Bioactivity-Guided Isolation of Phytochemicals from Vaccinium dunalianum Wight and Their Antioxidant and Enzyme Inhibitory Activities

Vaccinium dunalianum Wight, usually processed as a traditional folk tea beverage, is widely distributed in the southwest of China. The present study aimed to investigate the antioxidant, α-glucosidase and pancreatic lipase inhibitory activities of V. dunalianum extract and isolate the bioactive components. In this study, the crude extract (CE) from the buds of V. dunalianum was prepared by the ultrasound-assisted extraction method in 70% methanol and then purified with macroporous resin D101 to obtain the purified extract (PM). Five fractions (Fr. A–E) were further obtained by MPLC column (RP-C18). Bioactivity assays revealed that Fr. B with 40% methanol and Fr. D with 80% methanol had better antioxidant with 0.48 ± 0.03 and 0.62 ± 0.01 nM Trolox equivalent (TE)/mg extract for DPPH, 0.87 ± 0.02 and 1.58 ± 0.02 nM TE/mg extract for FRAP, 14.42 ± 0.41 and 19.25 ± 0.23 nM TE/mg extract for ABTS, and enzyme inhibitory effects with IC₅₀ values of 95.21 ± 2.21 and 74.55 ± 3.85 for α-glucosidase, and 142.53 ± 11.45 and 128.76 ± 13.85 µg/mL for pancreatic lipase. Multivariate analysis indicated that the TPC and TFC were positively related to the antioxidant activities. Further phytochemical purification led to the isolation of ten compounds (1–10). 6-O-Caffeoylarbutin (7) showed significant inhibitory effects on α-glucosidase and pancreatic lipase enzymes with values of 38.38 ± 1.84 and 97.56 ± 7.53 µg/mL, and had the highest antioxidant capacity compared to the other compounds.     

Geographic Variability of Berry Phytochemicals with Antioxidant and Antimicrobial Properties

The aim of this study was to determine the variability of several chemical compounds and the antioxidant and antimicrobial activities of eight types of berries harvested from two different geographical regions in the same year. The analyses were performed on bilberry, black currant, gooseberry, red currant, raspberry, sea buckthorn, strawberry and sour cherry, which were handpicked during the summer of 2019, in the same periods when they are typically harvested for consumer purposes. Total anthocyanins content (TAC), total flavonoids content (TFC), total polyphenolic compounds (TPC), determination of the Ferric-Reducing Antioxidant Power (FRAP), determination of the DPPH free radical scavenging assay (RSA), determination of nine phenolic compounds by HPLC-UV assay and antimicrobial activity were determined for undiluted hydroalcoholic extracts of all the studied berries. The results showed that the berries from Romania were richer in antioxidant compounds than the berries from Russia. The TPC content varied between 4.13–22.2 mg GAE/g d.w., TFC between 3.33–8.87 mg QE/g d.w. and TAC between 0.13–3.94 mg/g d.w. The highest variability was determined for TPC. Regarding the antioxidant activity assessed by FRAP assay, values were between 6.02–57.23 µmols TE/g d.w. and values for the RSA method between 18.44–83.81%. From the eight types of berries analyzed, bilberries and raspberries had the highest antioxidant activity considering both regions and both determination methods. Not only the type, but also the environmental and cultivation conditions in which the berries grow, can lead to variations in their chemical composition. The extracted polyphenolic compounds from the studied berries showed antibacterial properties on pathogens, such as Escherichia coli, Bacillus subtilis and Staphyloccocus aureus. The inhibitory action on Salmonella typhi and fungi Candida albicans and Aspegillus niger was absent to very low. The antimicrobial activity of the hydroalcoholic extracts was dependent on the provenance of the berries, too.     

