Chemical constituents from Ganoderma angustisporum and their α-glucosidase inhibitory activities / 中成药

AIM To study the chemical constituents from Ganoderma angustisporum J.H.Xing,B.K.Cui&Y.C.Dai and their α-glucosidase inhibitory activities.METHODS The ethyl acetate extract from G.angustisporum was isolated and purified by silica gel,ODS,TLC and HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.pNPG method was used to evaluate their α-glucosidase inhibitory activities.RESULTS Seven compounds were isolated and identified as N-acetyl-L-phenylalanine ethyl ester(1),N-acetyl-L-phenylalanine methyl ester(2),4-hydroxy-17R-methylincisterol(3),6,8-di-O-methylaverufin(4),aversin(5),methyl 2-(4-hydroxyphenyl)aceate(6),5-toluene-1,3-diol(7).Compounds 1-2,4-7 showed inhibitory activities of α-glucosidase with IC50 values being(33.80±0.47),(45.45±7.95),(48.80±5.86),(39.48±2.82),(41.47±6.68),(55.38±10.12)μmol/L,and compound 1 showed good inhibitory activity.CONCLUSION Compound 1 is a new natural product.Compounds 2-7 are isolated from genus Ganoderma for the first time.Compounds 1-2,4-7 have α-glucosidase inhibitory activities.

Secondary metabolites and their α-glucosidase inhibitory activity of endophyte fungi from Orixa japonica / 中成药

AIM To identify the endophytic fungus G-(JK)-2 from Orixa japonica Thunb.and to study its secondary metabolites and their α-glucosidase inhibitory activities.METHODS Through the ITS sequence,the evolutionary tree that identifies the endophytic fungus G-(JK)-2 was established.Then 45 days rice solid medium of endophytic fungus G-(JK)-2 was extracted by methanol,and then by ethyl acetate.The ethyl acetate extract was separated and purified by silica gel chromatography,Sephadex LH-20,and semi-preparative HPLC.The structures of obtained compounds were identified by physicochemical properties and spectral data.Their α-glucosidase inhibitory activities were evaluated by PNPG method.RESULTS The endophytic fungus G-(JK)-2 from O.japonica was identified as Fusarium nematophilum.Thirteen compounds were isolated and identified as p-hydroxybenzaldehyde(G1),4-hydroxyacetophenone(G2),anhydromevalonolactone(G3),flazine(G4),salicylic acid(G5),p-hydroxybenzoic acid(G6),di-(2-ethylhexyl)-phthalate(G7),terephthalic acid bis(2-ethyl-hexyl)ester(G8),thymine(G9),uridine(G10),adenosine(G11),2′-deoxyuridine(G12),nicotinic acid(G13).The inhibitory effect of each compound on α-glucosidase was in sequence of G4>G11>G10>G13>G12.CONCLUSION All compounds are first isolated from the endophytic fungi of the O.japonica,and G10,G11,G13 are first isolated from the endophytic fungi of Fusarium.G4 and G11 have mild inhibition to α-glucosidase.

Chemical constituents from the leaves of Cyclocarya paliurus and their α-glucosidase inhibitory activities / 中成药

AIM To study the chemical constituents from the leaves of Cyanocarya paliurus(Batalin)Iljinskaja and their α-glucosidase inhibitory activities.METHODS The 95%ethanol extract from the leaves of C.paliurus was isolated and purified by macroporous resin,silica gel,Sephadex LH-20,polyamide,C18 reversed-phase silica gel and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.Their α-glucosidase inhibitory activities were evaluated by PNPG.RESULTS Fifteen compounds were isolated and identified as cyclopaloside C(1),cyclopaloside A(2),juglanosides E(3),vaccinin A(4),ent-murin A(5),kaempferol 3-O-α-L-rhamnopyranoside(6),kaempferol-3-O-β-D-glucopyranoside(7),kaempferol-3-O-β-D-glucuronide methyl ester(8),kaempferol-3-O-β-D-glucuronide ethyl ester(9),kaempferol-3-O-β-D-glucuronide butyl ester(10),quercetin-3-O-α-L-rhamnopyranoside(11)quercetin-3-O-β-D-glucopyranoside(12),quercetin-3-O-β-D-galactopyranoside(13),quercetin-3-O-β-D-glucuronide butyl ester(14),dihydrokaempferol(15).The IC50 value of total extracts ihibited α-glucosidase was(1.83±0.04)μg/mL,and the IC50 values of compounds 1,4-5 were(29.48±1.86),(0.50±0.07),(0.71±0.07)μmol/L,respectively.CONCLUSION Compound 1 is a new tetrahydronaphthalene glycoside.Compounds 4-5,8-10 and 14 are isolated from the leaves of C.paliurus for the first time.Compounds 4-5 are relatively rare flavonoid lignans with potential inhibitory activities against α-glucosidase.

