Search Results (3)

Foliar water uptake (FWU) is one of the primary water sources for desert plants. Desert plants’ water uptake capacity is essential in maintaining the balance of carbon and water. However, there are few studies on FWU capacity in desert plants and the physiological and ecological characteristics that lead to differences in FWU capacity. In order to clarify FWU strategies and the influencing factors of plants in desert ecosystems, this study measured the contact angle, FWU parameters, and hydraulic parameters to explore six desert plants’ FWU capacity and the effects of leaf wettability and hydraulic parameters on FWU capacity. The results showed that all six plants had FWU capacity, among which the leaves of Nitraria sibirica Pall. and Halimodendron halodendron (Pall.) Voss had a high foliar water uptake rate (k) and high foliar water uptake accumulation (FWU storage), and the leaves of Glycyrrhiza uralensis Fisch. had a high k and low FWU storage. The leaves of Populus euphratica Oliv., Apocynum hendersonii Hook. f., and Alhagi sparsifolia Shap. had a low k and low FWU storage. Additionally, FWU capacity was mainly affected by stomatal regulation compared with leaf wettability and leaf structure. The results of this study will help to improve the understanding of the physiological and ecological adaptability of desert plants. Full article

Halimodendron halodendron has been used as forage in northwestern China for a long time. Its young leaves and flowers are edible and favored by indigenous people. In this study, eleven phenolic compounds were bioassay-guided and isolated from the aerial parts of H. halodendron for the first time. They were identified by means of physicochemical and spectrometric analysis as quercetin (1), 3,5,7,8,4'-pentahydroxy-3'-methoxy flavone (2), 3-O-methylquercetin (3), 3,3'-di-O-methylquercetin (4), 3,3'-di-O-methylquercetin-7-O-β-D-glucopyranoside (5), isorhamentin-3-O-β-D-rutinoside (6), 8-O-methylretusin (7), 8-O-methylretusin-7-O-β-D-glucopyranoside (8), salicylic acid (9), p-hydroxybenzoic acid (ferulic acid) (10), and 4-hydroxy-3-methoxy cinnamic acid (11). They were sorted as flavonols (1–6), soflavones (7 and 8), and phenolic acids (9–11). Among the compounds, flanools 1–4 revealed a strong antibacterial activity with minimum inhibitory concentration (MIC) values of 50–150 μg/mL, and median inhibitory concentration (IC₅₀) values of 26.8–125.1 μg/mL. The two isoflavones (7 and 8) showed moderate inhibitory activity on the test bacteria. Three phenolic acids (9, 10 and 11) showed strong antibacterial activity with IC₅₀ values of 28.1–149.7 μg/mL. Antifungal activities of the compounds were similar to their antibacterial activities. All these phenolic compounds showed significant antimicrobial activity with a broad spectrum as well as antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching assays. In general, the flavonol aglycones with relatively low polarity exhibited stronger activities than the glycosides. The results suggest the potential of this plant as a source of functional food ingredients and provide support data for its utilization as forage as well. Full article

Three phenolic compounds, p-hydroxybenzoic acid (1), isorhamnetin-3-O-β-D-rutinoside (2), and 3,3'-di-O-methylquercetin (5), along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC) with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v) as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3) and 3-O-methylquercetin (4). Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC). The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3) and 3-O-methylquercetin (4) (26.43% and 71.89%, respectively) in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5) at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1) at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-β-D-rutinoside (2) at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis. Full article