Total Polyphenols Content,Antioxidant and Antimicrobial Activities of Leaves of Solanum elaeagnifolium Cav. from Morocco

Solanum elaeagnifolium is among the invasive plants of Morocco; studies on its chemical composition and biological activities are few in number in Morocco. S. elaeagnifolium has shown molluscicidal and nematicidal and cancer-inhibitory effects, anti-inflammatory, analgesic activity, and antibacterial activity. The objective of this research is to improve this plant and assess its antibacterial and antioxidant properties as well as its total polyphenolic content (TPC) and total flavonoid content (TFC). The Folin-Ciocalteu method and the aluminium-trichloride method were used to determine TPC and TFC in hydro-ethanolic (HEE) and hydro-acetonic (HAE) leaf extract. Three assays were performed to determine the antioxidant activity: the DPPH test (radical 2,2’-diphenyl-1-picrylhydrazyl), the FRAP test (Ferric Reducing Antioxidant Power), and the TAC test. Disk diffusion and microdilution were used to test antibacterial activity against four pathogenic bacteria and Candida albicans. The hydro-ethanolic extract 2.54 ± 0.4 mg EAG/g has a greater polyphenol concentration than the hydro-acetonic extract 1.58 ± 0.03 mg EAG/g. Although the flavonoid content of the hydro-acetonic extract (0.067 ± 0.001 mg EQ/g) is larger than that of the hydro-ethanolic extract (0.012 ± 0.001 mg EQ/g), the flavonoid content of the hydro-ethanolic extract (0.012 ± 0.001 mg EQ/g). The DPPH values were IC-50 = 0.081 ± 0.004 mg/mL for hydro-ethanoic extract and 0.198 ± 0.019 mg/mL for hydro-acetonic extract, both extracts superior to BHT (0.122 ± 0.021 g/mL). While the FRAP assay showed a low iron-reducing power values for both extracts compared to BHT), the overall antioxidant activity of the two extracts was found to be considerable. The overall antioxidant activity of the hydro-ethanolic extract was 8.95 ± 0.42 mg EAA/g, whereas the total antioxidant activity of the hydro-acetonic extract was 6.44 ± 0.61 mg EAA/g. In comparison with the antibiotic Erythromycin, HAE and HEE from S. elaeagnifolium leaves demonstrated significant antibacterial action. HAE had the best inhibitory efficacy against Bacillus subtilis DSM 6333, with an inhibition diameter of 10.5 ± 0.50 mm and a MIC of 7.5 ± 0.00 mg/mL, as well as against Proteus mirabilis ATCC 29906, with an inhibitory diameter of 8.25 ± 0.75 mm and a MIC of 15 ± 0.00 mg/mL.     

In Vitro Screening for Anti-Acetylcholinesterase and Antioxidant Activities of Hottonia palustris L. Extracts and Their Unusual Flavonoids

Hottonia palustris L. is from the genus Hottonia (Primulaceae), and the understanding of its phytochemical and pharmacological properties is limited. In this study, the use of chromatographic techniques led to the isolation of a further eleven compounds, including three new flavonoids: 2′,5-dihydroxyflavone 2′-O-β-glucopyranoside, 5,6-dihydroxyflavone 6-O-(6”-O-glucopyranosyl)-β-glucopyranoside (hottonioside A), and 4′,5,7-trihydroxyflavone 7-O-(2”-O-β-glucuronide)-β-glucopyranoside. Their structures were determined using extensive 1D and 2D NMR data and mass spectrometry (HRMS). The qualitative assessment of the chemical composition of the investigated extracts and fractions was performed using the LC-HRMS technique. Furthermore, the antioxidant potential of extracts, fractions, and compounds and their ability to inhibit acetylcholinesterase were also evaluated. Thus, we may conclude that the observed biological effects are the result of the presence of many biologically active compounds, of which dibenzoylmethane is the most active. Therefore, H. palustris is a source of substances with desirable properties in the prevention and treatment of neurodegenerative diseases.     