Bioassay-guided isolation of α-Glucosidase inhibitory constituents from Hypericum sampsonii / 中国天然药物

This study employed the α-glucosidase inhibitory activity model as an anti-diabetic assay and implemented a bioactivity-guided isolation strategy to identify novel natural compounds with potential therapeutic properties. Hypericum sampsoniiwas investigated, leading to the isolation of two highly modified seco-polycyclic polyprenylated acylphloroglucinols (PPAPs) (1 and 2), eight phenolic derivatives (3-10), and four terpene derivatives (11-14). The structures of compounds 1 and 2, featuring an unprecedented octahydro-2H-chromen-2-one ring system, were fully characterized using extensive spectroscopic data and quantum chemistry calculations. Six compounds (1, 5-7, 9, and 14) exhibited potential inhibitory effects against α-glucosidase, with IC50 values ranging from 0.050 ± 0.0016 to 366.70 ± 11.08 μg·mL-1. Notably, compound 5 (0.050 ± 0.0016 μg·mL-1) was identified as the most potential α-glucosidase inhibitor, with an inhibitory effect about 6900 times stronger than the positive control, acarbose (IC50 = 346.63 ± 15.65 μg·mL-1). A docking study was conducted to predict molecular interactions between two compounds (1 and 5) and α-glucosidase, and the hypothetical biosynthetic pathways of the two unprecedented seco-PPAPs were proposed.

Chemical constituents and their α-glucosidase inhibitory activities of seeds of Moringa oleifera / 中国中药杂志

The chemical constituents of the seeds of Moringa oleifera were isolated and purified by using Sephadex LH-20, Toyo-pearl HW-40F, silica gel, ODS, and MCI column chromatography. The structures of compounds were identified by high-resolution mass spectrometry, ~1H-NMR, ~(13)C-NMR, HMQC, HMBC, and ~1H-~1H COSY, as well as physicochemical properties of compounds and literature data. Twelve compounds were isolated from 30% ethanol fraction of the seeds of M. oleifera and identified as ethyl-4-O-α-L-rhamnosyl-α-L-rhamnoside(1), ethyl-3-O-α-L-rhamnosyl-α-L-rhamnoside(2),(4-hydroxybenzyl)ethyl carbamate(3),(4-aminophenyl)acetic acid(4), ethyl-α-L-rhamnoside(5), methyl-α-L-rhamnoside(6), moringapyranosyl(7), 2-[4-(α-L-rhamnosyl)phenyl]methyl acetate(8), niaziridin(9), 5-hydroxymethyl furfural(10), 4-hydroxybenzeneacetamide(11), and 4-hydroxybenzoic acid(12). Among them, compounds 1 and 2 are two new compounds, compound 3 is a new natural product, and compounds 4-5 were yielded from Moringa plant for the first time. All compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compound 10 showed excellent inhibitory activity with IC_(50) of 210 μg·mL~(-1).

