Survey of 55 Turkish Salvia taxa for their acetylcholinesterase inhibitory and antioxidant activities

In the current work, our target was to screen inhibitory potentials of 55 Turkish Salvia taxa, 28 of which are endemic, against acetylcholinesterase (AChE), which is a chief enzyme in pathogenesis of Alzheimer’s disease (AD). The dichloromethane, ethyl acetate, and methanol extracts prepared from 55 Salvia taxa were tested for their AChE inhibitory activity at 25, 50, and 100 μg/ml using an ELISA microplate reader. The extracts were also screened for their scavenging effect against DPPH radical and iron-chelating capacity. Total phenol and total flavonoid contents of Salvia fruticosa were determined. Among the 165 Salvia extracts screened, only the dichloromethane extract of S. fruticosa showed inhibition towards AChE at 100 μg/ml having 51.07% of inhibition, while only the dichloromethane and ethyl acetate extracts of Salvia cilicica had a notable iron-chelating capacity at 100 μg/ml having 54.71% of chelating capacity. Most of the extracts showed remarkable scavenging effect against DPPH radical.     

Anticholinesterase and antioxidant effects of the ethanol extract, ethanol fractions and isolated flavonoids from Cistus laurifolius L. leaves

In the current study, the n-hexane, chloroform, ethyl acetate, water, and n-butanol fractions obtained from the main ethanol extract of Cistus laurifolius L. were evaluated for their cholinesterase inhibitory effects against acetyl- (AChE) and butyrylcholinesterase (BChE), at 50, 100, and 200 μg/ml, using an ELISA microplate reader. The antioxidative effect of the extract and fractions was also determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelation capacity, and ferric-reducing antioxidant power (FRAP) test systems. Total phenol and flavonoid contents of the extract and fractions were calculated using Folin-Ciocalteau and aluminium chloride reagents. Three flavonoid derivatives; 3-O-methylquercetin (1), 3,7-O-dimethylquercetin (2), and 3,7-O-dimethylkaempferol (3) isolated from the CHCl₃ fraction were also tested in the same manner. Our experimental findings indicated that the ethanol extract exerted the highest AChE inhibition (80.07 ± 1.06% at 200 μg/ml). The ethyl acetate and n-butanol fractions displayed the best activity against DPPH and FRAP assays.     

Inhibitory potential of trilobatin from Lithocarpus polystachyus Rehd against α-glucosidase and α-amylase linked to type 2 diabetes

The chemical structure of the sweet compound from Lithocarpuspolystachyus Rehd was identified as trilobatin on the basis of HPLC, EIS-MS and NMR analyses. The inhibitory activities of trilobatin against α-glucosidase and α-amylase were evaluated, and the inhibition mechanism was analysed with Lineweaver–Burk plots. Also the antioxidant activity evaluation of trilobatin was conducted by DPPH radical scavenging assay. Comparing with acarbose, trilobatin showed a strong inhibitory activity against α-glucosidase and a moderate inhibitory activity against α-amylase. The Lineweaver–Burk plots analysis elucidated that trilobatin inhibited the enzyme non-competitively. DPPH scavenging activity of trilobatin (IC₅₀ = 0.57 mg/ml) was higher than rutin (IC₅₀ = 0.72 mg/ml), which indicated that trilobatin had a moderate antioxidant potential. These results suggest that trilobatin is a potential effective α-glucosidase inhibitor for management of postprandial hyperglycemia with less side effect, and provide strong rationale for further animal and clinical studies.     

Determination of antioxidative potential of lichen Usnea ghattensis in vitro

The study was aimed at evaluating the antioxidant activities of extract of Usnea ghattensis. The antioxidant activity, reducing power, superoxide anion radical scavenging and free radical scavenging activities were studied. The antioxidant activity increased with the increasing amount of extracts (2-20 mg/ml) added to the linoleic acid emulsion. Lipid peroxidation upto 73.3% was inhibited by the extract of 20 mg/ml and 39.2% by α-tocopherol at the same concentration. These effects were statistically significant (r²=0.876,P<0.01) when compared with control. However, the extract had no significant effect on superoxide anion scavenging by the PMS/NADH-NBT method. Like antioxidant activity, the reducing power and free radical scavenging activity of extract depends on concentration and increasing with increased amount of sample. The reducing power and DPPH radical-scavenging activity of U. ghattensis extract were found greater than the BHA and BHT. The results obtained in the present study indicate that U. ghattensis is a potential source of natural antioxidant.     

