{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T04:57:02Z","timestamp":1776920222230,"version":"3.51.2"},"reference-count":38,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,2]],"date-time":"2021-01-02T00:00:00Z","timestamp":1609545600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002924","name":"FEDER","doi-asserted-by":"publisher","award":["POCI\/01\/0145\/FEDER\/007265"],"award-info":[{"award-number":["POCI\/01\/0145\/FEDER\/007265"]}],"id":[{"id":"10.13039\/501100002924","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002924","name":"FEDER","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-030163"],"award-info":[{"award-number":["POCI-01-0145-FEDER-030163"]}],"id":[{"id":"10.13039\/501100002924","id-type":"DOI","asserted-by":"publisher"}]},{"name":"FCT\/MEC","award":["UID\/ QUI\/50006\/2013"],"award-info":[{"award-number":["UID\/ QUI\/50006\/2013"]}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["SFRH\/BD\/138835\/2018"],"award-info":[{"award-number":["SFRH\/BD\/138835\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Human neutrophil elastase (HNE) is used as diagnostic biomarker for inflammation\/infection. In this work, 10 ionic liquids (ILs) and 11 ionic liquids active pharmaceutical ingredients (ILs-APIs) were tested to evaluate the inhibition effect on the activity of porcine pancreatic elastase enzyme, frequently employed as a model for HNE. The insertion of ionic liquids in some drugs is useful, as the insertion of ILs with inhibitory capacity will also slow down all processes in which this enzyme is involved. Therefore, a spectrophotometric method was performed to the determination of EC50 values of the compounds tested. EC50 values of 124 \u00b1 4 mM to 289 \u00b1 11 mM were obtained, with the most toxic IL for elastase being tetrabutylammonium acetate and the least toxic 1-butyl-3-methylimidazolium acetate. Moreover, sodium salicylate (raw material) presented the lower and benzethonium bistriflimide the higher EC50 when compared with all the IL-APIs tested. This work provides significant information about the effect of the studied IL and IL-APIs in elastase enzyme activity.<\/jats:p>","DOI":"10.3390\/molecules26010200","type":"journal-article","created":{"date-parts":[[2021,1,3]],"date-time":"2021-01-03T19:54:46Z","timestamp":1609703686000},"page":"200","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Evaluation of Ionic Liquids and Ionic Liquids Active Pharmaceutical Ingredients Inhibition in Elastase Enzyme Activity"],"prefix":"10.3390","volume":"26","author":[{"given":"F\u00e1tima A. R.","family":"Mota","sequence":"first","affiliation":[{"name":"LAQV, REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Unidade de Investiga\u00e7\u00e3o para o Desenvolvimento do Interior, Instituto Polit\u00e9cnico da Guarda, Av. Dr. Francisco de S\u00e1 Carneiro, No. 50, 6300-559 Guarda, Portugal"}]},{"given":"Sarah A. P.","family":"Pereira","sequence":"additional","affiliation":[{"name":"LAQV, REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3510-948X","authenticated-orcid":false,"given":"Andr\u00e9 R. T. S.","family":"Araujo","sequence":"additional","affiliation":[{"name":"LAQV, REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Unidade de Investiga\u00e7\u00e3o para o Desenvolvimento do Interior, Instituto Polit\u00e9cnico da Guarda, Av. Dr. Francisco de S\u00e1 Carneiro, No. 50, 6300-559 Guarda, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6539-1741","authenticated-orcid":false,"given":"M. L\u00facia M. F. S.","family":"Saraiva","sequence":"additional","affiliation":[{"name":"LAQV, REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"508","DOI":"10.1111\/j.1600-0625.2011.01256.x","article-title":"Sensor materials for the detection of human neutrophil elastase and cathepsin G activity in wound fluid","volume":"20","author":"Hasmann","year":"2011","journal-title":"Exp. Dermatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4370","DOI":"10.1016\/j.bmcl.2015.08.049","article-title":"Neutrophil elastase inhibitors for the treatment of (cardio)pulmonary diseases: Into clinical testing with pre-adaptive pharmacophores","volume":"25","author":"Li","year":"2015","journal-title":"Bioorganic. Med. Chem. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"726","DOI":"10.1124\/pr.110.002733","article-title":"Neutrophil elastase, proteinase 3, and cathepsin G as therapeutic targets in human diseases","volume":"62","author":"Korkmaz","year":"2010","journal-title":"Pharm. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"E73","DOI":"10.1002\/med.20247","article-title":"Targeting COPD: Advances on low-molecular-weight inhibitors of human neutrophil elastase","volume":"33","author":"Lucas","year":"2013","journal-title":"Med. Res. