Evaluation of bioactive flavonoids in Citri Reticulatae Pericarpium from different regions and its association with antioxidant andα-glucosidase inhibitory activities

Background:To explore the differences of 14 batches of Citri Reticulatae Pericarpium from different regions.Methods:The main aim of this study was to develop a high-performance liquid chromatography method-photodiode array detection for determining the contents of five flavonoids and the chromatographic fingerprints of Citri Reticulatae Pericarpium from different regions.Theα-glucosidase inhibitory activities and antioxidant properties of Citri Reticulatae Pericarpium,based on free-radical scavenging assays against 1,1-diphenyl-2-picrylhydrazyl,2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),and hydroxyl radicals,were estimated and compared.Results:Among the tested compounds,the content of hesperidin(13.386-68.235 mg/g)was the highest and that of hesperitin(0.045-0.277 mg/g)was the lowest.In comparing different sources of Citri Reticulatae Pericarpium,the contents of narirutin in Citri Reticulatae Pericarpium from Guangdong(0.824-0.851 mg/g)and Sichuan(1.069-1.204 mg/g)provinces of China were lower than in other provinces.In contrast,nobiletin(8.429-12.237 mg/g)and tangeretin(3.947-4.613 mg/g)were most abundant in Guangdong sources of Citri Reticulatae Pericarpium,followed by samples from Sichuan Province(nobiletin:6.761-7.658 mg/g;tangeretin:3.422-3.933 mg/g).Correlation analysis showed that nobiletin and tangeretin were the main contributors to the antioxidant capacity,and narirutin was the main active component inhibiting theα-glucosidase activity of Citri Reticulatae Pericarpium.Conclusion:This work revealed that the intrinsic quality of Citri Reticulatae Pericarpium was affected by different growing regions,which provides a scientific basis for controlling the quality of Citri Reticulatae Pericarpium and rationally developing and utilizing Citri Reticulatae Pericarpium.

Cucurbitane-Type Triterpene Glycosides from Momordica charantia and Their α-Glucosidase Inhibitory Activities

Ten cucurbitane-type triterpene glycosides,including five new compounds named charantosides H(1),J(2),K(3),momor-characoside A(4),goyaglycoside-l(5),and five known compounds(6-10),were isolated from the EtOAc extract of Momor-dica charantia fruits.The chemical structures of these compounds were identified by 1D and 2D NMR and HRESIMS spectroscopic analyses.Configurations of new compounds were determined by ROESY correlations and comparison of their 13C NMR data with literature reported values.All compounds were evaluated for their inhibition againstα-glucosidase,in which compounds 2,5,7,8,9 showed moderate inhibitory activities with IC50 values ranging from 28.40 to 63.26μM comparing with the positive control(acarbose,IC5087.65±6.51μM).

α-Glucosidase inhibitors isolated from medicinal plants

Objective:α-Glucosidase inhibitors can be used as a new class of antidiabetic drug.By competitively inhibiting glycosidase activity,these inhibitors help to prevent the fast breakdown of sugars and thereby control the blood sugar level.This study provides a wealth of information aboutα-glucosidase inhibitors isolated from medicinal plants;this knowledge will be useful in finding more potent antidiabetic candidates from the natural resources for the clinical development of antidiabetic therapeutics.Results:411 compounds exhibitingα-glucosidase inhibitory activity were summarized and isolated them from medicinal plants.The compound classes isolated include:terpenes(61)from 14 genus,alkaloids(37)from 11 genus,quinines(49)from 4 genus,flavonoids(103)from 24 genus,phenols(37)from 9 genus,phenylpropanoids(73)from 20 genus,sterides(8)from 5 genus,and other types of compounds(43).Conclusion:Compounds withα-glucosidase inhibitory activity are abundant in nature and can be obtained from several sources.They have highα-glucosidase inhibitory potential,and can be clinically developed for treating diabetes mellitus.