Antioxidant activity and proline content of leaf extracts from Dorystoechas hastata

Dorystoechas hastata (D. hastata) is a monotypic plant endemic to Antalya province of Turkey. D. hastata leaves are used to make a tea locally called “çalba tea”. Diethyl ether (E), ethanol (A), and water (W) were used for the sequential preparation of extracts from dried D. hastata leaves. A hot water extract (S) was also prepared by directly boiling the powdered plant in water. The antioxidant activities of the extracts were tested by ferric thiocyanate (FTC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods. E extract exhibited the greatest antioxidant activity with FTC method, whereas S extract exhibited the lowest IC₅₀ value (6.17 ± 0.53 μg/ml) for DPPH radical scavenging activity. Total phenolic contents of the extracts were estimated by Folin–Ciocalteu method and S extract was found to contain the highest amount (554.17 ± 20.83 mg GAE/g extract) of phenolics. Extract A contained highest flavonoid content and there was a inverse linear correlation (R² = 0.926) between IC₅₀ values for DPPH radical scavenging activity and flavonoid contents of all extracts. Reducing power of extracts increased in a concentration-dependent manner. S extract was found to possess higher reducing power than equivalent amount of ascorbic acid at 20 and 25 μg/ml concentrations. Linear correlation between reducing power and concentration of E, A, and W extracts (R² > 0.95) was observed. A, W, and S extracts contained relatively high levels of proline. The results presented suggest that D. hastata may provide a natural source of antioxidants and proline.     

Antioxidant properties of fungal chitosan from shiitake stipes

Fungal chitosan B or C was prepared by alkaline N-deacetylation of crude chitin B or C for 60, 90 and 120 min, which was obtained from air-dried shiitake stipes and its antioxidant properties studied. Chitosan showed antioxidant activities of 61.6-82.4% at 1 mg/ml and showed reducing powers of 0.42-0.57 at 10 mg/ml. At 10 mg/ml, scavenging abilities of chitosan B60 and C60 on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 28.4-31.3% whereas those of chitosan B90, B120, C90 and C120 were 44.5-53.5%. With regard to the scavenging ability on hydroxyl radicals at 0.1 mg/ml, chitosan B60 and C60 were 61.9% and 63.6%, chitosan B90 and C90 were 68.3% and 69.9% and chitosan B120 and C120 were 77.7% and 77.2%, respectively. At 1.0 mg/ml, chelating abilities of chitosan B60 and C60 on ferrous ions were 88.7-90.3% whereas those of the rest chitosan were 97.8-103%. EC₅₀ values of antioxidant activity were below 1 mg/ml whereas those of reducing powers and scavenging abilities on DPPH radicals were 7.69-16.3 mg/ml. EC₅₀ values of scavenging abilities on hydroxyl radicals were below 0.1 mg/ml whereas those of chelating abilities on ferrous ions were 0.58-0.69 mg/ml.     

Antioxidant activities of mangrove Rhizophora apiculata bark extracts

Depolymerisation of mangrove Rhizophora apiculata bark extracts in the presence of phloroglucinol nucleophiles in ethanol was carried out. The flavan-3-ols and their phloroglucinol adducts were separated using reversed phase liquid chromatography (HPLC). The HPLC analysis of mangrove R. apiculata showed that catechin was the most common component of the flavanoid monomers. The antioxidant activities of these mangrove tannins were evaluated and compared with several commercial tannins by using reducing power, DPPH and ABTS assays with butylated hydroxytoluene, BHT and l-(+)-ascorbic acid as standards. All tannins had reducing power and percentage scavenging activities similar to the (+)-catechin and l-(+)-ascorbic acid standards. In the DPPH assay, >90% of the maximum scavenging activity was attained at 30 μg ml⁻¹. Mangrove tannins had stronger antioxidant activity than the BHT standard in the DPPH assay. The results of the ABTS assay were correlated with the DPPH assay. Scavenging activity in the ABTS assay increased as the tannin concentration increased, up to a plateau at 50 μg ml⁻¹.     

