Glucosidase Inhibitory Activity Research Articles

Screening of anti-diabetic potential of the siddha formulation sambirani poo kuligai by in-vitro alpha glucosidase enzyme inhibition assay

Background: Noninsulin-dependent diabetes mellitus (NIDDM) is a common disease of the endocrine system caused by the decreased secretion of insulin by the pancreatic Langerhans beta cell or by the lowering of insulin resistance due to excessive absorption of glucose. The Siddha system of medicine is a traditional medical system that uses a scientific and holistic approach to provide preventive, promotive, curative, rejuvenative and rehabilitative health care. According to Siddha literature, diabetes is known as Innippu Neer, Madhumegam and Neerizhivu. The various reasons for the cause of this disease are attributed to foodhabits and lifestyle changes and also due to hereditary causes. One of the therapeutic approaches is to decrease the postprandial hyperglycemia by retarding the absorption of glucose through the inhibition of carbohydrate-hydrolyzing enzymes, such as a-amylase and ?-glucosidase. ?-Glucosidase are enzyme that catalyze the absorption of digested glucose from dietary polysaccharides in the small intestine. Aim: The aim of the present study is to evaluate the anti-diabetic potential of the siddha formulation of Sambirani Poo Kuligai(SPK) by alpha glucosidase enzyme inhibition assay. Method: The spectrophotometric assay method was used to find alpha glucosidase inhibitory activity. Results: SPK showed presence of alpha glucosidase inhibitory potential with the maximum inhibition of about 41.74 ± 3.578 % and the corresponding IC50 is 606.5 ± 49.51?g/ml. Conclusion: This in-vitro study revealed the presence of the alpha glucosidase activity in the siddha formulation Sambirani Poo Kuligai possesses antidiabetic activity

Anti-diabetic Potentials of Cookies from Wheat, Sweet Potato and African Yam Beans (Sphenostylis stenocarpa) Composite Flour Blends

The consumption of cookies offered reliable advantages to the consumers, which included but not limited to perfect eating ability, prolong shelf live and acceptability among all nations. This study thus, investigated the antioxidant and anti-diabetic properties of cookies obtained from wheat-African yam bean-sweet potato composite flour blends at different ratios. The African yam bean and sweet potato were thoroughly processed, milled, sieved thereafter mixed with the commercial wheat flour. Four blends were prepared by using the trial mixing ratio and 100% wheat flour and later used to bake cookies. The proximate, amino acid compositions, antioxidant, amylase and glucosidase inhibitory activities as well as physical properties of the composite cookies were examined while panelists were assigned to assess the cookie samples. The results of the proximate composition showed that the composite flour technology had significant (p<0.05) positive effects on the cookies. Meanwhile, the amino acid compositions of the cookies revealed that the cookie samples were of high aromatic and hydrophobic amino acids, respectively with optimum physical properties. No panelist showed a total dislike for the taste of any of the samples. The added soybean seeds flours showed no significant (p<0.05) effect on the acceptability and preference of the samples. Hence, it is possible to produce better protein and high nutritional cookies from these flour blends. We therefore concluded that the cookies rich in antioxidants and anti-diabetic potentials could be produced from wheat-African yam bean-sweet potato composite flour.

Biginelli dihydropyrimidines carrying azole rings: Synthesis, computational studies, and evaluation of alpha‐glucosidase inhibitory and antimicrobial activities

In the current study, we designed three novel compounds by merging two valuable nitrogen-containing pharmacophores, namely dihydropyrimidine (DHPM) and azole, within a single molecule. To obtain the target molecules, azole-linked benzaldehydes were initially synthesized via nucleophilic aromatic substitution reaction between 4-fluorobenzaldehyde and pyrazole, imidazole, or 1,2,4-triazole. Afterward, Biginelli reaction was applied to yield azole-carrying DHPMs. Following structural confirmation, the obtained compounds were tested for their alpha (α)-glucosidase inhibitory and antimicrobial activities. According to the biological data, DHPM-P and DHPM-T showed strong inhibition values whereas DHPM-I failed to effectively inhibit the α-glucosidase enzyme. This situation was explained by molecular docking studies of all compounds into the binding site of alpha-glucosidase. The title compounds also presented moderate antibacterial and antifungal activities. Computational methods based on density functional tight binding (DFTB) and density functional theory (DFT) calculations, along with molecular dynamics (MD) simulations were used to analyze the reactive properties of the compounds. A combination of DFTB and DFT calculations was applied to obtain the lowest energy conformations of the molecules. Further computational analysis included calculations of local reactivity descriptors, such as molecular electrostatic potential and average local ionization energy, by applying DFT calculations. DFT calculations were also used to study intramolecular non-covalent interactions. MD simulations were employed to understand how the title molecules behave in water and to obtain their solubility parameters.