Phenolic Profile,Antioxidant and Enzyme Inhibitory Activities of Leaves from Two Cassia and Two Senna Species

Several species within the genera Cassia or Senna have a treasure of traditional medicines worldwide and can be a promising source of bioactive molecules. The objective of the present study was to evaluate the phenolic content and antioxidant and enzyme inhibition activities of leaf methanolic extracts of C. fistula L., C. grandis L., S. alexandrina Mill., and S. italica Mill. The two Cassia spp. contained higher total polyphenolic content (42.23–49.75 mg GAE/g) than the two Senna spp., and C. fistula had significantly (p ˂ 0.05) the highest concentration. On the other hand, the Senna spp. showed higher total flavonoid content (41.47–59.24 mg rutin equivalent per g of extract) than that found in the two Cassia spp., and S. alexandrina significantly (p ˂ 0.05) accumulated the highest amount. HPLC–MS/MS analysis of 38 selected bioactive compounds showed that the majority of compounds were identified in the four species, but with sharp variations in their concentrations. C. fistula was dominated by epicatechin (8928.75 µg/g), C. grandis by kaempferol-3-glucoside (47,360.04 µg/g), while rutin was the major compound in S. italica (17,285.02 µg/g) and S. alexandrina (6381.85). The methanolic extracts of the two Cassia species exerted significantly (p ˂ 0.05) higher antiradical activity, metal reducing capacity, and total antioxidant activity than that recorded from the two Senna species’ methanolic extracts, and C. fistula displayed significantly (p ˂ 0.05) the highest values. C. grandis significantly (p ˂ 0.05) exhibited the highest metal chelating power. The results of the enzyme inhibition activity showed that the four species possessed anti-AChE activity, and the highest value, but not significantly (p ≥ 0.05) different from those obtained by the two Cassia spp., was exerted by S. alexandrina. The Cassia spp. exhibited significantly (p ˂ 0.05) higher anti-BChE and anti-Tyr properties than the Senna spp., and C. grandise revealed significantly (p ˂ 0.05) the highest values. C. grandise revealed significantly (p ˂ 0.05) the highest α- amylase inhibition, while the four species had more or less the same effect against the α-glucosidase enzyme. Multivariate analysis and in silico studies showed that many of the identified phenols may play key roles as antioxidant and enzyme inhibitory properties. Thus, these Cassia and Senna species could be a promising source of natural bioactive agents with beneficial effects for human health.     

Chitosan Elicitation Impacts Flavonolignan Biosynthesis in Silybum marianum (L.) Gaertn Cell Suspension and Enhances Antioxidant and Anti-Inflammatory Activities of Cell Extracts

Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.     

蒲公英黄酮抗氧化活性的构效关系分析

蒲公英作为传统的中药材,具有抗氧化、抗肿瘤、抗菌、抗炎等多种药用价值。黄酮是蒲公英发挥抗氧化作用的重要活性成分。蒲公英黄酮抗氧化性能的实验研究备受关注,然而从分子水平对蒲公英黄酮结构与抗氧化活性之间的内在关系缺乏系统的研究。本文借助于密度泛函理论,针对蒲公英中5种重要的黄酮化合物(槲皮素、芦丁、木犀草素、芹菜素、香叶木素),通过优化结构参数、捕获DPPH自由基的热力学能量分析,NBO电荷分布、半醌自由基的自旋密度分析等方面深入探讨了蒲公英黄酮化合物抗氧化活性的构效关系及内在规律。结果表明：5种蒲公英黄酮化合物抗氧化活性为芦丁>槲皮素>木犀草素>>香叶木素>芹菜素,酚羟基的位置是影响蒲公英黄酮抗氧化活性差异的主要因素。蒲公英黄酮不同位点抗氧化活性的高低与其酚羟基上H原子的电荷分布、黄酮自由基的稳定性成正比关系,自由基单电子的离域程度和分子内氢键的稳定化作用共同决定了B环4’-OH是蒲公英黄酮的关键活性位点。     