Chemical constituents from Salacia polysperma / 中国中药杂志

Nine compounds were isolated from the 90% ethanol extract of Salacia polysperma by silica gel, Sephadex LH-20 column chromatography, together with preparative HPLC methods. Based on HR-ESI-MS, MS, 1D and 2D NMR spectral analyses, the structures of the nine compounds were identified as 28-hydroxy wilforlide B(1), wilforlide A(2), 1β,3β-dihydroxyurs-9(11),12-diene(3),(-)-epicatechin(4),(+)-catechin(5),(-)-4'-O-methyl-ent-galloepicatechin(6), 3-hydroxy-1-(4-hydroxy-3-methoxy-phenyl)propan-1-one(7),(-)-(7S,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneoligna-7,9-diol-7'-aldehyde(8), and vanillic acid(9). Compound 1 is a new oleanane-type triterpene lactone. Compounds 1, 3, 4, 7-9 were isolated from the Salacia genus for the first time. All compounds were assayed for their α-glucosidase inhibitory activity. The results suggested that compound 8 exhibited moderate α-glucosidase inhibitory activity, with an IC_(50) value of 37.2 μmol·L~(-1), and the other compounds showed no α-glucosidase inhibitory activity.

Research on hypoglycemic activity of Osmanthus fragrans var. thunbergii extract / 药学学报

This study aimed to assess the hypoglycemic activity, and in vitro inhibition of α-glucosidase, inhibition of the advanced glycation end products (AGEs), and total antioxidant capacity were used to clarify its bioactivity. Furthermore, the potential hypoglycemic active chemical constituents in the aqueous extract of Osmanthus fragrans var. thunbergii flower were characterized using high performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) method. The result showed that in vitro inhibition of α-glucosidase of the extract (IC50 = 2.11 ± 0.26 mg·mL-1) were similar to acarbose (IC50 = 2.88 ± 0.32 mg·mL-1), and it inhibited the AGEs formation and the total antioxidant capacity in a certain extent. Based on the MS fragmentation pathway analysis of reference chemical acteoside contained in this extract, and related references, 73 constituents were tentatively identified from the aqueous extract of Osmanthus fragrans var. thunbergii flower, including 58 phenylethanoids, 8 caffeoylquinic acids, 1 flavonoid vicenin-2, and 6 common organic chemicals in plant. Furthermore, 8 unknown alkaloids were characterized in this work. Among of these chemicals, 61 phenylethanoids were supposed to be detected for the first time. In conclusion, this work disclosed the potential hypoglycemic active constituents of Osmanthus fragrans var. thunbergii flower.

The chemical constituents and hypoglycemic activity of alcoholic extract of sea buckthorn leaves / 药学学报

The purpose of this research is to identify the chemical constituents of sea buckthorn leaves extract (SBLE) and explore its hypoglycemic biological activity. SBLE was prepared by hot reflux extraction with 65% ethanol, and its chemical composition was analyzed by ultra-high-performance liquid chromatography-photodiode array-mass spectrometry/mass spectrometry (UHPLC-PDA-MS/MS) system. The animal experiments were compliant with ethical principles for animal use and had been approved by the Animal Experiment Ethics Committee of Jinan University. Mice were injected with streptozocin (STZ) to establish a hyperglycemic animal model, and SBLE (1.5 g·kg-1) was administered by gavage for 5 weeks. The fasting blood glucose (FBG) and oral glucose tolerance were detected. Normal mice were given SBLE (1.5 g·kg-1) by intragastric administration for 10 days, and blood was collected from the tail vein to detect the changes in blood glucose within 120 min after sucrose or starch loading. The mucous membrane of the small intestine of mice was taken to detect the activity of α-glucosidase (AG), and the activity of yeast-derived AG incubated with SBLE was evaluated. The glucose uptake by Caco-2 cells treated with SBLE was detected by fluorescence microscopy and cytometry, and the gene expression of sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) in Caco-2 cells were detected by real-time quantitative PCR (qPCR). A total of 18 compounds were identified, mainly including tannins and flavonoids. SBLE reduced FBG and increased oral glucose tolerance in STZ hyperglycemic mice. SBLE effectively inhibited the increase of blood glucose caused by starch intake in normal mice. SBLE exerted good inhibitory activity on yeast-derived AG (IC50 = 16.94 μg·mL-1) and small intestinal mucosa AG with an inhibition rate of 15.48%. SBLE (25-100 μg·mL-1) dose-dependently inhibited glucose uptake by Caco-2 cells, and SBLE significantly reduced the mRNA level of SGLT1 without changing the expression of GLUT2. In conclusion, the UHPLC characteristic fingerprint of SBLE is established with 18 chemical components identified by mass spectrometry, and SBLE exerts hypoglycemic effect by inhibiting the activity of AG and the absorption of glucose by intestinal epithelial cells.