Flavonoids from Alpinia vietnamica, and their cytotoxic, antioxidative, and α‐glucosidase inhibitory activities

AbstractPhytochemical research of the 80% EtOH whole plant extract of Alpinia vietnamica H.Ð. Tran, Luu & Skornick resulted in the isolation and structural elucidation of seven compounds 1–7, including two flavones quercetin‐3‐O‐α‐l‐rhamnosyl (1→2)‐α‐l‐rhamnoside (1) and diosmetin (2), three flavanones pinocembrin (3), alpinetin (4) and 5‐O‐methylnaringenin (5), and two chalcones cardamonin (6) and helichrysetin (7). The isolated compounds have shown biological effects at different levels. Two chalcones 6–7 showed cytotoxicity toward four cancer cell lines KB, MCF7, A549, and HepG2, especially compound 7 strongly inhibited the growth of A549 cancerous cells with the IC50 of 6.81 µm. Flavone 1 strongly exhibited antioxidative activity to scavenge DPPH radicals with the IC50 of 51.68 µm. Flavone 2 and flavanone 4 moderately inhibited enzyme α‐glucosidase with the IC50 values of 296.34–324.64 µm.

In Vitro Evaluation of Alpha Amylase and Alpha Glucosidase Inhibitory Activity of Kamadhenu Ark extracts of Climate Smart Crop Millets

Diabetes Mellitus is characterized by abnormal Metabolism of glucose. The maintenance of glucose levels in blood without any side effects is still challenging in the medication of this disease. Various medical approaches like Allopathy, Homeopathy, Ayurveda, Unani etc are striving a lot for success in this field of medication. Present study is aimed to evaluate the Antidiabetic activity of Millets in combination with Kamadhenu Ark as solvent for the probable alpha Amylase and alpha Glucosidase inhibitory activities to reduce hyperglycemia. The Millets namely Paspalum scrobiculatum, Panicum miliaceum, Panicum sumatrense were selected for the study. The Kamadhenu Ark Extracts were prepared by Maceration method. The extracts were used for the estimation of alpha amylase and alpha-glucosidase inhibition activity. Extract of Panicum miliaceum exhibited highest α amylase and α glucosidase inhibitory potential with IC50 values of 0.239 and 1.526 mg/ml, respectively, which was comparable with acarbose (0.258 and 1.985 mg/ml). Extracts of Paspalum scrobiculatum and Panicum sumatrense have shown low activity. Present study paves a new path revealing the effective inhibition of α amylase and α glucosidase by Kamadhenu Ark extract of Panicum miliaceum (Proso Millet KPM).

Pharmacological and biotechnological overview of Sauropus androgynus L. Merr.: an underexploited perennial shrub

Sauropus androgynus L. Merr is an unexploited medicinal shrub under the family Phyllanthaceae known as a green multivitamin plant and used as a leafy vegetable. Many phytochemicals from the leaf extracts of S. androgynous act as antioxidant, anti-microbial, wound-healing, anti-inflammatory, anti-diabetic, and anti-obesity agents and can potentially enhance breast milk production. The leaf extracts of this shrub contain ascorbic acid, eugenol, gallic acid, caffeic acid, syringic acid, p-coumaric acid, sinapic acid, ferulic acid, and different types of flavonoids. These phytochemicals have oxidative scavenging, glucosidase inhibitory, and superoxide dismutase activities. The plant has several nutrients to help metabolic activity and increase longevity. Herbal industries depend on natural resources. Identifying plant species is also essential before using them as herbal ingredients. DNA barcoding tags are used to determine the authenticity of plant species and herbal drugs. Seven barcoding markers have been tested for the identification of S. androgynus. Markers rbcl, rpoC1, and trnH-psbA showed the fragment size at 580, 500, and 520 bp, respectively. However, rpoC1I and adh reflect at 380 and 300 bp and the ycf5 show at 450 bp. These markers may be used to authenticate the plant and prepare herbal medicine. This review highlighted the basic biology, phytochemical, pharmacological, and biotechnological overview of S. androgynus for sustainable human health.

