@article {47473, title = {Morphological and molecular characterization of Penicillium rubens sp.nov isolated from poultry feed}, journal = {Indian Phytopathology}, volume = {72}, year = {2019}, month = {SEP}, pages = {461{\textendash}478}, type = {Article}, abstract = {Fungi are the second largest group of eukaryotic organisms, estimates ranging from 2.2 to 3.8 million and 120,000 currently accepted species. Unfortunately, identification of Penicillium species is an overwhelming task even for taxonomic experts. In the current study, we isolated identified and morphologically characterized Penicillium rubens strain NCIM-1397. Molecular characterization of P. rubens by multilocus sequence analysis (MLSA) of internal transcribed spacer (ITS) region, β-tubulin (BenA), calmodulin (CaM), NL (D1/D2 region) and LR (large subunit region) gene. Conversely, BenA gene differentiated P. rubens from P. chrysogenum. Moreover, Vitek MS, Matrix-assisted laser desorption ionization{\textendash}time of flight mass spectrometer (MALDI-TOF{\textendash}MS) failed to discriminate to strain level. Metabolic profiling of P. rubens enable to produce roquefortine C, chrysogine, meleagrine, sorbicillin and non-producers for industrially important metabolite, penicillin determined by LC{\textendash}MS. Even, In addition, even molecular detection of penicillin biosynthetic pathway genes, PcbC, PenDE and Phl were negative by PCR. Nevertheless, P. rubens showed 90{\textendash}100\% toxicity/pathogenicity on seed germination of sorghum (Sorghum bicolor) and no further development of coleoptiles, radicle and leaf length observed. Also, it showed non-toxic to animal cell determined on Human foreskin fibroblast (HFF) cell line by In-Vitro.}, doi = {10.1007/s42360-019-00165-2}, author = {Sawant, Amol M. and Vankudoth, Ramu and Navale, Vishwambar and Kumavat, Rajkamal and Kumari, Prabla and Santhakumari, B. and Vamkudoth, Koteswara Rao} } @article {46632, title = {Process development for 6-aminopenicillanic acid production using lentikats-encapsulated escherichia coli cells expressing penicillin V acylase}, journal = {ACS Omega}, volume = {5}, year = {2020}, month = {NOV }, pages = {28972-28976}, type = {Article}, abstract = {

Penicillin V acylase (PVA, EC 3.5.1.11) hydrolyzes the side chain of phenoxymethylpenicillin (Pen V) and finds application in the manufacture of the pharmaceutical intermediate 6-aminopenicillanic acid (6-APA). Here, we report the scale-up of cultivation of Escherichia coli whole cells expressing a highly active PVA from Pectobacterium atrosepticum and their encapsulation in polyvinyl alcohol-poly(ethylene glycol) Lentikats hydrogels. A biocatalytic process for the hydrolysis of 2\% (w/v) Pen V was set up in a 2 L reactor using the Lentikats-immobilized whole cells, with a customized setup to enable continuous downstream processing of the reaction products. The biocatalytic reaction afforded complete conversion of Pen V for 10 reaction cycles, with an overall 90\% conversion up to 50 cycles. The bioprocess was further scaled up to the pilot-scale at 10 L, enabling complete conversion of Pen V to 6-APA for 10 cycles. The 6-APA and phenoxy acetic acid products were recovered from downstream processing with isolated yields of 85-90 and 87-92\%, respectively. Immobilization in Lentikats beads improved the stability of the whole cells on storage, maintaining 90-100\% activity and similar conversion efficiency after 3 months at 4 degrees C. The robust PVA biocatalyst can be employed in a continuous process to provide a sustainable route for bulk 6-APA production from Pen V.