Inhibitory Effects of 41 Common Chinese Herbal Medicines on α-glucosidase and α-amylase in Meizhou Hakka / 医药导报

Objective Taking 41 kinds of Chinese herbal medicines commonly used in Meizhou Hakka as the research object,their inhibitory activities against α-glucosidase and α-amylase were screened and the enzyme inhibition types of the species with the strongest activities were explored.Methods The inhibitory activities of 41 commonly used Hakka herbs in Meizhou against α-glucosidase and α-amylase were evaluated by the p-Nitrophenyl a-D-mannopyranoside(pNPG)method and the 3,5-Dinitrosalicylic acid(DNS)method,using the inhibitory rate of half(IC50)as an index.The inhibitory activity of 95%ethanol extracts of 41 Chinese herbal medicines commonly used in Meizhou Hakka on α-glucosidase and α-amylase were analysed.The enzymatic kinetics method and Lineweaver-Burk curve were used to analyze the inhibitory type of the most active species.Results The results showed that 40 Chinese herbal medicines commonly used in Meizhou Hakka had α-glucosidase inhibitory activity,and 23 medicines had α-amylase inhibitory activity,among which Psychotria asiatica Wall.showed the strongest inhibitory activity with the IC50 values aganist α-glucosidase and α-amylase of 0.17±0.001 mg·mL-1 and 0.09±0.001 mg·mL-1,respectively.The inhibition types were reversible competitive inhibition and reversible non-competitive inhibition,respectively.Conclusion The Psychotria asiatica Wall.Chinese herbal medicines commonly used in Meizhou Hakka has significant inhibitory effect on the activity of glucose metabolism enzymes,which has potential value for further research and development on the prevention and treatment of diabetes mellitus.

Clinical and genetic features of 12 families with Pompe disease / 中华神经医学杂志

Objective:To investigate the clinical and genetic features of Pompe disease, and analyze the effect of enzyme replacement therapy on it.Methods:A retrospective study was performed. The clinical data and genetic results of 14 patients with Pompe disease from 12 families, admitted to our hospital from January 2017 to June 2021, were collected. Some patients were followed up after therapies.Results:Twelve of the 14 patients were late onset, with onset age ranged from 1.5 to 37.0 years (mean 15.2 years), and the other 2 patients were infantile onset. The predominant manifestations included proximal lower limb weakness, accompanied by easy fatigue and myalgia; 8 patients presented with dyspnea, of which one had dyspnea as initial presentation. Serum creatine kinase ranged from 172 to 1397 IU/L (mean 878 IU/L). Electromyography revealed myogenic pattern in 6 patients and myotonic discharge in 4 patients. Forced vital capacity decreased in 10 patients, and scoliosis was detected in 5 patients; 13 patients had decreased acid-alpha-glucosidase (GAA) activity; muscle pathology indicated vacuolar myopathy in 8 patients. Genetic test revealed 17 variants in GAA gene, among which c.2331G>C, c.1622C>T, c.1585T>C, and c.1837T>C were 4 novel likely pathogenic variants. The c.2238G>C and c.2662G>T were found in 5 and 3 families, respectively. Muscle strength and lung function got improvement in 1 patient who received enzyme replacement therapy and had regular follow-up, while muscle strength and lung function were worsened in those who did not receive enzyme replacement therapy. Conclusions:Pompe disease is characterized by skeletal muscle weakness and pulmonary dysfunction, and may be associated with spinal deformity; creatine kinase is mildly to moderately elevated, and myotonic discharge can be detected. GAA c.2238G>C and c.2662G>T are hotspot mutations in China; the 4 novel variants enrich the GAA mutational spectrum. Enzyme replacement therapy may improve motor and pulmonary function.