Phytoconstituents of Terminalia catappa linn fruits extract exhibit promising antidiabetic activities against α-amylase and α-glucosidase in vitro and in silico

Terminalia Catappa fruits are recognized for their use in diabetes treatment, yet the mechanism by which they inhibit diabetes-related enzymes remain largely undefined. This study aimed to elucidate the therapeutic potential and interactions of T. catappa fruit extract through in vitro and in silico approaches. The compounds from T. catappa fruit were extracted using microwave-assisted extraction techniques, followed by qualitative phytochemical screening and quantitative analysis via GC-MS. The physicochemical properties were evaluated according to the Lipinski rule and ADMET criteria. Antidiabetic analyses, both in vitro and in silico, were performed on the secondary metabolites found in T. catappa fruit, targeting α-amylase and α-glucosidase enzymes. The methanol and ethyl acetate extracts of T. catappa fruit contained alkaloids, flavonoids, saponins, steroids, and terpenoids. These extracts inhibited α-glucosidase and α-amylase in a dose-dependent manner, with the methanol extract of T. catappa showing significantly higher inhibitory activity than pure acarbose (by two- and five-fold, respectively) and the ethyl acetate extract. Furthermore, the antioxidant activity of the methanolic extract was seven times greater than that of the ethyl acetate extract. Molecular docking studies supported these findings, revealing that the ΔG values of gibberellic acid, rescinnamine, and digoxin were comparable to those of acarbose. Notably, digoxin has higher ΔG values against α-amylase than acarbose, while gibberellic acid, rescinnamine, and nerolidol showed ΔG values similar to acarbose. Gibberellic acid, unique to the methanol extract, demonstrated high ΔG values, suggesting its significant role in the extract's enhanced glucosidase and amylase inhibitory activities. This study identifies specific compounds (digitoxin, rescinnamine, gibberellic acid, and nerolidol) and proposes the potential of multi-target drugs in diabetes treatment. Understanding these phytochemical constituents and their effects on diabetes-involved enzymes could benefit individuals with type 2 diabetes, particularly those at higher risk of complications.

In vitro and in silico studies of alpha glucosidase inhibition and antifungal activity of coffea canephora husk.

The coffea canephora husk, a protected agricultural crop, is abundant in Vietnam. Examining the effects of C. canephora husk compounds on α-glucosidase and antifungal drug activity was the primary objective of this research. A cholestane-type steroid, coffeacanol A (1), was extracted from the ethyl acetate extract. Three cholestane-type derivatives (2-4) and three additional known compounds (5-7) were separated, and we used a variety of chromatographic techniques to identify a total of six substances. We used NMR to determine the chemical structures of these substances. Extensive HR-MS-ESI analysis and NMR experimental data were used to confirm the structure of the novel metabolite (1). The cholestane-type steroid was initially discovered in the Coffea canephora husk, marking the first instance in the coffee plant family to reveal chemical structures (1-7). The inhibition of α-glucosidase was found to be significantly higher in all compounds tested, with the exception of compounds (2) and (5). In vitro, the positive control showed the lowest inhibition, and the range of IC50 values was calculated to be 27.4 to 96.5 μM, which is lower than the IC50 value of 214.50 μM for the acarbose control. With an IC50 value of 27.4 μM, compound (7) showed the greatest capacity to inhibit α-glucosidase among the test compounds. The 3TOP and 2VF5 enzyme crystal structures were used for in silico docking investigations and validations of compounds (1-7). In silico calculations to explain how compound (7) shows high activity in vitro via the enzyme inhibition mechanism by residual amino acids, like Gly 1102 (B chain) and Glu 1095 (B chain), and their relative interaction with compounds (7) and acarbose. Compound (7) exhibited the best antifungal activity against Candida albicans fungus among three fungi, namely Candida albicans, Trichophyton mentagrophytes, and Trichophyton rubrum, with a MIC value of 25 μM. Compound (7) and fluconazole combined to form similar interactions in the contact ligand model, including the functional group, capping group, and linker part, which interacted fully with the 2VF5 enzyme, leading to effective in vitro inhibition.