α-Glucosidase inhibitor produced by an endophytic fungus, Xylariaceae sp. QGS 01 from Quercus gilva Blume

Xylariaceae sp.QGS 01,an endophytic fungus isolated from the stem of Quercus gilva Blume showed high-glucosidase inhibitory activity.α-Glucosidase inhibitor have the role as one of carbohydrate-hydrolyzing enzymes to postpone absorption of glucose in the digestive organs.The α-glucosidase inhibitor constituents were isolated from the ethyl acetate extract of the mycellium of endophytic fungi Xylariaceae sp.QGS 01 using a bioassay-guided fractionation technique.Further separation and purification of the active fraction led to the isolation of constituents with strong inhibitory activities against-glucosidase:8-hydroxy-6,7-dimethoxy-3-methylisocoumarine(1)with inhibitory concentration(IC50)values against-glucosidase from Saccharomyces cerevisiae of 41.75μg/mL,while quercetin as the standard had an IC50 value of 4.80g/mL.The results of the present study showed that the endophytic fungus Xylariaceae sp.QGS 01 is potentially a rich source of antidiabetic medicine.

Rapid identification of stigmastane-type steroid saponins from Vernonia amygdalina leaf based onα-glucosidase inhibiting activity and molecular networking

Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsillitis,diabetes,pneumonia.The current study was designed to combine molecular networking(MN)with diagnostic ions for rapid identification ofΔ^(7,9(11))stigmastane-type saponins which were theα-glucosidase inhibitory active substances in V.amygdalina.First,theα-glucosidase inhibitory activities of fiveΔ^(7,9(11))stigmastane-type steroid saponins that were previously isolated were screened,which indicated that theΔ^(7,9(11))stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes.Furthermore,a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN,MolNetEnhancer and unsupervised substructure annotation(MS2LDA).Based on this strategy,other sevenΔ^(7,9(11))stigmastane-type steroid saponins were identified from this plant.Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V.amygdalina leaf.

Flavonoids from Litchi(Litchi chinensis Sonn.) Seeds and Their Inhibitory Activities on α-Glucosidase

With the bioactivity-guided method,a new flavanone glycoside,together with nine known flavonoids were isolated from 50% aqueous ethanol of litchi（Litchi chinensis Sonn.） seeds.The chemical structure of the new compound was elucidated via 1D and 2D nuclear magnetic resonance（NMR） techniques and mass spectrometry to be （2S）-pinocembrin-7-O-（6＂-O-α-L-arabinosyl-β-D-glucopyranoside）（1）,and the nine known compounds were determined to be quercetin（2）,phlorhizin（3）,pinocembrin-7-O-glucoside（4）,kaempferol-7-O-β-D-glucopyranoside（5）,onychin（6）,nairutin（7）,narcissin（8）,pinocembrin-7-O-[（6＂-O-β-D-glucopyranoside）-β-D-glucopyranoside]（9） and pinocembrin-7-O-[（2＂,6＂-di-O-α-L-rhamnopyranosyl）-β-D-glucopyranoside]（10）.Some of the isolated flavonoids were tested for their inhibitory effects on α-glucosidase.And compounds 2 and 3 showed stronger inhibitory activity than positive control.

Vitellaria paradoxa nutshells from seven sub-Saharan countries as potential herbal medicines for treating diabetes based on chemical compositions, HPLC fingerprints and bioactivity evaluation

The aim of the study was to determine the feasibility of the Vitellaria paradoxa nutshell as a new medicinal resource for treating diabetes. A total of forty-one compounds were identified by HPLC-DAD-Q-TOF-MS and phytochemical methods in V. paradoxa nutshell methanol extract. Based on HPLC fingerprints, four characteristic constituents were quantified and the origin of twenty-eight V. paradoxa nutshells from seven sub-Saharan countries was compared, which were classified into three groups with chemometric method. Twenty-eight samples contained high total phenolic content, and exhibited moderate-higher antioxidant activity and strong α-glucosidase inhibitory activity. Furthermore, all fractions and isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities, and α-glucosidase inhibitory action mechanism of four characteristic constituents including protocatechuic acid, 3, 5, 7-trihydroxycoumarin,(2 R, 3 R)-(+)-taxifolin and quercetin was investigated via molecular docking method, which were all stabilized by hydrogen bonds with α-glucosidase. The study provided an effective approach to waste utilization of V. paradoxa nutshell, which would help to resolve waste environmental pollution and provide a basis for developing potential herbal resource for treating diabetes.

