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.

Antioxidant potential and alfa-glucosidase inhibitory activity of onion (Allium cepa L. ) peel and bulb extracts / Atividade antioxidante e potencial inibidor de alfa-glucosidase de extratos de casca e bulbo de cebola (Allium cepa) preparados por etanol e água

Allium cepa L. is a commonly consumed vegetable that belongs to the Amaryllidaceae family and contains nutrients and antioxidants in ample amounts. In spite of the valuable food applications of onion bulb, its peel and outer fleshy layers are generally regarded as waste and exploration of their nutritional and therapeutic potential is still in progress with a very slow progression rate. The present study was designed with the purpose of doing a comparative analysis of the antioxidant potential of two parts of Allium cepa, i.g., bulb (edible part) and outer fleshy layers and dry peels (inedible part). Moreover, the inhibitory effect of the onion bulb and peel extracts on rat intestinal α-glucosidase and pancreatic α-amylase of porcine was also evaluated. The antioxidant potential of onion peel and bulb extracts were evaluated using 2,2-diphenyl- 1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power assay (FRAP), 2,2’-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, H2O2 radical scavenging activity and Fe2+ chelating activity. Total flavonoids and phenolic content of ethanolic extract of onion peel were significantly greater as compared to that of onion bulb. Ethanolic extract of onion peel also presented better antioxidant and free-radical scavenging activity as compared to the ethanolic extract of bulb, while the aqueous extract of bulb presented weakest antioxidative potential. Onion peel extract's α-glucosidase inhibition potential was also correlated with their phenolic and flavonoid contents. The current findings presented onion peel as a possible source of antioxidative agents and phenolic compounds that might be beneficial against development of various common chronic diseases that might have an association with oxidative stress. Besides, outer dry layers and fleshy peels of onion exhibited higher phenolic content and antioxidant activities, compared [...].

Allium cepa pertence à família Liliaceae e é rica em nutrientes e antioxidantes. Apesar das expressivas aplicações alimentares do bulbo da cebola, sua casca e outras camadas externas são geralmente consideradas resíduos, e seu potencial nutricional e terapêutico ainda é pouco explorado. O presente estudo foi delineado com o objetivo de investigar comparativamente o potencial antioxidante de duas partes de Allium cepa, por exemplo o bulbo (parte comestível) e camadas externas e cascas secas (parte não comestível). Além disso, o efeito inibitório dos extratos do bulbo de cebola e casca sobre a α-glucosidase intestinal de ratos e α-amilase pancreática suína também foi avaliado. O potencial antioxidante dos extratos da casca de cebola e bulbo foi avaliado utilizando-se 2,2-difenil-1-picrilhidrazil (DPPH), método de poder antioxidante de redução do ferro (FRAP), método 2,2’-azino-bis-3-etilbenzotiazolina-6-ácido sulfônico (ABTS) de eliminação de radicais, atividade de eliminação de radicais H2O2 e atividade quelante do Fe2+. Os flavonoides totais e os teores fenólicos do extrato de etanol da casca de cebola foram significativamente maiores quando comparados ao do bulbo. O extrato de etanol da casca de cebola também apresentou melhor atividade antioxidante e eliminação de radicais livres quando comparado ao extrato de etanol do bulbo, enquanto o extrato aquoso de bulbo apresentou menor potencial antioxidante. O potencial de inibição da α-glicosidase dos extratos de casca de cebola correlacionou-se com seus teores fenólicos e de flavonoides. Os resultados encontrados identificaram que a casca de cebola é uma possível fonte de agentes antioxidantes e compostos fenólicos que podem ser benéficos contra o desenvolvimento de várias doenças crônicas que estão associadas ao estresse oxidativo. Além disso, as camadas externas secas e as cascas da cebola exibiram maior conteúdo fenólico e atividades [...].