}, issn = {2470-1343}, doi = {10.1021/acsomega.0c02813}, author = {Sawant, Amol M. and Sunder, Avinash Vellore and Vamkudoth, Koteswara Rao and Ramasamy, Sureshkumar and Pundle, Archana} } @article {47452, title = {Aspergillus derived mycotoxins in food and the environment: prevalence, detection, and toxicity}, journal = {Toxicology Reports }, volume = {8}, year = {2021}, month = {JAN}, pages = {1008-1030}, type = {Article}, abstract = {

Aspergillus\ species are the paramount ubiquitous fungi that contaminate various food substrates and produce biochemicals known as mycotoxins. Aflatoxins (AFTs), ochratoxin A (OTA), patulin (PAT), citrinin (CIT), aflatrem (AT), secalonic acids (SA), cyclopiazonic acid (CPA), terrein (TR), sterigmatocystin (ST) and gliotoxin (GT), and other toxins produced by species of\ Aspergillus\ plays a major role in food and human health. Mycotoxins exhibited wide range of toxicity to the humans and animal models even at nanomolar (nM) concentration. Consumption of detrimental mycotoxins adulterated foodstuffs affects human and animal health even trace amounts. Bioaerosols consisting of spores and hyphal fragments are active elicitors of bronchial irritation and allergy, and challenging to the public health.\ Aspergillus\ is the furthermost predominant environmental contaminant unswervingly defile lives with a 40{\textendash}90 \% mortality risk in patients with conceded immunity. Genomics, proteomics, transcriptomics, and metabolomics approaches useful for mycotoxins{\textquoteright} detection which are expensive. Antibody based detection of toxins chemotypes may result in cross-reactivity and uncertainty. Aptamers (APT) are single stranded DNA (ssDNA/RNA), are specifically binds to the target molecules can be generated by systematic evolution of ligands through exponential enrichment (SELEX). APT are fast, sensitive, simple, in-expensive, and field-deployable rapid point of care (POC) detection of toxins, and a better alternative to antibodies.

}, doi = {10.1016/j.toxrep.2021.04.013}, author = {Navale, Vishwambar and Vamkudoth, Koteswara Rao and Ajmera, Shanthipriya and Dhuri, Vaibhavi} } @article {48093, title = {Assembly, annotation, and comparative whole genome sequence of fusarium verticillioides isolated from stored maize grains}, volume = {11}, year = {2022}, month = {JUL}, pages = {810}, type = {Article}, abstract = {

Fusarium verticillioides is a plant pathogenic fungus affecting a wide range of crops worldwide due to its toxigenic properties. F. verticillioides BIONCL4 strain was isolated from stored maize grain samples in India, and produces high amount of fumonisin B1 (FB1). We report a comparative genomic analysis of F. verticillioides, covering the basic genome information, secretome, and proteins involved in host-pathogen interactions and mycotoxin biosynthesis. Whole-genome sequencing (WGS) was performed using the Illumina platform with an assembly size of 42.91 Mb, GC content of 48.24\%, and 98.50\% coverage with the reference genome (GCA000149555). It encodes 15,053 proteins, including 2058 secretory proteins, 676 classical secretory proteins, and 569 virulence and pathogenicity-related proteins. There were also 1447 genes linked to carbohydrate active enzymes (CaZymes) and 167 genes related to mycotoxin production. Furthermore, F. verticillioides genome comparison revealed information about the species{\textquoteright} evolutionary history. The overall study helps in disease prevention and management of mycotoxins to ensure food safety.

}, keywords = {comparative genomics, Fusarium verticillioides, mycotoxin biosynthesis, plant-pathogen interaction, Secretome, whole-genome sequencing}, doi = {10.3390/pathogens11070810}, author = {Navale, Vishwambar D. and Sawant, Amol M. and Gowda, Varun U. and Vamkudoth, Koteswara Rao} } @article {47900, title = {Biosynthetic process and strain improvement approaches for industrial penicillin production}, journal = {Biotechnology Letters}, volume = {44}, year = {2022}, month = {FEB}, pages = {179-192}, type = {Review}, abstract = {

Penicillins and cephalosporins are the most important class of beta (beta) lactam antibiotics, accounting for 65\% total antibiotic market. Penicillins are produced by Penicillium rubens (popularly known as P. chrysogenum) were used to synthesize the active pharmaceutical intermediate (API), 6-aminopenicillinic acid (6-APA) employed in semisynthetic antibiotic production. The wild strains produce a negligible amount of penicillin (Pen). High antibiotic titre-producing P. chrysogenum strains are necessitating for industrial Pen production to meet global demand at lower prices. Classical strain improvement (CSI) approaches such as random mutagenesis, medium engineering, and fermentation are the cornerstones for high-titer Pen production. Since, Sir Alexander Fleming Discovery of Pen, great efforts are expanded to develop at a commercial scale antibiotics producing strains. Breakthroughs in genetic engineering, heterologous expression and CRISPR/Cas9 genome editing tools opened a new window for Pen production at a commercial scale to assure health crisis. The current state of knowledge, limitations of CSI and genetic engineering approaches to Pen production are discussed in this review.