大果榕果实乙醇提取物抗氧化活性及对α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性

研究大果榕果实的多酚含量及其抗氧化活性、α-葡萄糖苷酶和乙酰胆碱酯酶抑制活性,为其进一步开发利用奠定基础。以采自海南保亭七仙岭的大果榕果实为实验材料,用体积分数65%的乙醇提取大果榕果实多酚,采用Folin-酚法测定总酚含量。对获得的大果榕果实多酚进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS)自由基、羟自由基(·OH)清除率以及α-葡萄糖苷酶抑制活性和乙酰胆碱酯酶抑制活性测定。结果表明:大果榕果实多酚含量较高,达1.92 mg/g(以干质量计),其对DPPH自由基、ABTS+·和·OH均具有显著的清除活性,且呈质量浓度依赖性,IC50值分别为141.25、91.20、45.71μg/m L;大果榕果实多酚对α-葡萄糖苷酶抑制活性强于阳性对照阿卡波糖,且呈现明显的质量浓度依赖性,IC50值为102.33μg/m L;同时大果榕果实多酚对乙酰胆碱酯酶也具有一定的抑制活性,IC50值为4.9 mg/m L。研究结果表明大果榕果实多酚具有良好的抗氧化性、α-葡萄糖苷酶抑制活性和一定的乙酰胆碱酯酶抑制活性。

海南山竹果实不同部位多酚提取物抗氧化活性、乙酰胆碱酯酶和α-葡萄糖苷酶抑制活性研究

了解海南山竹果皮和果肉的多酚含量及其抗氧化活性、乙酰胆碱酯酶抑制活性和α-葡萄糖苷酶抑制活性,为引导消费、开发利用奠定基础。以采自海南五指山的山竹果实为材料,用95%的乙醇提取山竹果皮和果肉多酚,采用福林-酚法测定总酚含量。对获得的山竹果皮和果肉多酚提取物进行羟自由基(·OH)、DPPH自由基、ABTS自由基清除率以及乙酰胆碱酯酶抑制活性和α-葡萄糖苷酶抑制活性测定。结果表明,山竹果皮多酚含量很高,达21.36mg/g(干重),对·OH、DPPH自由基和ABTS+·均具有良好的清除活性,且呈现浓度依赖性,IC50分别为37.39、41.34、41.37μg/mL;山竹果皮多酚对乙酰胆碱酯酶和α-葡萄糖苷酶也具有很强的抑制活性,且呈现浓度依赖性,IC50分别为29.46、7μg/mL;山竹果肉多酚含量较低,为0.388mg/g(干重),清除DPPH自由基、ABTS+·和·OH活性较弱,但表现出浓度依赖效应。山竹果肉多酚对α-葡萄糖苷酶具有中等程度的抑制活性(IC50为2.24mg/mL),对乙酰胆碱酯酶抑制活性较弱。山竹果皮多酚具有良好的抗氧化性、乙酰胆碱酯酶抑制活性和α-葡萄糖苷酶抑制活性;山竹果肉多酚具有中等程度的α-葡萄糖苷酶抑制活性,一定的抗氧化性和乙酰胆碱酯酶抑制活性。

玉米须总黄酮抗糖基化、乙酰胆碱酯酶和α-葡萄糖甘酶抑制活性分析

研究玉米须总黄酮抗糖基化、乙酰胆碱酯酶和α-葡萄糖甘酶抑制活性。采用内部沸腾法提取玉米须总黄酮,优化其工艺条件,并对其进行分析。在单因素实验基础上,采用Plackett-Burman法对7个相关因素进行评价,筛选出具有显著性差异的4个因素,并对其进行响应面优化。结果表明,内部沸腾法提取玉米黄酮最佳条件为解析时间16min,解析剂浓度73%,提取时间20min,提取温度为61℃,总黄酮提取得率为4.75±0.69%;玉米须黄酮对晚期糖基化终产物、乙酰胆碱酯酶和α-葡萄糖苷酶具有一定抑制效果,呈现浓度依赖性,IC50分别为467.90、73.07、151.04μg/mL。抗糖基化、乙酰胆碱酯酶和α-葡萄糖甘酶抑制活性与黄酮含量呈正相关(相关系数分别为0.83、0.90和0.87;P<0.05),该研究结果可为潜在的天然产物抑制剂开发提供理论依据。