Profiling of in vitro neurobiological effects and phenolic acids of selected endemic Salvia species

The ethyl acetate and methanol extracts from 16 Salvia L. species were screened for their inhibitory activity against acetylcholinesterase, butyrylcholinesterase, lipoxygenase, and tyrosinase; the enzymes linked to neurodegeneration. Their antioxidant activity was also tested using DPPH radical scavenging, metal-chelation, and ferric-reducing antioxidant power (FRAP) assays. Total flavonoid content of the extracts was determined by AlCl₃ reagent, while HPLC technique was applied for analysis of various phenolic acids in the extracts. The extracts exerted weak cholinesterase and tyrosinase inhibition, and remarkable inhibition against lipoxygenase (13.07 ± 2.73-74.21 ± 5.61%) at 100 μg ml⁻¹. The methanol extracts showed higher antioxidant activity in DPPH radical scavenging and FRAP assays. The extracts were analyzed for their gallic, protocateuchic, p-hydroxy-benzoic, vanillic, caffeic, chlorogenic, syringic, o- and p-coumaric, ferulic, rosmarinic, and tr-cinnamic acid contents and the methanol extract of Salvia ekimiana (153.50 mg 100 g⁻¹) was revealed to be the richest in terms of rosmarinic acid.     

Antioxidant properties of methanolic extracts from Agaricus blazei with various doses of γ-irradiation

Agaricus blazei Murrill (Agariaceae) was irradiated with gamma rays at doses of 2.5, 5, 10, 15 and 20 kGy and the antioxidant properties of its methanolic extracts were studied. At 7.5 and 10.0 mg/ml, antioxidant activities of methanolic extracts from 2.5 to 20 kGy γ-irradiated A. blazei were significantly higher than those of methanolic extract from the nonirradiated control. At 0.5-7.5 mg/ml, reducing powers of methanolic extracts from A. blazei with 2.5, 10, 15 and 20 kGy of irradiation and without irradiation were comparable. All methanolic extracts showed excellent scavenging abilities of 95.2-100.7% against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at 0.5 mg/ml. With regard to the scavenging ability against hydroxyl radicals, unirradiated and γ-irradiated A. blazei were comparable. Total phenols were the major naturally occurring antioxidant components found in the range of 18.77-21.48 mg/g. All EC₅₀ values were below 10 mg/ml, except values in reducing power, scavenging ability against DPPH radicals and chelating ability against ferrous ions were below 1 mg/ml. That indicates the unirradiated and irradiated A. blazei were good in antioxidant properties. Summarily, up to 20 kGy of irradiation did not remarkably affect the amounts of total antioxidant components in A. blazei.     

Phenolic composition,antioxidant and acetylcholinesterase inhibitory activities of Sclerocarya birrea and Harpephyllum caffrum (Anacardiaceae) extracts

Total phenolic content, proanthocyanidins, gallotannins, flavonoids, and antioxidant activities of Sclerocarya birrea and Harpephyllum caffrum methanolic extracts were evaluated using in vitro assays. S. birrea young stem extract contained the highest levels of total phenolic content (14.15 ± 0.03 mg GAE/g), flavonoids (1.21 ± 0.01 mg CE/g) and gallotannins (0.24 ± 0.00 mg GAE/g). H. caffrum stem bark extract had the highest content of proanthocyanidins (1.47%). The EC₅₀ values of the extracts in the DPPH free radical scavenging assay ranged from 4.26 to 6.92 μg/ml, compared to 6.86 μg/ml for ascorbic acid. A dose-dependent linear curve was obtained for all extracts in the ferric-reducing power assay. Dichloromethane and methanol extracts exhibited dose-dependent acetylcholinesterase inhibitory activity. Similarly, all extracts exhibited high antioxidant activity comparable to butylated hydroxytoluene based on the rate of β-carotene bleaching (84.1–93.9%). The two Anacardiaceae species provide a source of natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial to the health of consumers.     

