Barks from Southern Xinjiang and Their Antioxidant and Antimicrobial Activities

Abstract

As a natural potential resource, Tamarix ramosissima has been widely used as barbecue skewers for a good taste and unique flavor. The polyphenolics in the branch bark play a key role in the quality improvement. The purposes of the present work were to explore the polyphenolic composition of T. ramosissima bark extract and assess their potential antioxidant and antimicrobial activities. Hispidulin and cirsimaritin from T. ramosissima bark extract were first identified in the Tamarix genus reported with UPLC-MS analysis. Isorhamnetin (36.91 μg/mg extract), hispidulin (28.79 μg/mg extract) and cirsimaritin (13.35 μg/mg extract) are rich in the bark extract. The extract exhibited promising antioxidant activity with IC50 values of 117.05 μg/mL for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 151.57 μg/mL for hydroxyl radical scavenging activities, as well as excellent reducing power with an EC50 of 93.77 μg/mL. The bark extract showed appreciable antibacterial properties against foodborne pathogens. Listeria monocytogenes was the most sensitive microorganism with the lowest minimum inhibitory concentration (MIC) value of 5 mg/mL and minimum bactericidal concentration (MBC) value of 10 mg/mL followed by S. castellani and S. aureus among the tested bacteria. The T. ramosissima bark extract showed significantly stronger inhibitory activity against Gram-positive than Gram-negative bacteria. Nevertheless, this extract failed to show any activity against tested fungi. Overall, these results suggested that T. ramosissima shows potential in improving food quality due to its highly efficacious antioxidant and antibacterial properties.

Protective Effects of Gynostemma pentaphyllum (var. Ginpent) against Lipopolysaccharide-Induced Inflammation and Motor Alteration in Mice

“…Furthermore, it appears to block inflammatory action by inhibiting the expression of interleukin-6 (IL-6) and the activity of tumour necrosis factor-α (TNF-α) in cultures of LPS-stimulated macrophages [ 56 ]. Inhibitory actions of the inflammatory process were also observed in animal models treated with dihydroquercetin, isorhamnetin and anethole [ 57 ].…”

Isorhamnetin and Hispidulin from Tamarix ramosissima Inhibit 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine (PhIP) Formation by Trapping Phenylacetaldehyde as a Key Mechanism

“…The levels of TRE added to lamb patties were determined using the Standards for the Use of Food Additives (GB 2760-2014), with a maximum level of 0.50 mg/g of antioxidants in roast meat products; three levels (Level p 1-3) of TRE were established in the present study (Table 1). According to Ren et al [5], the concentrations of isorhamnetin, hispidulin and cirsimaritin were 36.91, 28.79 and 13.35 mg/g TRE, respectively, and the approximate levels of each compound are presented in Table 1 (Level p 1-3). The concentrations of phenylalanine and creatinine in raw lamb were determined (1307 and 870 mg/kg, respectively) in the present study but were approximately 25 times lower than the concentrations in the PhIP model.…”

“…All other chemicals and solvents used in this study were of HPLC or analytical grade. TRE was prepared using our previously reported procedure [5].…”

“…Many flavonoids have been identified from various species of Tamarix, such as quercetin, isoquercetin, apigenin, amentoflavone, (+)-catechin, rhamnocitrin, isorhamnetin, tamarixetin, chrysoeriol and rhamnazin [1][2][3][4]. Hispidulin and cirsimaritin were firstly identified among 13 flavonoids detected in the genus Tamarix from southern Xinjiang, along with isorhamnetin, which are the main three flavonoids present in T. ramosissima ( Figure 1) [5]. Tamarix has been widely used as barbecue skewers to obtain a good taste and a unique flavor of roast lamb in China, specifically in southern Xinjiang.…”

Special Issue: From Natural Polyphenols to Synthetic Bioactive Analogues

“…A further contribution by Ren et al [3] is focused on polyphenols from Tamarix ramosissima bark, to determine their potential antioxidant and antimicrobial activities. A total of 13 polyphenolic compounds were identified by UPLC-MS analysis.…”