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Yan RY, Lin WH, Lu TL, Chen JL. Conjugated hypercrosslinked polymers imprinted with 3,5-dinitrosalicylic acid for the fluorescent determination of α-amylase activity. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 291:122383. [PMID: 36682253 DOI: 10.1016/j.saa.2023.122383] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 06/17/2023]
Abstract
The discovery of a series of coupling reactions between various building blocks has driven the development of porous organic polymers, but the common usage of expensive and air-sensitive organometallic catalysts and complex procedures in harsh syntheses has limited their expansion. A microporous hypercrosslinked polymer (HCP) was synthesized by polymerizing a naphthalene monomer and a 1,4-dimethoxybenzene crosslinker using Friedel-Crafts alkylation over an FeCl3 catalyst and imprinted with 3,5-dinitrosalicylic acid (DNS). The DNS-molecularly-imprinted HCPs (MIHCPs) were characterized as having IUPAC Type I mesoporosity, a specific surface area of 1134 m2 g-1, a monolayer adsorption capacity of 116 cm2 g-1, pore sizes ranging from 5 to 8.5 Å, amorphous frameworks, and distinctive absorption and emission bands by N2 adsorption/desorption analyses, scanning and transmission electron microscopies, and FTIR, UV-Vis, and fluorescence spectrometries. The π-conjugated imprinted framework endowed the MIHCPs with 405-nm fluorescent emission at a 330-nm excitation and dynamic quenching, which was confirmed by changes in fluorescence lifetime and followed a linear Stern-Volmer plot against 1.0-200 μM DNS template molecules under optimized conditions of a pH 7.0 buffer, an MIHCP concentration of 125 μg mL-1, and a 3.0-min equilibration time. The MIHCPs exhibited a high imprinted factor of 8.7 against nonimprinted HCP and a selectivity of 8.63 against reduced DNS, which enabled fluorometric detection of DNS molecules produced by the hydrolysis of starch with microbial, salivary, and pancreatic α-amylases and the subsequent redox incubation with the DNS oxidant. The fluorometric measurement of α-amylase activity was higher in accuracy and precision (RSD: 2.6-2.8% vs. 3.9-4.0%) than conventional UV-Vis spectrometry because the excellent fluorescent sensitivity and imprinting selectivity of the MIHCP probes enabled the use of higher dilution factors with weaker matrix effects.
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Affiliation(s)
- Ru-Yu Yan
- School of Pharmacy, China Medical University, No. 100 Economic and Trade Road, Taichung City 406040, Taiwan
| | - Wen-Hsin Lin
- School of Pharmacy, China Medical University, No. 100 Economic and Trade Road, Taichung City 406040, Taiwan
| | - Te-Ling Lu
- School of Pharmacy, China Medical University, No. 100 Economic and Trade Road, Taichung City 406040, Taiwan
| | - Jian-Lian Chen
- School of Pharmacy, China Medical University, No. 100 Economic and Trade Road, Taichung City 406040, Taiwan.
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Das S, Das S, Ghangrekar MM. Enzymatic cell disruption followed by application of imposed potential for enhanced lipid extraction from wet algal biomass employing photosynthetic microbial fuel cell. BIORESOURCE TECHNOLOGY 2022; 363:127924. [PMID: 36096325 DOI: 10.1016/j.biortech.2022.127924] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 09/03/2022] [Accepted: 09/05/2022] [Indexed: 06/15/2023]
Abstract
Solvent-free algal cell lysis using fungal enzyme for enhanced lipid recovery diminishes per unit production cost of algal biodiesel. In this investigation, a triple chamber photosynthetic microbial fuel cell (PMFC) was fabricated, where positive potential was imposed in the extraction chamber to draw the negatively charged lipid ions from the cathodic chamber. Under optimum imposed potential of + 3.0 V (vs standard hydrogen electrode) and with 3.5% (v/v) dosage of fungal enzyme in to the algal consortium of cathodic chamber, a maximum of 79.0% of lipid was recovered. Additionally, enzyme-assisted de-oiled algal biomass was applied in the anodic chamber to function as substrate and mediator for exo-electrogens, and the maximum power density of 10.0 W/m3 with 82.4% removal of chemical oxygen demand was achieved while treating synthetic wastewater. Therefore, this cost-effective exploration demonstrated successful bioelectricity production and concomitant wastewater treatment with solvent-free direct lipid recovery from wet algal biomass through PMFC.
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Affiliation(s)
- Swati Das
- PK Sinha Centre for Bioenergy & Renewables, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Sovik Das
- Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - M M Ghangrekar
- PK Sinha Centre for Bioenergy & Renewables, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India; Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
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Lankatillake C, Luo S, Flavel M, Lenon GB, Gill H, Huynh T, Dias DA. Screening natural product extracts for potential enzyme inhibitors: protocols, and the standardisation of the usage of blanks in α-amylase, α-glucosidase and lipase assays. PLANT METHODS 2021; 17:3. [PMID: 33407662 PMCID: PMC7789656 DOI: 10.1186/s13007-020-00702-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/19/2020] [Indexed: 06/01/2023]
Abstract
BACKGROUND Enzyme assays have widespread applications in drug discovery from plants to natural products. The appropriate use of blanks in enzyme assays is important for assay baseline-correction, and the correction of false signals associated with background matrix interferences. However, the blank-correction procedures reported in published literature are highly inconsistent. We investigated the influence of using different types of blanks on the final calculated activity/inhibition results for three enzymes of significance in diabetes and obesity; α-glucosidase, α-amylase, and lipase. This is the first study to examine how different blank-correcting methods affect enzyme assay results. Although assays targeting the above enzymes are common in the literature, there is a scarcity of detailed published protocols. Therefore, we have provided comprehensive, step-by-step protocols for α-glucosidase-, α-amylase- and lipase-inhibition assays that can be performed in 96-well format in a simple, fast, and resource-efficient manner with clear instructions for blank-correction and calculation of results. RESULTS In the three assays analysed here, using only a buffer blank underestimated the enzyme inhibitory potential of the test sample. In the absorbance-based α-glucosidase assay, enzyme inhibition was underestimated when a sample blank was omitted for the coloured plant extracts. Similarly, in the fluorescence-based α-amylase and lipase assays, enzyme inhibition was underestimated when a substrate blank was omitted. For all three assays, method six [Raw Data - (Substrate + Sample Blank)] enabled the correction of interferences due to the buffer, sample, and substrate without double-blanking, and eliminated the need to add substrate to each sample blank. CONCLUSION The choice of blanks and blank-correction methods contribute to the variability of assay results and the likelihood of underestimating the enzyme inhibitory potential of a test sample. This highlights the importance of standardising the use of blanks and the reporting of blank-correction procedures in published studies in order to ensure the accuracy and reproducibility of results, and avoid overlooked opportunities in drug discovery research due to inadvertent underestimation of enzyme inhibitory potential of test samples resulting from unsuitable blank-correction. Based on our assessments, we recommend method six [RD - (Su + SaB)] as a suitable method for blank-correction of raw data in enzyme assays.