Antioxidant, Antibacterial, α-Amylase, and α-Glucosidase Inhibition, and Anti-inflammatory Activities of Mimosa Rubicaulis Lam.

Background: The use of medicinal plants as supplemental or alternative medicine is widespread around the world. For the development of new drugs, studies on these medicinal plants that include pharmacological and toxicological assessments are crucial. Objective: This work aimed to find the total phenolic and flavonoid content, antioxidant, antibacterial, and antidiabetic potential of the traditionally used medicinal plant Mimosa rubicaulis Lam. Methods: The in vitro antidiabetic potential of methanolic extract and its fractions of the roots of M. rubicaulis were performed via enzyme (α-glucosidase and α-amylase) inhibition assays. Antioxidant and anti-inflammatory activities were carried out using 2,2 Diphenyl-1-picrylhydrazyl (DPPH), and reactive oxygen species (ROS) inhibiting methods. Well diffusion method is applied for antibacterial activity. Results: The crude extract reported the highest inhibition activity against α-glucosidase with an IC50 value of 10.29 ± 0.35 μg/mL compared to the standard acarbose’s IC50 value of 5.653 ± 0.29 μg/mL. Similarly, the ethyl acetate (EA) fraction disclosed significant inhibition against α-amylase with an IC50 value of 108.7 ± 0.66 μg/mL compared to the standard acarbose’s IC50 value of 6.01 ± 0.14 μg/mL. Likewise, the EA fraction showed the maximum antioxidant activity with an IC50 value of 11.89 ± 1.05 μg/mL among the crude extract and its fractions. Conclusion: Mimosa rubicaulis was found to have α-glucosidase and α-amylase inhibition, antiinflammatory, and antibacterial activity. To the best of our knowledge, this is the first report of α- glucosidase and α-amylase inhibition activity of this plant. Further studies on this plant are required to isolate potent compounds.

First report of piperidone extracts as tyrosinase and α-glucosidase inhibitors from fruits of Piper retrofractum

Importance of the work: Piper retrofractum is used as a spice. This report is the first to identify tyrosinase and α-glucosidase inhibitors extracted from this plant. Objectives: To separate and identify the bioactive compounds from the fruits of P. retrofractum and to evaluate their tyrosinase and α-glucosidase inhibition activities. Materials & Methods: The EtOAc extract was isolated and purified using various chromatographic techniques. The structures of isolated compounds were confirmed based on their spectroscopic data. The tyrosinase and α–glucosidase inhibition activities of the isolated compounds were assessed based on a colorimetric method, using kojic acid and acarbose, respectively, as positive controls. Results: Seven known compounds were identified, named methyl piperate (1), guineensine (2), piperine (3), N-feruloyltyramine (4), (3S, 4S)-4-chloro-3-hydroxy-2-piperidin-2-one (5), 3-chloro-4-hydroxy-2-piperidone (6) and 3α,4α-epoxy-2-piperidone (7). Piperidones 5 and 6 showed tyrosinase inhibition with concentration at 50% inhibition (IC50) values of 4.91 mM and 11.0 mM, respectively, whereas the alkylamides 1–3 and phenylpropanamide 4 were not active. On the other hand, only phenylpropanamide 4 was active against maltase and sucrase with IC50 values of 0.28 mM and 0.5 mM, respectively. Piperidone 5 showed weak inhibition against both maltase and sucrase α-glucosidases, while the piperidones 6 and 7 exhibited weak inhibition against sucrase α-glucosidases. Main finding: The piperidones were more active against tyrosinase than piperine, which is representative metabolite from this plant. Further study on the inhibitory mechanism may lead to suitable applications of the extract in cosmetics.