Effect of ultrasonic treatment on the recovery and DPPH radical scavenging activity of polysaccharides from longan fruit pericarp

Ultrasonic technique was employed to extract polysaccharides from longan fruit pericarp (PLFP). The optimal conditions for ultrasonic extraction of PLFP were determined by response surface methodology. Box–Behnken design was applied to evaluate the effects of three independent variables (ultrasonic power, time and temperature) on the recovery and 1,1′-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of PLFP. The correlation analysis of two mathematical-regression models indicated that quadratic polynomial model could be employed to optimize the ultrasonic extraction of PLFP. From response surface plots, ultrasonic power, time and temperature exhibited independent and interactive effects on the extraction of PLFP. The DPPH radical scavenging activity of PLFP could be improved by application of various ultrasonic power, time and temperature, which was possible due to the degradation of polysaccharides to different extent. The optimal conditions to obtain the highest recovery and the strongest DPPH radical scavenging activity of PLFP were 120 W, 22 min and 60 °C, as well as 241 W, 18 min and 51 °C, respectively. Under these optimal conditions, the experimental values agreed with the predicted ones by analysis of variance. It indicated high fitness of two models used and the success of response surface methodology for optimizing PLFP extraction.     

Antioxidant and free radical scavenging activities of pigments extracted from molasses alcohol wastewater

The pigments from molasses alcohol wastewater were extracted by the macroporous resin adsorption method. The antioxidant and free radical scavenging activities of these pigments were also investigated. The adsorptive characteristics of five macroporous resins including HPD-600, HPD-500, D301-R, NKA-II and D296-R were studied and the results showed that the macroporous resin HPD-600 was most appropriate for extracting the pigments from molasses alcohol wastewater. The antioxidant and free radical scavenging activities of pigments extracted from alcohol wastewater were evaluated using nitrate, hydroxyl radical, superoxide anion radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pigment extract exhibited a concentration-dependent radical scavenging activity in all the systems. Meanwhile, scavenging activity of pigment extract in the DPPH system was found to be significantly (P < 0.05) higher than that in other systems and the 50% inhibitory concentration (IC₅₀ value) was about 0.07 mg/ml. The scavenging effect of pigment extract on superoxide anion radical was very weak with IC₅₀ value greater than 10 mg/ml.     

Evaluation of antioxidant activities and total phenolic contents of typical malting barley varieties

Fourteen typical malting barley varieties from China were evaluated for their DPPH radical, ABTS radical cation and superoxide anion radical scavenging activities, reducing power, metal chelating activities, and total phenolic contents (TPC). All barley samples exhibited significant antioxidant activities determined by different assays, and contained significant levels of phenolic compounds. Gan4 and Wupi1 barley exhibited the highest DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power. Gan4 and Humai16 barley showed the highest TPC, whereas the highest superoxide anion radical scavenging activity and metal chelating activity were found in Huaimai19 and Ken3 barley, respectively. The Pearson correlation analysis revealed that the TPC showed strong correlations with DPPH radical scavenging activity, ABTS radical cation scavenging activity, and reducing power (P < 0.01), whereas its correlations with superoxide anion radical scavenging activity and metal chelating activity were poor (P > 0.05). Moreover, DPPH radical scavenging activity, ABTS radical cation scavenging activity and reducing power were well positively correlated with each other (P < 0.01). Principal component analysis (PCA) was applied to understand the interrelationships among the measured antioxidant activity evaluation indices, and to gain an overview of the similarities and differences among the 14 barley varieties.     

Chemical analysis,antioxidant, antiinflammatory and anticholinesterase activities of Origanum ehrenbergii Boiss and Origanum syriacum L. essential oils

The essential oils of Origanum ehrenbergii and O. syriacum collected in Lebanon were analysed by GC and GC–MS and evaluated for their anticholinesterase, NO production inhibitory activities, and antioxidant properties. O.ehrenbergi essential oil was characterised by the presence of 37 components, representing 94.9% of the total oil of which thymol (19%) and p-cymene (16.1%) were the main abundant compounds. Thirty-six compounds characterised the O.syriacum essential oil, representing 90.6% of the total oil. The most abundant components were thymol (24.7%) and carvacrol (17.6%). O. ehrenbergii demonstrated interesting scavenging effects on DPPH with an IC₅₀ value of 0.99 μg/ml. In addition, both O. ehrenbergii and O. syriacum oils inhibited oxidation of linoleic acid after 30 min of incubation, as well as after 60 min of incubation with IC₅₀ values of 42.1 and 33.6 μg/ml, and 46.9 and 58.9 μg/ml, respectively. Interestingly, O. ehrenbergii oil inhibited NO production in the murine monocytic macrophage cell line RAW 264.7 with an IC₅₀ value of 66.4 μg/ml. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of the Ellman’s method. O. ehrenbergii exhibited a strong activity against both cholinesterases with IC₅₀ values of 0.3 μg/ml. The data suggest that O. ehrenbergii and O. syriacum oils could be used as a valuable new flavour with functional properties for food or nutriceutical products with particular relevance to supplements for the elderly.     