Bioactive phenolic compounds and organic acids in the decoction of fruits and leaves of Schinus areira L / Compuestos fenólicos bioactivos y ácidos orgánicos en la decocción de frutos y hojas de Schinus areira L

Leaf and fruit decoctions of Schinus areira L. from northwest Argentina were investigated here. Phenolic compounds and organic acids were analyzed by HPLC. Antioxidant capacity and α-glucosidase inhibition were determined by using in vitro tests. The general toxicity was assessed against Artemia salina nauplii. Hyperoside and 3 O-caffeoylquinic acid in leaf decoctions; gallic acid and catechin in fruit decoction were the major phenolic compounds. Malic and citric acids were the main organic acid quantified in the leaf and fruit decoctions, respectively. Fruit decoction had a relatively important content of shikimic acid, precursor of Tamiflu. Leaf decoction presents a greater richness in bioactive compounds with antiradical activity against DPPH●, O2●-and ●NO radicals. S. areira leaves and fruits had α-glucosidase inhibitory activity comparable to hyperoside and acarbose. Fruit decoction was not eco-toxic; leaf decoction showed significant eco-toxic activity and could be chosen for the search of other bioactive compounds with pharmacological activity.

Se investigaron decocciones de hojas y frutos de Schinus areira L. del noroeste de Argentina. Compuestos fenólicos y ácidos orgánicos se analizaron mediante HPLC. Capacidad antioxidante e inhibición de α-glucosidasa se determinaron in vitro. Se evaluó toxicidad general con Artemia salina. Los principales compuestos fenólicos fueron hiperósido y ácido 3 O-cafeoilquínico en hojas y ácido gálico y catequina en frutos. Los principales ácidos orgánicos cuantificados fueron málico en hojas y cítrico en frutos. Ácido shikímico, precursor del Tamiflu está presente en decocción de frutos con un contenido relativamente importante. La de hojas presenta una mayor riqueza en compuestos bioactivos con actividad antirradicalaria frente a DPPH●, O2●-y ●NO. Las hojas y frutos de S. areira tenían una actividad inhibidora de la α-glucosidasa comparable a la de hiperósido y acarbosa. La decocción de frutas no fue eco-tóxica, pero sí la de hojas que podría ser fuente de compuestos bioactivos con actividad farmacológica.

Inhibition of α-glucosidase, pancreatic lipase, and antioxidant property of Myrcia hatschbachii D. Legrand containing gallic and ellagic acids / Inhibición de la α-glucosidasa, la lipasa pancreática y la propiedad antioxidante de Myrcia hatschbachii D. Legrand que contiene ácidos gálico y elágico

Several species of the Myrcia genus have been used in folk medicine to treat diabetes. Therefore, the aim of this work was to investigate the inhibitory activity of α-glucosidase and pancreatic lipase in the crude extract (EBF) and in the ethyl acetate fraction (FFA) of Myrcia hatschbachii, as well as to identify isolated phenolic compounds and to evaluate the antioxidant property and preliminary in vitro toxicity against Artemia salina. EBF (IC50: 3.21 µg/mL) and FFA (IC50: 1.14 µg/mL) showed inhibitory activity superior to acarbose (IC50: 193.65 µg/mL). In addition, they showed inhibitory effects of pancreatic lipase (IC50: 556.58 µg/mL for EBF and 532.68 µg/mL for FFA), antioxidant potential, absence of preliminary toxicity and presence of gallic andellagic acids in FFA. The relevant results in the inhibition of α-glucosidase and pancreatic lipase motivate new studies for the development of herbal medicines that assist in the treatment of diabetic patients.