Screening potential α-glucosidase inhibitors from Anemarrhena asphodeloides using response surface methodology coupled with grey relational analysis

Objective: To screen potential α-glucosidase inhibitors from Anemarrhena asphodeloides.Methods: Response surface methodology employing Box-Behnken design was used to optimize conditions for the extraction of α-glucosidase inhibitory active compounds from A. asphodeloides. The powders(20.0 g) of A. asphodeloides were extracted under the optimized conditions. The extract was applied to a D-101 macroporous resin column. It was eluted with ethanol and water to give six fractions. Compounds from the active fraction were identified by UPLC-Q-TOF-MS. The structure-activity relationship was discussed based on grey relational analysis.Results: The optimum extraction conditions were as follows: ethanol concentration, 100%; extraction temperature, 51 ℃; and solvent to solid ratio, 23 mL/g. It indicated that the active compounds were concentrated into 80% ethanol fraction. Twenty five steroid saponins from 80%ethanol fraction were identified by UPLC-Q-TOF-MS. Peaks 19 and 23 were tentatively identified as new structures. The predicted α-glucosidase inhibitory activities of the compounds were 7 > 2 > 1 > 22 > 23 > 3 > 9 > 21 > 24 > 4 > 13 > 8 > 14 > 16 > 17 > 25 > 6 > 19.Conclusion: The fraction eluted by 80% ethanol showed the best inhibitory activity. After analyzing the data of UPLC-Q-TOF-MS, 25 steroid saponins were tentatively identified in this fraction.

Termitomenins F and G,Two New Lignan Glucosides from Terminalia chebula var.tomentella(Kurz)C.B.Clarke

The extensive chemical investigation on the branches and leaves of Terminalia chebula var.tomentella(Combretaceae)led to the isolation of two new lignan glucosides with a furofuran skeleton,termitomenins F(1)and G(2).In addition,19 known compounds including five lignan glucosides(3-7),six hydrolyzable tannins(8-13)and eight simple phenolics(14-21)were also identified.Their structures were determined by comprehensive spectroscopic analyses.It is noted that 8 and 9 were C-glycosidic hydrolyzable tannins with one hexahydroxydiphenoyl and one gallagyl group linked to an open-chain glucosyl C-1/O-2/O-3 and O-4/O-6,respectively,which were rarely found in plants.Nine known compounds,6-9,13,and 18-21,were procured from the titled plant for the first time,while 3-5,10-12 and 14-17 were also found in the fruits.Notably,the known hydrolyzable tannins 8-13 exhibited strongerα-glucosidase inhibitory activities with IC_(50) values ranging from 0.10 to 3.12μM,than the positive control,quercetin(IC_(50)=9.38±0.33μM).

New polychlorinated bibenzyls from Rhododendron minutiflorum

Five new polychlorinated bibenzyls(1-5)along with 3 known compounds(6-8)were isolated from the stems and leaves of Rhododendron minutiflorum.The chemical structures of all the isolates were determined by spectroscopic methods,and compounds 1 and 2 were further verified by single-crystal X-ray diffraction analyses.Compounds 1-5 were halogenated compounds which bear three to five chlorine atoms in their chemical structures.Biologi-cally,compounds 2,5 and 6 showed varying degrees of toxicity toward the Asian citrus psyllid(Diaphorina citri)with LD_(50) values 27.15,17.02 and 16.20 mg/L,respectively.These values were comparable to the positive control matrine(LD_(50)=11.86 mg/L),which were calculated using observations on day 6.Meanwhile,compound 4 hadα-glucosidase inhibitory activity with IC_(50) value of 17.87±0.74μM.

Structural Elucidation and Total Synthesis of Trichodermotin A,A Natural α-Glucosidase Inhibitor from Trichoderma asperellum

A pair of alkaloid enantiomers possessing a novel 1-oxaspiro[4.4]non-3-ene-2,7-dione skeleton,trichodermotin A(1),was obtained from the fungus Trichoderma asperellum.Spectroscopic data,X-ray diffraction,and ECD calculations were used to establish its structure and absolute configuration.(−)-1 showed significantα-glucosidase inhibitory activity(IC_(50)=10.1μmol/L vs.60.1μmol/L of positive control).A plausible biosynthetic pathway originating from L-β-phenylalanine was proposed,and a facile total synthesis was further accomplished.The key reaction of our synthetic strategy was a domino aza-Michael/lactonization in one pot,leading to the pivotal 4-amino-oxaspiro[4.4]octane scaffold.