Purification and identification of novel antioxidant peptides from enzymatic hydrolysates of sardinelle (Sardinellaaurita) by-products proteins

In order to utilise sardinelle (Sardinellaaurita) protein by-products, which is normally discarded as industrial waste in the process of fish manufacturing, heads and viscera proteins were hydrolysed by different proteases to obtain antioxidative peptides. All hydrolysates showed different degrees of hydrolysis and varying degrees of antioxidant activities. Hydrolysate generated with crude enzyme extract from sardine (Sardinapilchardus) displayed high antioxidant activity, and the higher DPPH radical-scavenging activity (87 ± 2.1% at 2 mg/ml) was obtained with a degree of hydrolysis of 6%. This hydrolysate was fractionated by size exclusion chromatography on a Sephadex G-25 into eight major fractions (P₁–P₈). Fraction P₄, which exhibited the highest DPPH scavenging activity, was then fractionated by reversed-phase high performance liquid chromatography (RP-HPLC). Seven antioxidant peptides were isolated. The molecular masses and amino acids sequences of the purified peptides were determined using ESI-MS and ESI-MS/MS, respectively. Their structures were identified as Leu-His-Tyr, Leu-Ala-Arg-Leu, Gly-Gly-Glu, Gly-Ala-His, Gly-Ala-Trp-Ala, Pro-His-Tyr-Leu and Gly-Ala-Leu-Ala-Ala-His. The first peptide displayed the highest DPPH radical-scavenging activity (63 ± 1.57%; at 150 μg/ml) among these peptides.     

Evaluation of reducing power and radical scavenging activities of water and ethanol extracts from sumac (Rhus coriaria L.)

The purpose of this study was to determine the reducing power, metal chelating, and radical scavenging capabilities of water and ethanol extracts of sumac (Rhus coriaria L.), comparatively. The water and ethanol extracts of sumac were evaluated for their radical scavenging activities by means of the DPPH and DMPD assays. Water extract of sumac (R. coriaria L.) scavenged radicals effectively with EC₅₀ values of 36.4 ??g/ml for DPPH free radical and 44.7 ??g/ml for DMPD cation radical. Similarly, the total reducing power of water extract was found higher than ethanol extract in both potassium ferricyanide reduction (FRAP) and cupric ions reduction capacity methods (CUPRAC). 2,2′-Bipyridine was used to determine the metal chelating activity and the result of water extract was found higher than ethanol extract. Total phenolic and total flavonoid contents of both extracts were studied as well. The values of water extract were found to be higher than that of ethanol extract. The present study found that water extracts of sumac (R. coriaria L.) have effective antioxidant and radical scavenging activities as compared to ethanol extracts.     

Evaluation of antioxidant activity of aqueous extract of some selected nutraceutical herbs

The objectives of this study were to examine the antioxidant activities and free radical scavenging effects of extracts of aqueous leaves of Psidium guajava L. (PE), Camellia sinensis (GABA tea; CE), Toona sinensis Roem. (TE) and Rosemarinus officinalis L. (RE). Among the four extracts, PE exhibited the strongest efficiency and showed over 50% scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at the concentration of 100 μg/mL. The reducing power of four nutraceutical herbs was in the order of PE > RE > CE > TE. The antioxidant activities of nutraceutical herbs were evaluated in a liposomes oxidation system promoted by Fe³⁺/ascorbic acid/H₂O₂. PE still showed the strongest antioxidant activity and exhibited over 95% inhibition at concentration of 50 μg/mL. The antioxidant activity of TE was still lower than that of other herbal plants; however, it also displayed 89% inhibition at concentration of 250 μg/mL. RE exhibited well inhibitory effects on the UVB-induced oxidation of erythrocyte ghosts at lower concentration (100 μg/mL). However, the protection of PE on the UVB-induced oxidation was significantly raised with increasing the concentrations and reached 95.4% inhibitory effects at concentration of 500 μg/mL. These results show that the tested herbal tea, especially PE could be considered as a natural antioxidant source.     