Varias especies del género Myrcia se han utilizado en la medicina popular para tratar la diabetes. Por lo tanto, el objetivo de este trabajo fue investigar la actividad inhibitoria de la α-glucosidasa y la lipasa pancreática en el extracto crudo (EBF) y en la fracción de acetato de etilo (FFA) de Myrcia hatschbachii, así como identificar compuestos fenólicos aislados y evaluar la propiedad antioxidante y toxicidad in vitro preliminar contra Artemia salina. EBF (IC50: 3.21 µg/mL) y FFA (IC50: 1.14 µg/mL) mostraron una actividad inhibitoria superior a la acarbosa (IC50: 193.65 µg/mL). Además, mostraron efectos inhibitorios de la lipasa pancreática (IC50: 556.58 µg/mL para EBF y 532.68 µg/mL para FFA), potencial antioxidante, ausencia de toxicidad preliminar y presencia de ácidos gálico y elágico en FFA. Los resultados relevantes en la inhibición de la α-glucosidasa y la lipasa pancreática motivan nuevos estudios para el desarrollo de medicamentos a base de hierbas que ayudan en el tratamiento de pacientes diabéticos.

Aportes de la biotecnología al diagnóstico y tratamiento de la enfermedad renal crónica y comorbilidades frecuentes / Biotechnology contribution to the diagnosis and treatment of chronic kidney disease and frequent comorbidities

Este trabajo tiene como objetivo revisar las contribuciones de la biotecnología, en relación con el tratamiento, diagnóstico y la monitorización de la enfermedad renal crónica (ERC) y sus comorbilidades más frecuentes, especialmente la anemia. En relación con los tratamientos, enfocamos el desarrollo de productos biofarmacéuticos como los agentes estimulantes de la eritropoyesis (ESA), que fueron los primeros biofármacos utilizados para el tratamiento de la anemia asociada a la ERC; analizamos sus características y utilización actual después de varios años de experiencia clínica, así como también otras alternativas en desarrollo. Revisamos distintos tipos de bioterapias, la utilización de las células estromales mesenquimales de médula ósea (MSC) y tratamientos alternativos con modificaciones dietarias, que se basan en la asociación entre la microbiota intestinal de los pacientes renales crónicos y sus condiciones fisiopatológicas. Finalmente, en relación con el diagnóstico y monitorización, nos referimos al estudio y validación de biomarcadores diagnósticos, predictivos y terapéuticos que han permitido optimizar los resultados clínicos en este tipo de pacientes. (AU)

The aim of this work is to review the contributions of biotechnology, in relation to the treatment, diagnosis and monitoring of chronic kidney disease (CKD) and its most frequent comorbidities, especially anemia. Regarding the treatment, we focus on the development of biopharmaceutical products such as erythropoiesis stimulating agents (ESA), which were the first biopharmaceuticals used to treat anemia associated with chronic kidney disease (CKD). We analyzed their characteristics and their current use after several years of clinical experience, as well as other alternatives in development. We also review different types of biotherapies, the use of bone marrow mesenchymal stromal cells (MSC) and alternative treatments with dietary modifications, which are based on the association between the intestinal microbiota of chronic kidney patients and their pathophysiological conditions. Finally, in relation to diagnosis and monitoring, we refer to the study and validation of diagnostic, predictive and therapeutic biomarkers that have made clinical results possible to be optimized in this type of patient. (AU)

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.

Phenolic compounds from Virola venosa (Myristicaceae) and evaluation of their antioxidant and enzyme inhibition potential / Compostos fenólicos de Virola venosa (Myristicaceae) e avaliação de seu potencial antioxidante e de inibição enzimática

Virola venosa, popularly known in Brazil as ucuuba-da-mata, occurs naturally in the Amazon region and has potential to provide useful natural compounds, as already known for other Virola species. Therefore, the objective of this study was to determine the chemical composition of bark and leaf extracts of V. venosa, and to test the antioxidant capacity and α-glucosidase inhibition potential of their compounds. Polar extracts showed to be more active in both assays, therefore a bioactivity-guided fractionation was performed to identify the compounds that were responsible for the recorded activities. Using a combination of LC-MS/MS analysis and isolation with NMR identification, eight phenolic compounds were identified. Assays with pure compounds of the active fraction revealed that ferulic acid was the main contributor compound to the observed bioactivity in the crude extracts. (AU)