Screening of probiotics with efficient α-glucosidase inhibitory ability and study on the structure and function of its extracellular polysaccharide

Inhibition ofα-glucosidase activity is an important strategy in lowering the concentration of blood sugar.In this paper,using domestic and foreign characteristic food-derived substances as the sources of lactobacillus,the performance of them were evaluated by measuring the strains’α-glucosidase inhibitory ability.Finally,the cell-free extracellular supernatants(CFS)of Lactobacillus rhamnosus LB1lac10 was determined to have the highest α-glucosidase inhibition ability.Based on the Nanopore third-generation sequencing technology platform,the genome of LB1lac10 was sequenced and functional gene annotation was performed.After that,the biological activity and structural composition of the exopolysaccharide produced by L.rhamnosus LB1lac10 were studied.The purified exopolysaccharide EPS1-1 also showed efficientα-glucosidase inhibitory ability.The structure and conformation characteristics of EPS1-1 were further analyzed.The EPS1-1 from L.rhamnosus LB1lac10 had a molecular weight of 88,650 Da,and it was mainly composed of mannose,glucuronic acid,glucose,xylose,galactose,and arabinose.From the FT-IR and NMR analyses,EPS1-1 had functional groups of a typical polysaccharide structure and contained two types of glycosidic bonds with α-configuration pyranose.The main glycosidic bond corresponded to→4)-α-D-Glcp-(1→,which might be an important reason why EPS1-1 could inhibit α-glycosidase.Thermodynamic studies showed that EPS1-1 had high heat resistance to meet the needs of food processing.The results suggested that L.rhamnosus LB1lac10 could be used as a potential probiotic to lower blood sugar,and the EPS1-1 has the potential to serve as a naturalα-glycosidase inhibitor to regulate the concentration of blood glucose.

Antioxidant and anti-diabetic activities in commercial and homemade pomegranate molasses in Lebanon

Pomegranate fruit and its derived products are rich sources of bioactive compounds.They have many biological activities.Pomegranate molasses(PM)is a thick,traditional Middle Eastern syrup used in many recipes for Lebanese and international cuisines.It is a highly nutritious product which makes it of great interest.The purpose of this study was to assess the phytochemical composition,antioxidant and anti-diabetic properties of homemade and commercial PM consumed in Lebanon using samples collected from households in rural areas(n=4)and the market(n=28).The objectives of this study were to determine their total phenolic content using the Follin-Ciocalteu method,their total flavonoid content using aluminum chloride method,their antioxidant activity using DPPH radical scavenging as well as ferrous ion chelating assays and their anti-diabetic activity usingα-amylase andα-glucosidase inhibitory activities with acarbose,a known anti-diabetic drug,used as the standard reference.Homemade PM samples exhibited a higher antioxidant activity than commercial samples,with the most active homemade PM sample having IC_(50)values of 0.09 mg/mL(DPPH radical scavenging assay)and 46.78%ferrous ion chelating assay).Homemade PM samples also showed higher anti-diabetic activity than commercial samples,with the most active homemade PM sample having an IC_(50)values of 0.63 mg/mL(α-amylase inhibitory activity)and of 0.41 mg/mL(α-glucosidase inhibitory activity)and being almost as active as acarbose with both enzymes(1.5 times).Significant inverse strong/moderate correlations were observed between total phenolic content/total flavonoid content and the IC_(50)value of DPPH radical scavenging assay,indicating positive associations between total phenolic and flavonoid contents and antioxidant activity.In addition,significant negative moderate correlations were observed between total phenolic/flavonoid contents andα-amylase inhibitory activity,indicating positive associations between total phenolic and flavonoid contents and anti-diabetic activity.