Antioxidant and Anti-Inflammatory Activities of Six Flavonoids from Smilax glabra Roxb

This study aimed to isolate, prepare and identify the main flavonoids from a standardized Smilax glabra flavonoids extract (SGF) using preparative HPLC, MS, ¹H NMR and ¹³C NMR, determine the contents of these flavonoids using UPLC, then compare their pharmacological activities in vitro. We obtained six flavonoids from SGF: astilbin (18.10%), neoastilbin (11.04%), isoastilbin (5.03%), neoisoastilbin (4.09%), engeletin (2.58%) and (−)-epicatechin (1.77%). The antioxidant activity of six flavonoids were evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS⁺) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the anti-inflammatory activity of six flavonoids were evaluated by determining the production of cytokines (IL-1β, IL-6), nitric oxide (NO) using enzyme linked immunosorbent assay and the NF-κB p65 expression using Western blotting in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The results showed that (−)-epicatechin, astilbin, neoastilbin, isoastilbin and neoisoastilbin had strong antioxidant activities, not only in DPPH and ABTS⁺ radicals scavenging capacities, but in FRAP system. Furthermore, all the six flavonoids could significantly inhibit the secretion of IL-1β, IL-6, NO (p < 0.01) and the protein expression of NF-κB p-p65 (p < 0.01) in LPS-stimulated RAW264.7 cells. This study preliminarily verified the antioxidant and anti-inflammatory activities of six flavonoids in S. glabra.     

Chemical Composition,Antioxidant and Anticancer Activities of Leptocarpha rivularis DC Flower Extracts

An evaluation of antioxidant and anticancer activity was screened in Leptocarpha rivularis DC flower extracts using four solvents (n-hexane (Hex), dichloromethane (DCM), ethyl acetate (AcOEt), and ethanol (EtOH)). Extracts were compared for total extract flavonoids and phenol contents, antioxidant activity (2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), ferric reducing antioxidant potential (FRAP), total reactive antioxidant properties (TRAP) and oxygen radical absorbance capacity (ORAC)) across a determined value of reduced/oxidized glutathione (GSH/GSSG), and cell viability (the sulforhodamine B (SRB) assay). The most active extracts were analyzed by chromatographic analysis (GC/MS) and tested for apoptotic pathways. Extracts from Hex, DCM and AcOEt reduced cell viability, caused changes in cell morphology, affected mitochondrial membrane permeability, and induced caspase activation in tumor cell lines HT-29, PC-3, and MCF-7. These effects were generally less pronounced in the HEK-293 cell line (nontumor cells), indicating clear selectivity towards tumor cell lines. We attribute likely extract activity to the presence of sesquiterpene lactones, in combination with other components like steroids and flavonoids.     

HESI-MS/MS Analysis of Phenolic Compounds from Calendula aegyptiaca Fruits Extracts and Evaluation of Their Antioxidant Activities

Considering medicinal plants as an inexhaustible source of active ingredients that may be easily isolated using simple and inexpensive techniques, phytotherapy is becoming increasingly popular. Various experimental approaches and analytical methods have been used to demonstrate that the genus Calendula (Asteraceae) has a particular richness in active ingredients, especially phenolic compounds, which justifies the growing interest in scientific studies on this genus’ species. From a chemical and biological viewpoint, Calendula aegyptiaca is a little-studied plant. For the first time, high-performance liquid chromatography combined with negative electrospray ionization mass spectrometry (HPLC-HESI-MS) was used to analyze methanolic extracts of Calendula aegyptiaca (C. aegyptiaca) fruits. Thirty-five molecules were identified. Flavonoids (47.87%), phenolic acids (5.18%), and saponins (6.47%) formed the majority of these chemicals. Rutin, caffeic acid hexoside, and Soyasaponin βg’ were the most abundant molecules in the fruit methanolic extract, accounting for 17.49% of total flavonoids, 2.32 % of total phenolic acids, and 0.95% of total saponins, respectively. The antioxidant activity of the fruit extracts of C. aegyptiaca was investigated using FRAP, TAC, and DPPH as well as flavonoids and total phenols content. Because the phenolic components were more extractable using polar solvents, the antioxidant activity of the methanolic extract was found to be higher than that of the dichloromethane and hexane extracts. The IC50 value for DPPH of methanolic extract was found to be 0.041 mg·mL⁻¹. Our findings showed that C. aegyptiaca is an important source of physiologically active compounds.     

Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba

Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP assays were used for determining the antioxidant capability. The results of total flavonoids and phenolics contents showed that ethyl acetate fraction (EAF) possessed the highest flavonoids and phenolics with values of 159.7 ± 2.5 mg rutin equivalents/g and 107.6 ± 2.0 mg galic acid equivalents/g, respectively. The results of in vitro hypoglycemic activity showed that all samples had effective α-glucosidase inhibition capacities, and EAF possessed the best inhibitory effect with IC₅₀ value of 1.58 ± 0.24 μg/mL. In addition, n-butanol fraction (NBF) significantly promoted the glucose uptake rate of 3T3-L1 adipocytes. HPLC-MS analysis and molecular docking results proved the interactions between candidates and α-glucosidase. The results of antioxidation capacities showed that EAF possessed the best antioxidation abilities with DPPH, ABTS, and FRAP. In summary, the hypoglycemic activity of PAH might be related to the inhibition of α-glucosidase (EAF > PEF > NBF) and the promotion of glucose uptake in 3T3-L1 adipocytes (NBF). Simultaneously, the antioxidation capacity of PAH might be related to the abundant contents of flavonoids and other phenolics (EAF > PEF > NBF).     

Two New Isoprenoid Flavonoids from Sophora flavescens with Antioxidant and Cytotoxic Activities

Sophora flavescens is a regularly used traditional Chinese medicine. In an attempt to discover adequate active agents, the isoprenoid flavonoids from S. flavescens were further investigated. In this work, two new compounds (1–2, kurarinol A-B) together with 26 known ones (3–28) were isolated and elucidated on the basis of extensive NMR, UV and MS analyses. Furthermore, the antioxidant activity of all constituents was assessed through ABTS, PTIO and DPPH methodologies and also were evaluated for cytotoxic activity by three tumor cell lines (HepG2, A549 and MCF7) and one human normal cell line (LO2 cells). As a result, a multitude of components revealed significant inhibitory activity. In particular, compound 1–2 (kurarinol A-B), two new flavanonols derivatives, exhibited the most potent ABTS inhibitory activity with IC₅₀ of 1.21 µg/mL and 1.81 µg/mL, respectively. Meanwhile, the new compound 1 demonstrated remarkable cytotoxicity against three cancer cells lines with IC₅₀ values ranging from 7.50–10.55 μM but showed little effect on the normal cell. The two new isoprenoid flavonoids could be promising antioxidant and anti-tumor nature agents.     

Purification and Identification of Flavonoid Molecules from Rosa setate x Rosa rugosa Waste Extracts and Evaluation of Antioxidant,Antiproliferative and Antimicrobial Activities

Rosa setate x Rosa rugosa is widely used in the essential oil industry and generates large amounts of waste annually. The purpose of this research is the recycling of bioactive flavonoids from rose waste biomass to develop high-value products. Resin screening and adsorption/desorption dynamic analysis showed that HP20 resin was suitable to purify the flavonoids from R. setate x R. rugosa waste extracts. Under the optimal enrichment process, the product had a 10.7-fold higher purity of flavonoids with a satisfactory recovery of 82.02%. In total, 14 flavonoids were identified in the sample after purification by UHPLC-QTOF-MS. Moreover, the DPPH and ABTS assays revealed that the flavonoids-purified extracts exhibited higher antioxidant activities than the crude extracts. Meanwhile, the purified extracts presented stronger antiproliferative activity against HepG2, Caco-2, MCF-7 and A549 cell lines. The bacteriostatic effects of the purified extracts against four bacteria (Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Staphylococcus epidermidis (S. epidermidis), Pseudomonas aeruginosa (P. aeruginosa)) and yeast (Candida albicans (C. albicans)) were stronger compared with the crude extracts. It was concluded that flavonoids-enriched extracts from R. setate x R. rugosa waste had the potential to be applied in functional food and pharmaceutical industries.     