Antidiabetic phytodrug from Maerua angolensis DC: Formulation, standardization, in vitro and in vivo evaluations

Maerua angolensis is a shrub or small tree widely distributed in tropical Africa. The plant materials are used for various ethnomedicinal applications across the region, including the prevention and treatment of diabetes. This study was aimed to evaluate the antidiabetic potential of formulated freeze-dried aqueous extract of Maerua angolensis leaves using standard in vitro and in vivo experimental models. Infusion extract of the plant's powdered dried leaves was prepared, the resultant extract was freeze-dried and formulated (denoted FIEMa). The physicochemical, quantitative and qualitative phytochemical constituents of FIEMa were determined using analytical techniques (UV-visible and HPLC). The antidiabetic activity of the reconstituted formulation was investigated using in vitro and in vivo models. The in vitro activity was assessed using Phosphomolybdenum assay and DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity for antioxidant effect, and α-amylase inhibition and α- glycosidase inhibition assays. The assays of the normoglycemic, oral glucose load tolerance, and single-dose alloxan (150 mg/kg) induced diabetes in rats were used for in vivo antidiabetic activity. The results show that FIEMa contains valuable phytochemicals. It exhibited antioxidant effect, α-amylase and α- glucosidase inhibition activities. FIEMa did not significantly reduce blood glucose levels (BGL) in normoglycemic mice but produced a significant reduction of BGL in the oral glucose tolerance test. In alloxan-induced diabetic rats, significant reductions of BGL were observed in groups treated with high doses of FIEMa in the single-dose study and from the second week onwards in the repeated dose study. It also exhibited less reduction in body weight compared to the control group. The findings indicate that FIEMa has an antidiabetic activity, low risk of hypoglycemia, and body weight loss. The valuable phytochemicals plausibly mediate this effect, especially the dominant betulinic acid detected in FIEMa, most likely acting in synergy.

Exploring for HPLC-MS/MS Profiles and Biological Activities of Different Extracts from Allium lycaonicum Siehe ex Hayek from Turkey Flora.

The present study was designed to determine the phenolic constituents, antioxidant, and enzyme inhibition activities of aerial parts and bulbs of Allium lycaonicum (family Amaryllidaceae). Extracts were prepared by maceration and Soxhlet/infusion using hexane, methanol, and water as extraction solvents. Generally, extracts from the aerial parts showed higher total phenolic and individual components and antioxidant activity than their respective bulb extracts. Maceration with water was the best to extract total phenolic content from the aerial parts (29.00 mg gallic acid equivalents (GAE)/g), while the Soxhlet extraction with hexane (22.29 mg GAE/g) was the best for the bulb. Maceration with methanol recovered the highest total flavonoid content from both the aerial parts (41.95 mg (rutin equivalents (RE)/g) and bulb (1.83 mg RE/g). Polar extracts of aerial parts were characterized by higher abundance of kaempferol-3-glucoside (≤20,624.27 µg/mg), hyperoside (≤19,722.76 µg/g), isoquercitrin (≤17,270.70 µg/g), delphindin-3,5-diglucoside (≤14,625.21 µg/g), and rutin (≤10,901.61 µg/g) than the bulb. Aerial parts' aqueous extract, prepared by maceration, exerted the highest anti-ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical activity (64.09 mg trolox equivalents (TE)/g), Cu++ (83.03 mg TE/g) and Fe+++ (63.03 mg TE/g) reducing capacity while that prepared by infusion recorded the highest anti-DPPH (2,2-diphenyl-1-picrylhydrazyl) radical (31.70 mg TE/g) and metal chelating (27.66 mg EDTAE/g) activities. The highest total antioxidant activity (1.46 mmol TE/g) was obtained by maceration of the bulb with water. Extracts obtained by organic solvents showed remarkable enzyme inhibition properties against the tested enzymes. Soxhlet extraction of the bulb with hexane and methanol recorded the highest acetylcholinesterase inhibition (4.75 mg galanthamine equivalents (GALAE)/g) and tyrosinase inhibition (139.95 mg kojic acid equivalents/g) activities, respectively. Extracts obtained by maceration of the bulb with methanol and the aerial parts with hexane exerted the highest glucosidase inhibition (3.25 mmol acarbose equivalents/g) and butyrylcholinesterase inhibition (20.99 mg GALAE/g) activities, respectively. These data indicated that A. lycaonicum is a source of bioactive molecules with potential antioxidant and enzyme inhibition properties. Nonetheless, the extracts obtained through various solvents and extraction techniques showed variations in their phytoconstituent composition and biological properties.