Virola venosa, popularmente conhecida como ucuuba-da-mata, ocorre naturalmente na região amazônica e tem potencial para fornecer compostos naturais úteis, como já foi mostrado para outras espécies de Virola. Por isso, o objetivo deste estudo foi determinar a composição química dos extratos do tronco e das folhas de V. venosa e os possíveis potenciais antioxidantes e de inibição contra α-glucosidase de seus compostos. Os extratos polares mostraram-se mais ativos em ambos os testes, portanto, um fracionamento guiado por bioatividade foi realizado para designar os compostos responsáveis pelas atividades registradas. Através da combinação de análise CL-EM/EM e isolamento com identificação por RMN, foram identificados oito compostos fenólicos. Testes com os compostos puros principais das frações mais ativas indicaram o ácido ferúlico como o principal contribuinte das atividades biológicas observadas para os extratos brutos, e, consequentemente, o princípio ativo principal de V. venosa.(AU)

Synthesis of new 2-{2,3-dihydro-1, 4-benzodioxin-6-yl[(4-methylphenyl) sulfonyl]amino}-N-(un/substituted-phenyl)acetamides as α-glucosidase and acetylcholinesterase inhibitors and their in silico study

The aim of the present research work was to investigate the enzyme inhibitory potential of some new sulfonamides having benzodioxane and acetamide moieties. The synthesis was started by the reaction of N-2,3-dihydrobenzo[1,4]-dioxin-6-amine (1) with 4-methylbenzenesulfonyl chloride (2) in the presence of 10% aqueous Na2CO3 to yield N-(2,3-dihydrobenzo[1,4]-dioxin-6-yl)-4-methylbenzenesulfonamide (3), which was then reacted with 2-bromo-N-(un/substituted-phenyl)acetamides (6a-l) in DMF and lithium hydride as a base to afford various 2-{2,3-dihydro-1,4-benzodioxin-6-yl[(4-methylphenyl)sulfonyl]amino}-N-(un/substituted-phenyl)acetamides (7a-l). All the synthesized compounds were characterized by their IR and 1H-NMR spectral data along with CHN analysis data. The enzyme inhibitory activities of these compounds were tested against a-glucosidase and acetylcholinesterase (AChE). Most of the compounds exhibited substantial inhibitory activity against yeast a-glucosidase and weak against AChE. The in silico molecular docking results were also consistent with in vitro enzyme inhibition data.

A new eudesmane type sesquiterpene from cultivated Clerodendranthus spicatus in Hainan / 中国中药杂志

Six compounds were isolated from the aerial part of cultivated Clerodendranthus spicatus in Hainan with various chromatographic techniques,and their structures were determined as:1-dehydroxy-1-oxo-rupestrinol(1),N-trans-feruloyltyramine(2),methyl 3,4-dihydroxyphenyllactate(3),caffein acid(4),methyl caffeate(5) and ethyl caffeate(6),via analysis of physicochemical properties and spectroscopic evidence.Compound 1 was a new compound,while compounds 2 and 3 were isolated from C.spicatus for the first time.Biological activity results showed that compounds 2-4 exhibited α-glucosidase inhibitory activity with different inhibition ratio.

Study on chemical constituents from fruiting bodies of Ganoderma australe / 中国中药杂志

Chemical constituents were isolated from the fruiting bodies of Ganoderma australe by various column chromatographic techniques and HPLC method, and their chemical structures were identified through the combined analysis of physicochemical properties and spectral data. Meanwhile, their α-glucosidase inhibitory activity and anti-oxidative ability were evaluated. Seven compounds were isolated from G. australe and were identified as 6-methoxyl-cyclo-(Phe-Ile)(1), applanoxidic acid A methyl ester(2), ergosta-7,22 E-dien-3β-ol(3), cinnamic acid(4), 5α,8α-epidioxy-(20S,22E,24R)-ergosta-6,22-diene-3β-ol(5), 1-(3, 4-dihydroxyphenyl) ethanone(6), salicylic acid(7) and benzoic acid(8). Among the compounds, compound 1 was a new cyclic dipeptide. Compound 2 was a new lanosta natural product, and compounds 4, 6, 7 and 8 were obtained from G. australe for the first time. Moreover, compounds 4 and 8 exhibited α-glucosidase inhibitory activity with inhibition rates of 36.8% and 34.7%, and compounds 4, 7 and 8 had a certain activity in DPPH free radical scavenging activity with IC_(50) values of 0.168, 0.458 and 0.170 g·L~(-1), respectively. The DPPH radical scavenging rate of compound 1 was 41.1%.