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Affiliation(s)
- Chintha Lankatillake
- School of Health and Biomedical Sciences, Discipline of Laboratory Medicine, RMIT University, Bundoora, 3083, Australia
| | - Shiqi Luo
- School of Health and Biomedical Sciences, Discipline of Laboratory Medicine, RMIT University, Bundoora, 3083, Australia
| | - Matthew Flavel
- TPM Bioactives Division, The Product Makers Pty Ltd, Melbourne, Australia
- School of Life Sciences, La Trobe University, Melbourne, Australia
| | - George Binh Lenon
- School of Health and Biomedical Sciences, Discipline of Laboratory Medicine, RMIT University, Bundoora, 3083, Australia
| | - Harsharn Gill
- School of Science, RMIT University, Bundoora, 3083, Australia
| | - Tien Huynh
- School of Science, RMIT University, Bundoora, 3083, Australia
| | - Daniel Anthony Dias
- School of Health and Biomedical Sciences, Discipline of Laboratory Medicine, RMIT University, Bundoora, 3083, Australia.
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Visvanathan R, Qader M, Jayathilake C, Jayawardana BC, Liyanage R, Sivakanesan R. Critical review on conventional spectroscopic α-amylase activity detection methods: merits, demerits, and future prospects. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:2836-2847. [PMID: 32031680 DOI: 10.1002/jsfa.10315] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/31/2020] [Accepted: 02/07/2020] [Indexed: 06/10/2023]
Abstract
α-Amylase is an endoenzyme that catalyses the hydrolysis of internal α-l,4 glycosidic linkages in polysaccharides to produce maltose, maltotriose, and α-limit dextrins. It is widely used in the laboratorial and industrial workflow for several applications. There are several methods utilizing different techniques and substrates to assess α-amylase activity, among which the spectroscopic methods have found widespread applicability due to their ease of use and cost-effectiveness. Depending upon the reaction principle, these assays are classified into four groups: reducing sugar, enzymatic, chromogenic, and amyloclastic methods. Despite the presence of numerous methods, there is no general reliable method to assess α-amylase activity. Each method is shown to have its own merits and demerits. Many improvements have been made to make the available methods more accurate, reliable, and easy. This communication briefly discusses the basic reaction mechanisms and critically reviews the advantages and shortcomings associated with each method. Further recommendations are made for future development. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Rizliya Visvanathan
- National Institute of Fundamental Studies, Kandy, Sri Lanka
- Department of Nutrition, Dietetics & Food, Monash University, Notting Hill, VIC, Australia
| | - Mallique Qader
- National Institute of Fundamental Studies, Kandy, Sri Lanka
- Department of Chemistry, The Open University of Sri Lanka, Nawala, Colombo, Sri Lanka
| | | | | | | | - Ramiah Sivakanesan
- Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Kandy, Sri Lanka
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Chaudhary S, Garg T, Murthy RSR, Rath G, Goyal AK. Recent approaches of lipid-based delivery system for lymphatic targeting via oral route. J Drug Target 2014; 22:871-82. [PMID: 25148607 DOI: 10.3109/1061186x.2014.950664] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lymphatic system is a key target in research field due to its distinctive makeup and huge contributing functions within the body. Intestinal lymphatic drug transport (chylomicron pathway) is intensely described in research field till date because it is considered to be the best for improving oral drug delivery by avoiding first pass metabolism. The lymphatic imaging techniques and potential therapeutic candidates are engaged for evaluating disease states and overcoming these conditions. The novel drug delivery systems such as self-microemulsifying drug delivery system, nanoparticles, liposomes, nano-lipid carriers, solid lipid carriers are employed for delivering drugs through lymphatic system via various routes such as subcutaneous route, intraperitoneal route, pulmonary route, gastric sub-mucosal injection, intrapleural and intradermal. Among these colloidal particles, lipid-based delivery system is considered to be the best for lymphatic delivery. From the last few decades, mesenteric lymph duct cannulation and thoracic lymph duct cannulation are followed to assess lymphatic uptake of drugs. Due to their limitations, chylomicrons inhibitors and in-vitro models are employed, i.e. lipolysis model and permeability model. Currently, research on this topic still continues and drainage system used to deliver the drugs against lymphatic disease as well as targeting other organs by modulating the chylomicron pathway.
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Affiliation(s)
- Shilpa Chaudhary
- Department of Pharmaceutics, ISF College of Pharmacy , Moga, Punjab , India
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