coatings Article Validating Anti-Infective Activity of Pleurotus Opuntiae via Standardization of Its Bioactive Mycoconstituents through Multimodal Biochemical Approach Aprajita Tiwari Pandey 1 , Ishan Pandey 2 , Anurag Kanase 3 , Amita Verma 4 , Beatriz Garcia-Canibano 5 , Sarada Prasad Dakua 6 , Shidin Balakrishnan 6, * and Mohan Prasad Singh 1, *   Citation: Tiwari Pandey, A.; Pandey, I.; Kanase, A.; Verma, A.; Garcia-Canibano, B.; Dakua, S.P.; Balakrishnan, S.; Singh, M.P. Validating Anti-Infective Activity of Pleurotus Opuntiae via Standardization of Its Bioactive Mycoconstituents through Multimodal Biochemical Approach. Coatings 2021, 11, 484. https:// doi.org/10.3390/coatings11040484 Academic Editor: Diana Anderson Received: 19 March 2021 Accepted: 17 April 2021 Published: 20 April 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Centre of Biotechnology, Nehru Science Complex, University of Allahabad, Prayagraj 211002, India; tiwari.aprajita2011@gmail.com 2 Department of Pathology, Motilal Nehru Medical College, Prayagraj 211001, India; ishan.pandey411@gmail.com 3 Department of Bioengineering, Northeastern University, Boston, MA 02115, USA; kanase.a@northeastern.edu 4 Bioorganic and Medicinal Chemistry Research Laboratory, Department of Pharmaceutical Science, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj 211007, India; amitaverma.dr@gmail.com 5 Neurosciences Institute, Hamad Medical Corporation, Doha 3050, Qatar; BCanibano@hamad.qa 6 Department of Surgery, Hamad Medical Corporation, Doha 3050, Qatar; SDakua@hamad.qa * Correspondence: sbalakrishnan1@hamad.qa (S.B.); mpsingh.16@gmail.com (M.P.S.) Abstract: Mushrooms produce a variety of bioactive compounds that are known to have anti- pathogenic properties with safer and effective therapeutic effects in human disease prognosis. The antibacterial activity of ethanol and methanol extracts of Pleurotus opuntiae were checked against pathogenic microorganisms viz. Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis NCIM 2300, Proteus vulgaris NCIM 5266, Serratia marcescens NCIM 2078, Shigella flexeneri NCIM 5265, Moraxella sp. NCIM 2795, Staphylococcus aureus ATCC 25923 by agar well diffusion method at different con- centrations of the extracts. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts was determined by INT (Iodonitrotetrazolium chloride) colori- metric assay. Extracts were standardized by thin layer chromatography (TLC) in different solvent systems. The Retention factors (Rf) of different compounds were calculated by high performance TLC (HPTLC) fingerprinting at UV 254, 366, and 540 nm before and after derivatization. The ethanol and methanol extracts of P. opuntiae showed bactericidal activity against all the test pathogens at MIC values of 15.6 to 52.08 mg/mL and 20.81 to 52.08 mg/mL respectively. Whereas the MBC values for ethanol and methanol extract of P. opuntiae against all pathogens were recorded as 26.03 to 62.5 mg/mL and 125 mg/mL respectively. Preliminary mycochemical screening of both the extracts revealed high contents of bioactive compounds. Amongst all the solvent systems used in TLC, the best result was given by chloroform + hexane (8:2) which eluted out 5 different compounds (spots). HPTLC results revealed spots with different Rf values for all the 24 compounds present. Thus, it can be inferred from the present investigation that the mycoconstituents could be an alternative medica- tion regimen and could play a role in new drug discoveries against different infections. Further, the antimicrobial components of these mushrooms can be transformed to bioengineered antimicrobial coatings for surfaces, drug and other hybrid systems for public health implications in combating persistent infections. Keywords: antimicrobial activity; mushroom; Pleurotus opuntiae; mycoconstituents; microorgan- isms; compounds 1. Introduction Antimicrobial resistance amongst infective bacterial communities poses a serious threat related to increased morbidity and mortality [1]. Resistance to popular antimicrobial Coatings 2021, 11, 484. https://doi.org/10.3390/coatings11040484 https://www.mdpi.com/journal/coatings