New octadecanoid derivatives from the seeds of Ipomoea nil / 中国天然药物

Four new octadecanoid derivatives (1-4) including a pair of enantiomers (1/2), along with 12 known analogues (5-16), were isolatedfrom the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better α-glucosidase inhibitory activity than the positive control acarbose (IC 167.7 ± 1.55 μmol·L), with IC of 92.73 ± 3.12 and 11.39 ± 2.18μmol·L, respectively.

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

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, (2R, 3R)-(+)-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.

Inhibición de la a-amilasa por medio de extractos de plantas medicinales como tratamiento complementario/alternativo de la diabetes y la caries / Inhibition of a a-amylase by means of extracts of medicinal plants as complementary/alternative treatment of diabetes and caries

Los inhibidores selectivos de la α-amilasa salival y pancreática humana, son un medio eficaz para controlar los niveles de azúcar en la saliva y la sangre, durante el control de la caries y la diabetes. En la presente revisión, después de identificar las principales funciones de la enzima, se discutieron exponen algunas de las respuestas observadas después de la exposición de la α-amilasa a las plantas, en escala molecular y entera. Diferentes tipos de moléculas de plantas medicinales actúan como inhibidores de la α-amilasa, como una terapia alternativa o complementaria en el tratamiento de la diabetes en y en el control de uno de los factores de la formación la caries (dieta) (AU)

Selective inhibitors of human salivary and pancreatic α-amylase are an effective means of controlling saliva and blood sugar levels in the management of caries and diabetes. In the present review, after identifying the main functions of the enzyme, it was exposed some of the observed responses after exposure to α-amylase at the molecular and whole plants scale. Different types of medicinal plants molecules have been found to act as α-amylase inhibitors, as an alternative or complementary therapy in the management of diabetes and control to one of the predisposing factors to caries (diet) (AU)

Identification and preparation of a glycol-protein fraction AN from tea extracts and its and anti-hyperglycosemia activity / 中国中药杂志

The present study compared active ingredients of tea from different sources to select tea type and the fraction of tea extracts for the highest anti-hyperglycemic activity, and to verify anti-hyperglycemic activity of the selected tea extract. Tea extracts were separated and enriched by molecular weight using ultra-filtration technology. The extracts were first screened by -glucosidase inhibition assay, followed by using a rat inverted intestine sac system to measure the effect on glucose transport. Both alloxan-induced diabetic rat model and high-fat diet combined with streptozotocin-induced rat diabetes mellitus model were used to study the effects of active components on blood glucose, body weight, insulin resistance. The experimental results showed that the different kinds of tea extracts had different inhibitory effects on -glucosidase, and the inhibitory effect of tea extract E on -glucosidase was stronger. The effects of different components of tea extract E also varied greatly, of which Fraction AN protein had stronger inhibitory effect on -glucosidase than other fragments, and Fraction AN protein had a strong inhibitory effect on glucose transport, reduced blood sugar and normalized insulin secretion in diabetic rats. The results suggest that a glycol-protein fraction(AN) from the extracts might be responsible for the anti-hyperglycemic activity of tea polysaccharides. The AN glycol-protein fraction has strong inhibitory effects on both -glucosidase activity and glucose transport by the small intestine. It also reduced blood glucose level and normalized insulin secretion in diabetic rats, and has a protective effect on diabetic rats.