Phytonutrients,Colorant Pigments,Phytochemicals, and Antioxidant Potential of Orphan Leafy Amaranthus Species

The underutilized Amaranthus leafy vegetables are a unique basis of pigments such as β-cyanins, β-xanthins, and betalains with radical scavenging capacity (RSC). They have abundant phytonutrients and antioxidant components, such as pigments, vitamins, phenolics, and flavonoids. Eight selected genotypes (four genotypes from each species) of underutilized Amaranthus leafy vegetables were evaluated for phytonutrients, pigments, vitamins, phenolics, flavonoids, and antioxidants in a randomized complete block design under ambient field conditions with three replicates. The studied traits showed a wide range of variations across eight genotypes of two species of Amaranthus leafy vegetables. The highest fat, β-xanthins, K, dietary fiber, Mg, β-cyanins, Mn, chlorophyll ab, Zn, TP, TF, betalains, chlorophyll a content, and (RSC) (DPPH) and RSC (ABTS⁺) were obtained from A. tricolor accessions. Conversely, the highest protein, Cu, carbohydrates, Ca, and chlorophyll b content were obtained from A. lividus accessions. The highest dry matter, carotenoids, Fe, energy, and ash were obtained from A. tricolor and A. lividus. The accession AT2 confirmed the highest vit. C and RSC (DPPH) and RSC (ABTS+); AT5 had the highest TP content; and AT12 had the highest TF content. A. tricolor accessions had high phytochemicals across the two species, such as phytopigments, vitamins, phenolics, antioxidants, and flavonoids, with considerable nutrients and protein. Hence, A. tricolor accessions can be used as high-yielding cultivars comprising ample antioxidants. The correlation study revealed that vitamin C, pigments, flavonoids, β-carotene, and phenolics demonstrated a strong RSC, and showed a substantial contribution to the antioxidant potential (AP) of A. tricolor. The investigation exposed that the accessions displayed a plentiful origin of nutritional values, phytochemicals, and AP with good quenching ability of reactive oxygen species (ROS) that provide enormous prospects for nourishing the mineral-, antioxidant-, and vitamin-threatened community.     

Isolation,Purification, and Antioxidant Activities of Polysaccharides from Choerospondias axillaris Leaves

The extraction, characterization and antioxidant activity of polysaccharides from Choerospondias axillaris leaves were investigated in the present study. Two purified polysaccharide fractions, CALP-1 and CALP-2, were isolated from crude Choerospondias axillaris leaf polysaccharides (CALP) by DEAE-52 cellulose chromatography and Sephadex G-100 column chromatography. The characteristics of CAL-1 and CALP-2 were determined by using High-performance Gel Permeation Chromatography (HPGPC), High-Performance Anion-Exchange Chromatography, HPAEC (HPAEC-PAD) and Fourier transform infrared spectroscopy (FTIR). CALP-1 with molecular weight of 11.20 KDa was comprised of Rhamnose, Arabinose, Galactose, Glucose, Xylose, Mannose and galacturonic acid in a molar ratio of 5.16:2.31:5.50:27.18:1.00:0.76:1.07. CAL-2 with molecular weight of 8.03 KDa consisted of Rhamnose, Arabinose, Galactose, Glucose, and galacturonic acid at a ratio of 1.38:3.63:18.84:8.28:1.45. FTIR revealed that CALP-1 and CALP-2 were acidic polysaccharides. The antioxidant activity of crude CALP, CALP-1 and CALP-2 was evaluated in vitro. The fraction CALP-2 was demonstrated to be of polysaccharide nature containing a large percentage of Galactose but no Xylose and Mannose. The antioxidant activity assays showed that CALP-1 and CALP-2 exhibited antioxidant and scavenging activities on hydroxyl and DPPH radicals in vitro. Compared with pure polysaccharide, crude CALP exhibited stronger anti-oxidant activities. These results will provide a better understanding of Choerospondias axillaris leaf polysaccharide and promote the potential applications of Choerospondias axillaris leaf polysaccharide in the pharmacological field and as a natural antioxidant.     