Study on chemical constituents of sponge-associated Aspergillus terreus / 药学实践杂志

Objective To study the chemical constituents of Aspergillus terreus from sponge epiphytic fungal. Methods Sephadex LH-20 column chromatography, silica gel column chromatography and high performance liquid chroma-tography were used to separate and purify the compounds. The structures of compounds were identified by spectroscopic data. The α-glucosidase inhibitory activity and antioxidant activity of the compounds were tested by PNPG and DPPH methods, respectively. Results Eight compounds were isolated from Aspergillus terreus and identified as methyl-3,4,5-trimethoxy-2-(2-(nicotinamido) benzamido) benzoate (1), terrelumamide A (2), emeheterone (3), (8R,9S)-dihydroisoflavipucine (4), (8S,9S)-dihydroisoflavipucine (5), cyclo(S-Pro-S-Phe) (6), brevianamide F (7), terrein (8). Compound 3 showed strong inhibitory activity against α-glucosidase and the IC50 value was 14.28 μmol/L. Conclusion Compounds 3, 4, 5, and 7 were obtained from Aspergillus terreus for the first time.

Establishment of high-resolution bioassay profiling platform to screen α-glucosidase inhibitors from Malus hupehensis / 药学学报

italic>α-Glucosidase inhibitors play an important role in the treatment of diabetes. This study established a high-resolution bioassay profiling platform for rapidly screening α-glucosidase inhibitors in natural product extracts. Five α-glucosidase inhibitors were identified from Malus hupehensis, namely, 3-hydroxyphloridzin, quercetin-3-O-β-D-glucopyranoside, phloridzin, avicularin and quercitrin. The establishment and successful application of this platform provides a powerful tool for the efficient discovery of anti-diabetic active ingredients in complex systems.

Chemical composition and hypoglycemic activity of Edgeworthia gardneri / 药学学报

Seven compounds were isolated from the alcohol extract of Edgeworthia gardneri by various technologies, including silica gel, Sephadex LH-20 and high performance liquid chromatography, and were identified as edgeworthiaside A (1), 2,4,6-trichlorol-3-methyl-5-methoxy-phenol 1-O-β-D-glucopyranosyl-(1-6)-β-D-glucopyranoside (2), 2,6-dimethoxy-4-(2-propen-1-yl)phenyl 6-O-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranoside (3), eugenol rutinoside (4), tiliroside (5), edgeworoside C (6), and salicylic acid (7). Compound 1 is a new chlorophenyl glycoside and 2-4 were isolated for the first time from Edgeworthia gardneri. The in vitro inhibition of α-glucosidase showed that the inhibition rate of compounds 1 and 2 were similar to acarbose.

Effect of Tartary Buckwheat Boiled Noodles on Postprandial Blood Glucose Level and Its Active Components / 日本補完代替医療学会誌

Dry solid matter (rutin content: 51.6 mg/g; quercetin content: 72.2 mg/g) extracted from Tartary buckwheat boiled noodles using 70% methanol as the solvent was found to have α-glucosidase inhibitory activity. As for fractions fractionated by silica gel column chromatography, the fractions rich in quercetin and rutin showed remarkable α-glucosidase inhibitory activity. Tartary buckwheat boiled noodles used as samples in this study contained quercetin produced from rutin by the action of rutinase, suggesting that both rutin and quercetin contained were involved in the α-glucosidase inhibitory activity of the dry solid extract. Changes in postprandial blood glucose levels were compared for boiled noodles made from two types of buckwheat (i.e., Tartary buckwheat and common buckwheat), revealing that blood glucose elevation after eating Tartary buckwheat boiled noodles was suppressed. The blood glucose level 40 minutes after eating Tartary buckwheat boiled noodles was significantly low (p<0.05). It can be concluded that this might be caused by the α-glucosidase inhibitory activity of rutin (270.0 mg) and quercetin (330.5 mg), which correspond to a total amount of 935 mg of rutin equivalents, in the gastrointestinal tract. As a result, the digestion of carbohydrates contained in the samples consumed and their absorption by the intestine might be inhibited, resulting in the suppression of increases in blood glucose levels. The presence of a certain amount of quercetin was considered to be key to the suppression of blood glucose elevation. It is important to control rapid postprandial blood glucose increases to prevent diabetes from developing or becoming serious. This study suggests the potential for Tartary buckwheat boiled noodles to contribute to diabetes prevention.