Inhibitory potentials of phenolic-rich extracts from Bridelia ferruginea on two key carbohydrate-metabolizing enzymes and Fe-induced pancreatic oxidative stress / 中西医结合学报

<p><b>OBJECTIVE</b>The current study was designed to evaluate the various antioxidant potentials and inhibitory effects of phenolic-rich leaf extracts of Bridelia ferruginea (BF) on the in vitro activities of some key enzymes involved in the metabolism of carbohydrates.</p><p><b>METHODS</b>In this study, BF leaf free and bound phenolic-rich extracts were used. We quantified total phenolic and flavonoid contents, and evaluated several antioxidant activities using assays for ferric reducing antioxidant power, total antioxidant activity (phosphomolybdenum reducing ability), 1,1-diphenyl-2-picrylhydrazyl and thiobarbituric acid reactive species. Also, extracts were tested for their ability to inhibit α-amylase and α-glucosidase activity.</p><p><b>RESULTS</b>The total phenolic and total flavonoid contents in the free phenolic extract of BF were significantly greater than in the bound phenolic extract. Also, all the antioxidant activities considered were significantly greater in the free phenolic extract than in the bound phenolic extract. In the same vein, the free phenolic-rich extract had a significantly higher percentage inhibition against α-glucosidase activity (IC = 28.5 µg/mL) than the bound phenolic extract (IC = 340.0 µg/mL). On the contrary, the free phenolic extract (IC = 210.0 µg/mL) had significantly lower inhibition against α-amylase than the bound phenolic-rich extract (IC = 190.0 µg/mL).</p><p><b>CONCLUSION</b>The phenolic-rich extracts of BF leaves showed antioxidant potentials and inhibited two key carbohydrate-metabolizing enzymes in vitro.</p>

Polyphenols isolated from Acacia mearnsii bark with anti-inflammatory and carbolytic enzyme inhibitory activities / 中国天然药物

The present study was designed to characterize the polyphenols isolated from Acacia mearnsii bark crude extract (B) and fractions (B1-B7) obtained by high-speed counter-current chromatography (HSCCC) and evaluate their anti-inflammatory and carbolytic enzymes (α-glucosidase and α-amylase) inhibitory activities. Fractions B4, B5, B6, B7 (total phenolics 850.3, 983.0, 843.9, and 572.5 mg·g, respectively; proanthocyanidins 75.7, 90.5, 95.0, and 44.8 mg·g, respectively) showed significant activities against reactive oxygen species (ROS), nitric oxide (NO) production, and expression of pro-inflammatory genes interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line RAW 264.7. All the extracts suppressed α-glucosidase and α-amylase activities, two primary enzymes responsible for carbohydrate digestion. A. mearnsii bark samples possessed significantly stronger inhibitory effects against α-glucosidase enzyme (IC of 0.4-1.4 μg·mL) than the pharmaceutical acarbose (IC 141.8 μg·mL). B6 and B7 (IC 17.6 and 11.7 μg·mL, respectively) exhibited α-amylase inhibitory activity as efficacious as acarbose (IC 15.4 μg·mL). Moreover, B extract, at 25 µg·mL, significantly decreased the non-mitochondrial oxidative burst that is often associated with inflammatory response in human monocytic macrophages.

New diterpenoids isolated from Leonurus japonicus and their acetylcholinesterase inhibitory activity / 中国天然药物

Three new labdane diterpenoids, leojaponicone A (1), isoleojaponicone A (2) and methylisoleojaponicone A (3), were isolated from the herb of Leonurus japonicus. The chemical structures of these secondary metabolites were elucidated on the basis of 1D and 2D NMR, including HMQC, and HMBC spectroscopic techniques. All the new compounds were tested in vitro for their acetylcholinesterase and α-glucosidase inhibitory activity. Compounds 1-3 exhibited low inhibitory effects on α-glucosidase with respect to acarbose and exhibited high inhibitory effects on acetylcholinesterase with respect to huperzine A.