ESI-MS/MS Analysis of Phenolic Compounds from Aeonium arboreum Leaf Extracts and Evaluation of their Antioxidant and Antimicrobial Activities

Aeonium is a genus of succulents belonging to the Crassulaceae family. Their importance in traditional medicine has stimulated both pharmacological and chemical research. In this study, we optimized extraction, separation, and analytical conditions using a high performance liquid chromatographic method coupled with electrospray ionization mass spectrometry by the negative mode (HPLC-ESI-MS) in order to, for the first time, determine thirty-four compounds from Aeonium arboreum leaves. Twenty-one of them are assigned among which are sixteen flavonoids and five phenolic acids. FRAP, TAC, DPPH, and ABTS^•+ radical scavenging were used to evaluate antioxidant activity. The obtained IC₅₀ values ranged from 0.031 to 0.043 mg.mL⁻¹ for DPPH and between 0.048 and 0.09 mg·mL⁻¹ for ABTS^•+. Antimicrobial activity was also assessed. The obtained minimum inhibitory concentrations (MIC) of these extracts ranged from 12.5 to 50 µg·mL⁻¹ against Micrococcus luteus, Listeria ivanovii, Staphylococcus aureus, Salmonella enterica, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, and Fusarium oxysporum, and from 25 to 50 µg·mL⁻¹ against Candida albicans. Therefore, these extracts can be considered as a potential source of biological active compounds.     

竹叶黄酮提取工艺及体外抗氧化性研究综合实验

设计一个将中药有效成分提取、含量测定、抗氧化性能研究等集于一体,针对中药特色专业开设的综合实验。该实验以毛竹竹叶为原料,对竹叶总黄酮提取工艺参数进行考察。最佳工艺参数为：乙醇浓度为70%,料液比为1∶25,提取时间为2.0 h,提取温度为80℃时,总黄酮提取率可达2.24 mg/g,并进一步研究了竹叶黄酮的抗氧化性能。本实验涉及无机化学、有机化学中的提取理论知识,分析化学中数据处理方法及仪器分析中紫外分光光度计的使用。在锻炼了学生动手操作能力的基础上,又提高了学生对实验结果进行分析、评价的综合能力。     

Comparative Studies on Essential Oil and Phenolic Content with In Vitro Antioxidant,Anticholinesterase, Antimicrobial Activities of Achillea biebersteinii Afan. and A. millefolium subsp. millefolium Afan. L. Growing in Eastern Turkey

The potential applications of Achillea species in various industries have encouraged the examination of their phytochemical components along with their biological potential. In the present study, phenolic contents and essential oil compositions together with the in vitro biological activities of the aerial parts from Achillea biebersteinii Afan. and Achillea millefolium subsp. millefolium Afan. collected from Turkey were evaluated. Different solvent extracts (n-hexane, chloroform, methanol, water) were prepared and their antimicrobial, anticholinesterase, and antioxidant activities were studied. The LC-MS/MS results revealed the presence of 16 different phenolic compounds, including chlorogenic acid, rutin, quercetin, and luteolin glycosides, in methanolic extracts. According to GC-FID and GC/MS results, the primary components of the oils were identified as 1,8-cineole (32.5%), piperitone (14.4%), and camphor (13.7%) in A. biebersteinii and 1,8-cineole (12.3%) and β-eudesmol (8.9%) in A. millefolium subsp. millefolium. The infusion and methanolic extracts of both species were found to be rich in their total phenolic content as well as their antioxidant and anticholinesterase activity. In contrast, the n-hexane and chloroform extracts of both species showed strong antimicrobial activity with MIC values ranging from 15 to 2000 μg/mL. Our findings suggest that the investigated Achillea species could be evaluated as potent natural agents, and further studies into the promising extracts are needed.     