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1042\/bj3300897","article-title":"Cleavage of native type I collagen by human neutrophil elastase","volume":"330","author":"Kafienah","year":"1998","journal-title":"Biochem. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/0009-8981(90)90241-J","article-title":"Polymorphonuclear elastase in neonatal sepsis","volume":"193","author":"Tsaka","year":"1990","journal-title":"Clin. Chim. Acta"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1007\/BF00187079","article-title":"PMN elastase in bone and joint infections","volume":"18","author":"Peters","year":"1994","journal-title":"Int. Orthop."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"283","DOI":"10.2741\/1184","article-title":"Wound Healing: An Overview of Acute, Fibrotic and Delayed Healing","volume":"9","author":"Diegelmann","year":"2004","journal-title":"Front. Biosci. J. Virtual Libr."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1443","DOI":"10.1007\/s00253-016-7889-6","article-title":"Detection of human neutrophil elastase (HNE) on wound dressings as marker of inflammation","volume":"101","author":"Ferreira","year":"2017","journal-title":"Appl. Microbiol. Biotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"eabb7788","DOI":"10.1126\/sciadv.abb7788","article-title":"Design and tuning of ionic liquid\u2013based HNO donor through intramolecular hydrogen bond for efficient inhibition of tumor growth","volume":"6","author":"Lv","year":"2020","journal-title":"Sci. Adv."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"891","DOI":"10.1002\/jctb.2375","article-title":"Methods for stabilizing and activating enzymes in ionic liquids\u2014A review","volume":"85","author":"Zhao","year":"2010","journal-title":"J. Chem. Technol. Biotechnol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1429","DOI":"10.1039\/b706677p","article-title":"The third evolution of ionic liquids: Active pharmaceutical ingredients","volume":"31","author":"Hough","year":"2007","journal-title":"New J. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1038\/528188a","article-title":"Chemistry: Develop ionic liquid drugs","volume":"528","author":"Shamshina","year":"2015","journal-title":"Nature"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1215","DOI":"10.1039\/b925147b","article-title":"Confused ionic liquid ions\u2014a \u201cliquification\u201d and dosage strategy for pharmaceutically active salts","volume":"46","author":"Bica","year":"2010","journal-title":"Chem. Commun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1007\/s11095-009-0030-0","article-title":"Crystalline vs. Ionic Liquid Salt Forms of Active Pharmaceutical Ingredients: A Position Paper","volume":"27","author":"Stoimenovski","year":"2010","journal-title":"Pharm. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1039\/c2md00269h","article-title":"Development of novel ionic liquids based on ampicillin","volume":"3","author":"Ferraz","year":"2012","journal-title":"MedChemComm"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2011","DOI":"10.1039\/b923855g","article-title":"In search of pure liquid salt forms of aspirin: Ionic liquid approaches with acetylsalicylic acid and salicylic acid","volume":"12","author":"Bica","year":"2010","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1951","DOI":"10.1021\/bi00431a001","article-title":"Human leukocyte and porcine pancreatic elastase: X-ray crystal structures, mechanism, substrate specificity, and mechanism-based inhibitors","volume":"28","author":"Bode","year":"1989","journal-title":"Biochemistry"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1002\/cssc.201300459","article-title":"Toxicity of Ionic Liquids: Eco(cyto)activity as Complicated, but Unavoidable Parameter for Task-Specific Optimization","volume":"7","author":"Egorova","year":"2014","journal-title":"ChemSusChem"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.ijbiomac.2016.01.059","article-title":"Inhibitory effects of ionic liquids on the lactic dehydrogenase activity","volume":"86","author":"Dong","year":"2016","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.saa.2016.01.047","article-title":"Spectroscopic studies on the inhibitory effects of ionic liquids on lipase activity","volume":"159","author":"Fan","year":"2016","journal-title":"Spectrochim. Acta A Mol. Biomol. Spectrosc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.ecoenv.2014.10.029","article-title":"Cytotoxicity towards CCO cells of imidazolium ionic liquids with functionalized side chains: Preliminary QSTR modeling using regression and classification based approaches","volume":"112","author":"Das","year":"2015","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1016\/j.ijbiomac.2012.06.020","article-title":"Effect of ionic liquid on activity, stability, and structure of enzymes: A review","volume":"51","author":"Naushad","year":"2012","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/j.chemosphere.2016.12.138","article-title":"Assessment of ionic liquids\u2019 toxicity through the inhibition of acylase I activity on a microflow system","volume":"173","author":"Azevedo","year":"2017","journal-title":"Chemosphere"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.jhazmat.2016.02.005","article-title":"Automated cytochrome c oxidase bioassay developed for ionic liquids\u2019 toxicity assessment","volume":"309","author":"Costa","year":"2016","journal-title":"J. Hazard. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.bej.2015.03.005","article-title":"Key factors affecting the activity and stability of enzymes in ionic liquids and novel applications in biocatalysis","volume":"99","author":"Gao","year":"2015","journal-title":"Biochem. Eng. J."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10646-012-0997-x","article-title":"Designing ionic liquids: The chemical structure role in the toxicity","volume":"22","author":"Ventura","year":"2013","journal-title":"Ecotoxicology"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1039\/B712109A","article-title":"Qualitative and quantitative structure activity relationships for the inhibitory effects of cationic head groups, functionalised side chains and anions of ionic liquids on acetylcholinesterase","volume":"10","author":"Arning","year":"2008","journal-title":"Green Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1039\/B402348J","article-title":"Effects of Ionic Liquids on the Acetylcholinesterase \u2014A Structure-Activity Relationship Consideration","volume":"6","author":"Stock","year":"2004","journal-title":"Green Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1039\/b419172b","article-title":"Toxicity and antimicrobial activity of imidazolium and pyridinium ionic liquids","volume":"7","author":"Docherty","year":"2005","journal-title":"Green Chem."},{"key":"ref_31","unstructured":"Paul, T., Anastas, S., Peter, W., and Stark, A. (2013). Green Solvents: Ionic Liquids, John Wiley & Sons."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.molliq.2009.12.008","article-title":"Quantitative structure\u2013activity relationships (QSARs) to estimate ionic liquids ecotoxicity EC50 (Vibrio fischeri)","volume":"152","author":"Luis","year":"2010","journal-title":"J. Mol. Liq."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.jhazmat.2015.10.055","article-title":"Quaternary ammonium salts with tetrafluoroborate anion: Phytotoxicity and oxidative stress in terrestrial plants","volume":"304","author":"Biczak","year":"2016","journal-title":"J. Hazard. Mater."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1660","DOI":"10.1039\/b914284n","article-title":"Toxicological evaluation on human colon carcinoma cell line (CaCo-2) of ionic liquids based on imidazolium, guanidinium, ammonium, phosphonium, pyridinium and pyrrolidinium cations","volume":"11","author":"Frade","year":"2009","journal-title":"Green Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4095","DOI":"10.1039\/c3nj00731f","article-title":"Active pharmaceutical ingredients based on salicylate ionic liquids: Insights into the evaluation of pharmaceutical profiles","volume":"37","author":"Pinto","year":"2013","journal-title":"New J. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.jhazmat.2013.11.052","article-title":"Automated evaluation of pharmaceutically active ionic liquids\u2019 (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri","volume":"265","author":"Costa","year":"2014","journal-title":"J. Hazard. Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"742","DOI":"10.1021\/acs.biochem.7b00906","article-title":"Design of an Activity-Based Probe for Human Neutrophil Elastase: Implementation of the Lossen Rearrangement To Induce F\u00f6rster Resonance Energy Transfers","volume":"57","author":"Tikhomirov","year":"2018","journal-title":"Biochemistry"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1042\/BJ20061143","article-title":"The dependence of enzyme activity on temperature: Determination and validation of parameters","volume":"402","author":"Peterson","year":"2007","journal-title":"Biochem. J."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/1\/200\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:06:27Z","timestamp":1760159187000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/1\/200"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,2]]},"references-count":38,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["molecules26010200"],"URL":"https:\/\/doi.org\/10.3390\/molecules26010200","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,2]]}}}