Two novel resin glycosides isolated from Ipomoea cairica with α-glucosidase inhibitory activity / 中国天然药物

In the present study, two new compounds from Ipomoea cairica were identified and demonstrated to have α-glucosidase inhibitory activity. They were isolated by column chromatography on silica gel and sephadex LH-20 and finally purified by prep-HPLC, with their structures being elucidated by spectroscopic methods, such as 1D- and 2D-NMR and HR-TOF-MS, and chemical methods. Compounds 1 and 2, named cairicoside A and cairicoside B, were evaluated for α-glucosidase inhibitory activity by the MTT method, with the IC50 values being 25.3 ± 1.6 and 28.5 ± 3.3 μmol·L(-1), respectively.

Synthesis, biological activity and molecular docking research of N-{(4-oxo-thiochroman-3-yl)phenyl-methyl}acetamide derivatives as α-glucosidase inhibitors / 药学学报

In order to develop potent antidiabetic agents that have inhibitory effect to a-glucosidase, twelve β-acetamido ketone derivatives such as N-{[(substituted-4-oxo-thiochroman-3-yl)phenyl]-methyl}acetamide are designed and synthesized through one-pot Dakin-West reaction. Their chemical structures are confirmed by 1H NMR, 13C NMR, IR and HR-MS. In vitro α-glucosidase inhibition assays of compounds 4a-41 were carried out using glucose oxidase method. The result indicated that most of them possess inhibitory activity in vitro. Compound 4k showed the most potent inhibitory activity with 87.3% inhibition of α-glucosidase at the concentration of 5.39 mmol x L(-1). The structure-activity relationship of these β-acetamido ketone derivatives was discussed preliminarily. Moreover, the molecular docking method was used to study the interaction mode of compound 4k and α-glucosidase. Our results will be helpful for designing of α-glucosidase inhibitors in the future.

Euphorbia dioeca Kunth as a novel source for alpha-glucosidase inhibitors / Euphorbia dioeca Kunth como una nueva fuente de inhibidores de alfa-glucosidasa

Euphorbia dioeca Kunth belongs to the Wanderer’s herb complex that is traditionally used for skin diseases and recently as antidiabetic. The methanol and aqueous extracts were evaluated for their in vitro alpha-glucosidase inhibitory activity and an oral starch tolerance test. These extracts showed an IC50 of 0.55 and 0.85 mg/mL, respectively. In diabetic Long Evans rats, the methanol and aqueous extracts reduced significantly the postprandial hyperglycemia peak in 15.2 percent and 12.8 percent, respectively. The alpha-glucosidase inhibitory activity is related with the presence of glycosides, phenolic compounds and flavonoids. Additionally, the safety parameters of both extracts were assessed by means of an acute toxicity test, being classified as innocuous. The traditional use of E. dioeca to control type 2 diabetes was confirmed, being an important source of alfa-glucosidase inhibitors.

Euphorbia dioeca Kunth, pertenece al complejo de plantas medicinales denominado Hierba de la Golondrina; el cual se utiliza para diversos padecimientos, destacando su uso como antidiabético. En dicho marco, se evaluó tanto la actividad inhibitoria de alfa-glucosidasa in vitro, como su desempeño en una prueba de tolerancia a una carga de almidón postprandial. Los extractos inhibieron la actividad de la alfa-glucosidasa con una CI50 de 0.55 y 0.85 mg/mL, respectivamente. Los extractos metanólico y acuoso disminuyeron significativamente el pico hiperglucémico postprandial en un 15.2 por ciento y un 12.8 por ciento, respectivamente, cuando se evaluó en ratas diabéticas. La actividad inhibitoria de alfa-glucosidasa, reflejada en ambas pruebas, está relacionada con la presencia de glicósidos, compuestos fenólicos y flavonoides. De manera adicional, ambos extractos fueron evaluados en una prueba de toxicidad aguda, siendo clasificados como inocuos. Se corroboró el uso tradicional de E. dioeca para el control de la diabetes tipo 2, siendo una importante fuente de compuestos inhibidores de alfa-glucosidasa.