New Adenosine Derivatives from Aizoon canariense L.: In Vitro Anticholinesterase,Antimicrobial, and Cytotoxic Evaluation of Its Extracts

Aizoaceae is a large succulent family characterized by many psychoactive species. Aizoon canariense L., a wild neglected plant traditionally used in gastrointestinal ailments, has been the subject of a limited number of phytochemical and biological studies. Therefore, herein, we investigated the in vitro cytotoxic, antimicrobial, and anticholinesteraseactivity of the aerial parts of A. canariense L. and analyzed the phytochemical compositions of the lipoidal and alkaloidal fractions. Petroleum ether extract showed the presence of behenic and tricosylic acid, while an in-depth investigation of the alkaloidal fraction revealed the identification of new adenine based alkaloids (1–5), which were isolated and identified for the first time from Aizoon canariense L. Their structures were elucidated based on extensive spectroscopic analyses. The alkaloidal extract showed a powerful cytotoxic effect (IC₅₀ 14–28 μg/mL), with the best effect against colon carcinoma, followed by liver and breast carcinomas. The alkaloidal extract also had a potent effect against Candida albicans and Escherichia coli, with minimum inhibitory concentrations (MIC) values of 312.5 and 625 µg/mL. The in vitro anticholinesterase activity was potent, with IC₅₀ < 200 ng/mL for the tested extracts compared with 27.29 ± 0.49 ng/mL for tacrine.     

Chemical Composition,Antioxidant, and Antimicrobial Activities of Leaves of Ajuga Iva

The main objective of this research was to study the biological characteristics in terms of antioxidant and antimicrobial activities of Ajuga iva and determine the best analytical and extraction methods applicable to this specie and studied compounds. A short screening of its nutritional value in terms of chemical composition is also included. A. iva leaves were analyzed for crude protein (CP), cell wall [neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL)], minerals, fatty acids, essential oils, and phenolic compounds. Mature aerial parts of A. iva were randomly collected during the Spring season from Mograne-Zaghouan, Tunisia. Leaves of A. iva contained 13.4 ± 0.4% CP, 26.3 ± 0.35% NDF, 20.2 ± 0.42% ADF, and 5.13 ± 0.21% ADL. Mineral content (13.0 ± 0.45%) was mainly composed of potassium (4.5% g DM) and magnesium (4.25% DM). Leaves of A. iva had linolenic (26.29 ± 0.760%) and linoleic (37.66 ± 2.35%) acids as the main components of the acid profile. Thymol was found to be the most dominant (23.43%) essential oil, followed by 4-vinylguaiacol (14.27%) and linalool (13.66%). HPLC-PDA-ESI-MS/MS analysis pointed out the presence of phytoecdysteroids. Phenolic acids and flavonoids, such as glycosylated derivatives of naringenin, eriodyctiol, and apigenin, were detected in the methanol extract of A. iva leaves. Our results underline the importance of choosing proper extraction methods and solvents to extract and characterize the described compounds profile of A. iva leaves. Results also show A. iva leaves as a potential source of functional ingredients with beneficial health-promoting properties. Overall, leaves of A. iva have low biological activities (antioxidant and antimicrobial activities) with a chemical composition suitable as a feed for ruminants in rangeland pasture. It also has low-grade antibacterial or medicinal characteristics when fed to ruminants.