Comparative of functional components, antioxidant and α-glucosidase inhibition activities between Choerospondias axillaris fruit peel vinegar and apple vinegar / 中国中药杂志

Based on the idea of plant metabolomics, ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) was used to compare the chemical composition between 6 batches of fruit vinegar brewed from Choerospondias axillaris fruit peel and 6 batches of apple vinegar purchased from 3 companies. Antioxidant and α-glucosidase inhibition activities were also tested in vitro. A total of 43 compounds were identified by reference substance, liquid chromatography-mass spectrometry(LC-MS/MS) fragmentation information or literature data. A total of 40 compounds were identified in the C. axillaris fruit peel vinegar. A total of 16 compounds were identified in apple vinegar. There were 13 common ingredients including organic acids and esters such as citric acid, 2-isopropyl malic acid, and triethyl citrate. The results of partial leastsquares-discriminant analysis(PLS-DA) indicated that they had 33 significantly different compounds such as proanthocyanidin oligomer, quercetin-3-O-rhamnoside and heptadecanoic acid. The proanthocyanidins and flavonoid glycosides in C. axillaris peel vinegar were more abundant than apple vinegar, so it had better health function than ordinary fruit vinegar. The results showed that C. axillaris fruit peel vinegar had stronger antioxidant and α-glucosidase inhibition activities in vitro. The vinegar brewed from waste C. axillaris fruit peel had more chemical ingredients than the apple vinegar. C. axillaris fruit peel vinegar had better biological activity and health function, so it had good development prospect. This study provided the scientific evidence for exploiting the C. axillaris fruit peel into high value-added products. It also provided ideas for the comprehensive development and utilization of similar Chinese medicine waste.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective: To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum. Methods: The effects of oral treatment with hydro-ethanolic extract (125, 250 and 500 mg/kg) of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level, serum enzyme markers for liver function, lipid profile, total protein, serum urea, serum creatinine, and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin. In vitro assays including glucose uptake in C2C12 cells and 3T3-L1 adipose tissues, α-glucosidase and α-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract. DPPH and nitric oxide radical antioxidant activity of the extract was also measured. Results: The increased levels of blood glucose, triglycerides, low-density lipoprotein, total cholesterol, serum aspartate, and alanine transaminases, creatinine, and urea in the diabetic animals were reduced significantly (P<0.01) after treatment with Chrysophyllum albidum extract. The decreased total protein and high-density lipoprotein concentrations were normalized after treatment. In addition, the extract significantly (P<0.01) increased the transport of glucose in 3T3-L1 cells and C2C12 myotubes and exhibited considerable potential to inhibit α-amylase and α-glucosidase. It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals. Conclusions: Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2C12 myotubes and 3T3-L1 adipocytes as well as inhibiting the activities of α-amylase and α-glucosidase.

New furo3,2-hisochroman from the mangrove endophytic fungus Aspergillus sp. 085242 / 中国天然药物

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 their α-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.

Fingerprint Establishment ，Content Determination and α-glucosidase Inhibitory Activity Study of Polysaccharide from Desmodium styracifolium / 中国药房