Research progresses on the effect of drying technology on α-glucosidase inhibitors in plants

Diabetes is a metabolic disease characterized by hyperglycemia. It is one of the chronic non-communicable diseases after tumor and cardiovascular diseases, which seriously threatens the life and health safety of human beings. Alpha-glucosidase inhibitors can reduce fasting blood glucose and postprandial blood glucose. Compared with traditional inhibitors, the hypoglycemic components extracted from plants have less side effects, have an integrated mechanism of action, and the advantage of mild and lasting effects. Drying technology plays the role of controlling insects, mildew and not easy to deteriorate, which is conducive to the storage, transportation and dispensing of plants, so drying has become the essential operation unit of plants processing. Recently, various drying methods have been applied to the processing of hypoglycemic plants. The choice of drying technology affects the content and activity of active substances in plants, as well as the energy consumption, equipment investment, and drying cost. Therefore, this article reviews the effects of commonly used drying methods on substances with glucosidase inhibitory activity in hypoglycemic plants.

Comparative Study on the Chemical Profile, Antioxidant Activity, and Enzyme Inhibition Capacity of Red and White Hibiscus sabdariffa Variety Calyces.

Hibiscus sabdariffa L. (Family: Malvaceae) is believed to be domesticated by the people of western Sudan sometime before 4000 BC for their nutritional and medicinal properties. This study aimed to investigate the chemical profile, antioxidant activity, and enzyme inhibition property of extracts from red roselle (RR) and white roselle (WR) varieties grown in Sudan. Three aqueous extracts obtained by maceration, infusion, and decoction, in addition to the methanolic one, were prepared from the two roselle varieties. Results showed that the highest total phenolic and flavonoid contents of RR were obtained from the extracts prepared by infusion (28.40 mg GAE/g) and decoction (7.94 mg RE/g) respectively, while those from the WR were recorded from the methanolic extract (49.59 mg GAE/g and 5.81 mg RE/g respectively). Extracts of RR were mainly characterized by high accumulation of chlorogenic acid (6502.34-9634.96 mg kg-1), neochlorogenic acid (937.57-8949.61 mg kg-1), and gallic acid (190-4573.55 mg kg-1). On the other hand, neochlorogenic acid (1777.05-6946.39 mg kg-1) and rutin (439.29-2806.01 mg kg-1) were the dominant compounds in WR. All extracts from RR had significant (p < 0.05) higher antioxidant activity than their respective WR except in their metal chelating power, where the methanolic extract of the latter showed the highest activity (3.87 mg EDTAE/g). RR extracts prepared by infusion recorded the highest antioxidant values (35.09, 52.17, 65.62, and 44.92 mg TE/g) in the DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), CUPRAC (cupric ion reducing antioxidant capacity), and FRAP (ferric reducing antioxidant power) assays, respectively. All aqueous extracts from the WR exerted significant (p < 0.05) acetylcholinesterase (AChE) inhibitory activity (3.42-4.77 mg GALAE/g; GALAE = galantamine equivalents), while only one extract, obtained by maceration, from RR exerted AChE inhibitory activity (4.79 mg GALAE/g). All extracts of the RR showed relatively higher BChE (butyrylcholinesterase) inhibitory activity (3.71-4.23 mg GALAE/g) than the WR ones. Methanolic extracts of the two roselle varieties displayed the highest Tyr (tyrosinase) inhibitory activity (RR = 48.25 mg KAE/g; WR = 42.71 mg KAE/g). The methanolic extract of RR exhibited the highest amylase (0.59 mmol ACAE/g) and glucosidase (1.46 mmol ACAE/g) inhibitory activity. Molecular docking analysis showed that delphinidin 3,5-diglucoside, rutin, isoquercitrin, hyperoside, and chlorogenic acid exerted the most promising enzyme inhibitory effect. In conclusion, these findings indicated that the chemical profiles and biological activity of roselle varied according to the variety, extraction solvent, and technique used. These two roselle varieties can serve as a valuable source for the development of multiple formulations in food, pharmaceutical, and cosmetic industries.