Antioxidant and free radical scavenging potential of Achillea santolina extracts

The antioxidative activities of hydroalcoholic extract of Achillea santolina were investigated employing various established in vitro systems including total antioxidant activity in linoleic acid emulsion system, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals scavenging, reducing power, and inhibitory effect on protein oxidation as well as the inhibition of Fe²⁺/ascorbate induced lipid peroxidation in rat liver homogenate. Total phenolic and flavonoid content of A. santolina extract (ASE) was also determined by a colorimetric method. The results revealed that ASE has notable inhibitory activity on peroxides formation in linoleic acid emulsion system along with concentration-dependent quenching of DPPH and superoxide radicals. Furthermore, the extract showed both nonsite-specific (Fe²⁺ + H₂O₂ + EDTA) and site-specific (Fe²⁺ + H₂O₂) hydroxyl radical scavenging suggesting potent hydroxyl radical scavenging and chelating ability for iron ions in deoxyribose degradation model. A linear correlation between ASE and the reducing power was also observed (r² = 0.9981). ASE prevents thiobarbituric acid reactive substances formation in Fe²⁺/ascorbate induced lipid peroxidation in rat liver tissue in a dose-dependent manner. Moreover, free radical induced protein oxidation was suppressed significantly by the addition of ASE over a range of concentration. These results clearly demonstrated that A. santolina extract possess a marked antioxidant activity.     

Estimation of neuroprotective effects of Laurocerasus officinalis Roem. (cherry laurel) by in vitro methods

Dichloromethane, ethyl acetate, acetone, methanol, and water extracts prepared from the fruits and leaves of Laurocerasus officinalis Roem. (LO) (Rosaceae) were screened for their cholinesterase inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the key enzymes in pathogenesis of Alzheimer's disease (AD), using ELISA microplate reader at 50, 100, and 200 ??g mL⁻¹. As AD is associated with oxidative stress, the antioxidant activity of the extracts was also tested by radical-forming methods against 2,2-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylendiamine (DMPD), and superoxide radicals as well as iron-related methods; iron-chelating capacity and ferric-reducing antioxidant power (FRAP) assays. Total phenol and flavonoid quantification was achieved using Folin-Ciocalteau and AlCl₃ reagents, respectively. The highest AChE (44.01 ± 1.75%) and BChE (19.91 ± 0.37%) inhibition was caused by the LO-leaf-methanol extract 200 ??g mL⁻¹, while it showed the best radical-scavenging activity against DPPH at 2000 ??g mL⁻¹. Only, the dichloromethane and water extracts of the fruits and the leaf water extract had an iron-chelating capacity, while the leaf methanol extract displayed the highest FRAP. The leaf methanol extract (113.45 ± 0.71 mg g⁻¹ extract) was found to be the richest in total phenols, while the leaf acetone extract (139.90 ± 4.64 mg g⁻¹ extract) had the most abundant amount of total flavonoids.     

牛肝菌多糖的提取及抗氧化性研究

该试验以云南牛肝菌烘干粉末为原料,多糖得率为评价指标,从料液比、超声时间和超声温度等因素,对牛肝菌粉末粗多糖的提取工艺进行优化;同时对牛肝菌多糖清除1,1-二苯基苦基苯肼自由基（DPPH·）和羟基自由基（·OH）的能力进行研究。结果表明,牛肝菌粗多糖得率受各因素的影响程度依次为料液比＞超声时间＞超声温度。当料液比为1∶15（g∶mL）,超声时间为2 h,超声温度为60 ℃时,牛肝菌粗多糖得率可达41.76%。牛肝菌粗多糖对DPPH·和·OH的半抑制浓度（IC50）值分别为0.75 mg/mL和5.12 mg/mL,当多糖质量浓度为1 mg/mL、10 mg/mL时,多糖对DPPH·和·OH的清除率可达71.19%、80.69%。