OBJECTIVE：To estab lish the fingerprint ，analyze the monosaccharide composition and content ，investigate the inhibitory effects of the polysaccharide from Desmodium styracifolium on α-glucosidase in vitro . METHODS ：Polysaccharide from D. styracifolium was prepared by water extraction and ethanol precipitation. After hydrolyzed by TFA and derived by PMP ，HPLC method was adopted to establish the fingerprint （using glucose peak as reference ），and analyze the constituent and content of monosaccharide. The content determination was performed on Phenomenex Luna C 18 column with mobile phase consisted of acetonitrile-0.05 mol/L potassium phosphate （pH adjusted to 6.8 with sodium hydroxide ）in gradient elution at the flow rate of 0.8 mL/min. The detection wavelength was set at 250 nm，and column temperature was set at 30 ℃. The sample size was 10 μL. Using acarbose as control ，PNPG assay was used to investigate the α-glucosidase inhibitory activity of polysaccharide from D. styracifolium. RESULTS ：There were 9 common peaks in HPLC fingerprints of 18 batches of samples ，and the similarity of 15 batches of samples was higher than 0.90. Totally 7 peaks were identified as mannose ，rhamnose，galacturonic acid ，glucose， galactose，xylose and arabinose. The contents of rhamnose ，galacturonic acid ，glucose，galactose and arabinose were 0.471-2.092， 1.379-8.919，2.560-35.679，1.194-6.905，0.566-4.158 mg/g，respectively. Based on rhamnose ，the molar ratios of the other four monosaccharides were 1.58-4.07，2.26-19.95，2.20-4.21 and 1.31-2.86，respectively. The inhibitory activity of polysaccharide from D. styracifolium on α-glucosidase increased with the increase of dose ，and the half inhibitory concentrations of it was 0.70 mg/mL， lower than 7.76 mg/mL of acarbose （positive control ）. CONCLUSIONS ：Glucose is the main component of D. styracifolium polysaccharide in different batches ，and the contents of monosaccharides are different. The polysaccharide from D. styracifolium have significant inhibitory activity on α-glucosidase，which is better than that of acarbose.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective: To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum. Methods: The effects of oral treatment with hydro-ethanolic extract (125, 250 and 500 mg/kg) of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level, serum enzyme markers for liver function, lipid profile, total protein, serum urea, serum creatinine, and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin. In vitro assays including glucose uptake in C2C12 cells and 3T3-L1 adipose tissues, α-glucosidase and α-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract. DPPH and nitric oxide radical antioxidant activity of the extract was also measured. Results: The increased levels of blood glucose, triglycerides, low-density lipoprotein, total cholesterol, serum aspartate, and alanine transaminases, creatinine, and urea in the diabetic animals were reduced significantly (P<0.01) after treatment with Chrysophyllum albidum extract. The decreased total protein and high-density lipoprotein concentrations were normalized after treatment. In addition, the extract significantly (P<0.01) increased the transport of glucose in 3T3-L1 cells and C2C12 myotubes and exhibited considerable potential to inhibit α-amylase and α-glucosidase. It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals. Conclusions: Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2C12 myotubes and 3T3-L1 adipocytes as well as inhibiting the activities of α-amylase and α-glucosidase.

Triterpenoids from Gynostemma pentaphyllum and their inhibition activity to α-glycosidase and protein tyrosine phosphatase 1B / 中草药

Objective: To determine the total saponins from Gynostemma pentaphyllum, the dammarane-type triterpenoids of its hydrolysate, and its hypoglycemic activity. Methods: Compounds from the acid hydrolyzate extracts and total saponins were isolated by silica gel, recrystal and preparative liquid chromatography, and their structures were identified by the NMR spectral analysis. The sensitive screening modles of α-glucosidase and PTP1B inhibitors were established in vitro. The inhibitory kinetics of compounds were also investigated. Using the method of computer aided drug design of active site, PTP1B interact with the strongest active compound for docking simulation. Results: Seven compounds were isolated from the acid hydrolyzate of total saponins, which identified as gpsapogenin A (1), 20(S)-panaxadiol (2), gypensapogenin F (3), 20(R)-protopanaxadiol (4), (23S)-3β- hydroxydama-20,24-diene-21-carboxylic acid 21,23-lactone (5), gypsapogenin A (6), and (20S,24S)-3β,20,21β,23β,25- pentahydroxy-21,24-epoxydammarane (7). Five compounds were isolated from total saponins, including (20R,23R)- 3β,20-dihydroxydammar-24-en-21-oic acid 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-6-O- acetyl-β-D-glucopyranoside (8), (20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-6-O-acetyl-β-D-glucopyranoside (9), (20R,23R)-19-oxo-3β,20-dihydroxydammar-24-en-21-oci acid 21,23-lactone3-O-[α-L-rhamnopyranosyl-(1→2)][β-D-xylopyranosyl(1→3)]-α-L-arabinopyranoside (10), (20S)-3β,20,21- trihydroxydammar-23,25-diene 3-O-{[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl(1→3)]-β-D-glucopyranosyl}-21-O-β- D-glucopyranoside (11), and (20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid and 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)][β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (12). Conclusion: Beside compound 4, the other compounds showed inhibitory activity against α-glucosidase and PTP1B. For the α-glucosidase and PTP1B inhibitions assay, compound 9 indicated the strongest inhibitory effect with IC50 2.10 and 1.07 μmol/L, respectively.