An alternative route for tricyclic quinazolinone-iminosugars and their glucosidase inhibitory activities

A series of novel tricyclic quinazolinone-iminosugars 5 and their derivatives 7 were obtained from the tosylated sugars by three steps. Firstly, the reaction of the isopropylidene protected sugar tosylate 1 and o-aminobenzylamine 2 generated the precursor tricyclic quinazolin-iminosuar 3, which was then oxidized by KMnO4 to produce the corresponding quinazolinone 4. Finally, removal of the isopropylidene group yielded the target tricyclic quinazolinone iminosugars 5. In addition, quinazolinone-iminosugars 4ac, 4bc and 4cc who contain bromine in the aromatic region underwent Suzuki reaction with phenylboronic acid, followed with the removal of the isopropylidene group to afford the derivatives 7. This strategy will help to construct such fused multicyclic quinazolinone-iminosugars efficiently. Some compounds show certain inhibition against α-glucosidase (saccharomyce cerevisiae).

Comparative Studies of Essential Oil Composition and Biological Activities of Callistemon citrinus from Western Himalaya.

This work described a comprehensive study to estimate chemical constituents of essential oils (EOs) extracted from different parts of the Callistemon citrinus viz: fruits, leaves and aerial part. The EOs were characterized using physicochemical parameters, and GC-FID/MS. It was observed that among different parts, aerial part has the highest oil yield (0.90 %) followed by leaves and fruits. Further, seventeen compounds were characterized, and represented total amount (97.2-99.5 %) with domination of monoterpenes (12.5-34.6 %) and oxygenated monoterpenes hydrocarbon (61.8-86.8 %). α-pinene (11.8-24.7 %), α-phellandrene (1.2-3.0 %), p-cymene (3.3-3.9 %) and 1,8-cineole (58.3-85.1 %) were found as major compounds in C. citrinus samples. These major compounds are the quality chemical markers of C. citrinus oil. The findings revealed significant quantitative variations in EO composition of samples and were also clearly supported by multivariate statistical analysis. Moreover, EOs were evaluated for glucosidase and colon cancer cell lines inhibitory activities, which were found promising.

LC-MS and NMR Based Plant Metabolomics: A Comprehensive Phytochemical Investigation of Symphytum anatolicum.

The application of metabolomics to the study of plants is growing because of the current development of analytical techniques. The most commonly used analytical technology driving plant metabolomics studies is Mass Spectrometry (MS) coupled to liquid chromatography (LC). In recent years, Nuclear Magnetic Resonance (NMR) spectroscopy, not requiring a previous chromatographic separation, has been receiving growing attention for metabolite fingerprinting of natural extracts. Herein, an integrated LC-MS and 1H NMR metabolomic approach provided a comprehensive phytochemical characterization of Symphytum anatolicum whole plant, taking into account both primary and specialized metabolites. Moreover, the NMR analyses provided direct quantitative information. Species belonging to the Symphytum genus, known as comfrey, have shown several biological activities including anti-inflammatory, analgesic, hepatoprotective, antifungal, and antibacterial. The LC-MS profile showed the presence of 21 main specialized metabolites, belonging to the classes of flavonoids, phenylpropanoids, salvianols, and oxylipins. The 1H NMR spectrum revealed the occurrence of metabolites including organic acids, phenolics, flavonoids, sugars, and amino acids. A quantitative analysis of these metabolites was performed and their concentration was obtained with respect to the known concentration of TSP, by means of the software package Chenomx which allows quantification of individual components in the NMR spectra. Furthermore, the phenolic content, antioxidant activity, glucosidase, and tyrosinase inhibitory activity of S. anatolicum extract were evaluated. The resulting bioactivity profile suggests how S. anatolicum represents a source of metabolites with health-promoting activity.