‘台农’、‘红芒’芒果果皮和果肉原花青素含量差异及其生物学活性评价

为了充分利用芒果资源,明确‘台农’、‘红贵妃’芒果果皮和果肉的原花青素含量及其抗氧化活性和乙酰胆碱酯酶抑制活性,以成熟期‘台农’、‘红贵妃’芒果果皮和果肉为实验材料,用甲醇提取原花青素,盐酸-香草醛法测定其含量。通过羟自由基(·OH)、DPPH自由基、ABTS自由基清除率测定其抗氧化活性,Ellman法确定其乙酰胆碱酯酶抑制活性。结果表明:‘台农’和‘红贵妃’芒果果皮中原花青素含量差异显著,‘红贵妃’果皮原花青素显著高于‘台农’果皮原花青素。同一品种中,果皮原花青素含量显著高于果肉原花青素。‘台农’果皮和果肉中的原花青素对·OH、DPPH自由基和ABTS+·等自由基的清除能力很强,且显著高于‘红贵妃’果皮和果肉中原花青素的自由基清除能力。但是‘台农’、‘红贵妃’果皮和果肉中的原花青素对乙酰胆碱酯酶均具有很强的抑制活性。研究结果表明不同芒果品种原花青素含量差异显著,抗氧化能力也不同,但是均具有良好的乙酰胆碱酯酶抑制活性。本研究为进一步探讨不同品种芒果原花青素生物学活性及其作用机理奠定了基础。

4种杀虫剂对马铃薯桃蚜的毒力及对其乙酰胆碱酯酶活性的影响

[目的]明确呼和浩特和武川2个地区马铃薯桃蚜抗药性水平并探寻其抗性形成机制。[方法]采用室内生物测定方法检测了4种杀虫剂对呼和浩特、武川马铃薯桃蚜种群和北京室内饲养的不接触任何药剂的桃蚜的毒力,并对各种群桃蚜的乙酰胆碱酯酶活性进行测定。[结果]呼和浩特和武川2个田间种群对毒死蜱抗性倍数分别为25.79和70.20,处于中高抗水平;对氧乐果的抗性倍数均小于5,处于敏感向抗性过渡阶段;对灭多威和异丙威的抗性水平较低,抗性倍数在3.86~6.88之间。乙酰胆碱酯酶活力与杀虫剂的抗性倍数成负相关性。对乙酰胆碱酯酶活性抑制试验中,毒死蜱对3个马铃薯桃蚜种群均有较强抑制作用。[结论]呼和浩特和武川地区马铃薯桃蚜体内乙酰胆碱酯酶靶标不敏感性已存在,建议两地区防治该种害虫时,交替轮换用药或选用复配剂。

New furo[3,2-h]isochroman from the mangrove endophytic fungus Aspergillus sp. 085242

Four new compounds, asperisocoumarin G(1), asperisocoumarin H(2),(±)-asperisocoumarin I [(±)-3], along with the known pergillin(4) and penicisochroman L(5) were isolated from a mangrove endophytic fungus Aspergillus sp. 085242 by further chemical investigation. The structures of the new compounds, including their absolute configurations, were established by analysis of HR-ESI-MS and NMR spectroscopic data, and ECD calculation. Asperisocoumarins G-I(1-3) were new isocoumarins belonging to the class of furo[3, 2-h]isocoumarins which are rarely found in natural sources. All of the isolated compounds were evaluated for theirα-glucosidase inhibitory effects, and compounds 1 and 4 showed moderate α-glucosidase inhibitory activity, respectively. In an antimicrobial test, the racemate of 3 showed antibacterial activity against Salmonella.

Three new isocoumarin derivatives from the mangrove endophytic fungus Penicillium sp. YYSJ-3

Three new isocoumarin derivatives,(S)-6,8-dihydroxy-5-(methoxymethyl)-3,7-dimethylisochroman-1-one(1),(S)-6,8-dihydroxy-3,5,7-trimethyl-isochroman-1-one(2) and(R)-2-chloro-3-(8-hydroxy-6-methoxy-1-oxo-1 H-isochromen-3-yl) propyl acetate(3), along with four known compounds(4–7) were isolated from a mangrove endophytic fungus Penicillium sp. YYSJ-3. Their structures were established on the basis of the extensive spectroscopic data and HR-ESI-MS analysis. The absolute configurations of1–3 were further determined by X-ray diffraction analysis and optical rotations. Compounds 3, 6 and 7 showed promising inhibitory activity against α-glucosidase, which were stronger than that of the positive control 1-deoxynojirimycin(IC50 141.2 μmol·L-1).