Study on chemical composition and α‐glucosidase inhibitory activity from the leaves of Muntingia calabura

Abstract“Trứng cá” (Muntingia calabura) is a special species of the genus Muntingia. Phytochemical studies on the leaves of M. calabura showed that seven compounds were isolated, including R‐(+)‐5‐(δ‐tocopherol‐5'‐yl)‐δ‐tocopherol (1), trans‐phytol (2), ergosta‐4,6,8(14),22‐tetraen‐3‐one (3), ergosterol peroxide (4), stigmasta‐4‐ene‐3,6‐dione (5), 6β‐hydroxystigmast‐4‐en‐3‐one (6), and β‐sitosterol (7). The structures of the compounds were elucidated by mass spectrometry, nuclear magnetic resonance spectroscopy (NMR), and compared to the literature. The biological test result for all isolated compounds showed that compounds 1‐3, and 5‐7 have the ability to inhibit moderately α‐glucosidase with IC50 values ranging from 57.9 to 249.5 μM. Compound 3 processed a significant inhibitory activity effect with an IC50 value of 57.9 μM, more potent than the positive control, acarbose (IC50, 214.5 μM). This is the first time compounds 1‐5 have been reported for the Muntingia genus.

Study on α‐glucosidase inhibitory activity of isolated flavones from genus Artocarpus and their enzyme kinetics

AbstractFlavonoids are the major compounds associated with diverse bioactivities, especially with α‐glucosidase inhibitory activity related to diabetes mellitus. The study reported the α‐glucosidase inhibitory activity of seventeen flavonoids isolated from Artocarpus heterophyllus, Artocarpus rigida, and Artocarpus altilis. The results indicated that all flavones possessed an α‐glucosidase inhibitory effect, in which compounds 3, 5‐7, 9‐17 strongly inhibited α‐glucosidase enzyme with the IC50 value range from 1.5 to 6.4 μM. Based on their structure‐activity relationships, the prenylation patterns at the flavonoid skeleton gave significantly potent inhibitory abilities against α‐glucosidase. Further kinetics studies were conducted to determine the inhibition type of these prenylated flavones. This is the first time prenylflavones isolated from genus Artocarpus were reported on the α‐glucosidase inhibitory activity and its kinetics. The report suggested that prenylflavones are potential sources for diabetes mellitus treatment.

Study of Optimal Conditions to Grow Thai Ganoderma, Fruiting Test, Proximate and Their Alpha Glucosidase Inhibitory Activity.

Ganoderma (Ganodermataceae) has a worldwide distribution and has been widely used in traditional medicines. In this study, we report wild strains of Ganoderma that include two G. sichuanense and one G. orbiforme from northern Thailand. Optimal conditions for mycelium growth were ensured. The most favourable medium was potato sucrose agar for G. sichuanense and oatmeal agar for G. orbiforme and at 25 °C and 30 °C and pH 4-8. All types of cereal grains can be used to promote the growth of the mycelia of Ganoderma species. Fruiting tests were performed. All strains of Ganoderma produce fruiting bodies successfully in bag culture at 28 ± 1 °C with 75-85% relative humidity. Only G. orbiforme produced fruiting bodies in field cultivation at the laboratory scale. In the first flush yields, the G. sichuanense strain MFLUCC 22-0064 gave better production (the B.E was 152.35 ± 6.98 g). This study is the first to document the bag and field cultivation of wild Thai G. orbiforme. Ganoderma species are revealed to contain high amounts of fiber (47.90-52.45% d.b.), protein (12.80-14.67% d.b.), fat (4.90-5.70% d.b.), and carbohydrates (3.16-4.02% d.b.). Additionally, G. sichuanense and G. orbiforme were preliminarily screened for biological activity for inhibition of alpha-glucosidase enzyme activity. The IC50 values of G. orbiforme (MFLUCC 22-0066) was 105.97 ± 1.36 µg/mL and G. sichuanense (MFLUCC 22-0064) was 126.94 ± 0.87 µg/mL. Both strains had better inhibition than acarbose (168.18 ± 0.89 µM). These results on wild strains of Ganoderma will be useful for further studies on the applications of Ganoderma. Later the species can be introduced to domestic markets for cultivation and medicinal use.