}, keywords = {beta-lactam antibiotic, Classical strain improvement (CSI), Genetic engineering, Penicillin, Penicillium chrysogenum}, issn = {0141-5492}, doi = {10.1007/s10529-022-03222-5}, author = {Sawant, Amol M. and Vamkudoth, Koteswara Rao} } @article {48357, title = {Maltooligosaccharide forming amylases and their applications in food and pharma industry}, journal = {Journal of Food Science and Technology-Mysore}, volume = {59}, year = {2022}, month = {OCT}, pages = {3733-3744}, type = {Review}, abstract = {

Oligosaccharides are low molecular weight carbohydrates with a wide range of health benefits due to their excellent bio-preservative and prebiotic properties. The popularity of functional oligosaccharides among modern consumers has resulted in impressive market demand. Organoleptic and prebiotic properties of starch-derived oligosaccharides are advantageous to food quality and health. The extensive health benefits of oligosaccharides offered their applications in the food, pharmaceuticals, and cosmetic industry. Maltooligosaccharides and isomaltooligosaccharides comprise 2-10 glucose units linked by alpha-1-4 and alpha-1-6 glycoside bonds, respectively. Conventional biocatalyst-based oligosaccharides processes are often multi-steps, consisting of starch gelatinization, hydrolysis and transglycosylation. With higher production costs and processing times, the current demand cannot meet on a large-scale production. As a result, innovative and efficient production technology for oligosaccharides synthesis holds paramount importance. Malto-oligosaccharide forming amylase (EC 3.2.1.133) is one of the key enzymes with a dual catalytic function used to produce oligosaccharides. Interestingly, Malto-oligosaccharide forming amylase catalyzes glycosidic bond for its transglycosylation to its inheritance hydrolysis and alternative biocatalyst to the multistep technology. Genetic engineering and reaction optimization enhances the production of oligosaccharides. The development of innovative and cost-effective technologies at competitive prices becomes a national priority.

}, keywords = {Glycosyl hydrolases, Isomaltooligosaccharides, Maltooligosaccharide, Maltooligosaccharide forming amylase, Transglycosylation}, issn = {0022-1155}, doi = {10.1007/s13197-021-05262-7}, author = {Shinde, Vidhya K. and Vamkudoth, Koteswara Rao} } @article {47777, title = {One-pot concurrent biosynthesis of biphasic CuxO (cuprous and cupric oxide) nanoparticles using leaf extract of Eichhornia crassipes and investigation of their potent healthcare applications}, journal = {Emergent Materials}, year = {2022}, month = {FEB}, type = {Article}, abstract = {Eichhornia crassipes, an aquatic weed, has been used for the one-pot quick synthesis of cuprous and cupric oxide nanoparticles in this report. The identification and validation of the formed nanoparticles were successfully done by sophisticated characterization techniques such as UV{\textendash}visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Their biomedical interventions were assessed by their antioxidant and anticancer activities. The synthesized nanoparticles have a spherical morphology with an average diameter of 10~nm. Antioxidant assay performed showed an increasing trend in a dose-dependent manner with the percentage radical scavenging activity up to 94.70\% at a much higher concentration of 1000~{\textmu}g/ml. The antioxidant potential at such higher concentration is suspected to invoke a change in the cytotoxic potential of the nanoparticles which is then verified by the MTT assay. A significant cytotoxic activity against HeLa (cervical cancer) and HCT 116 (colorectal carcinoma) cell lines was detected with noted IC50 values of 17.17 and 13.70~{\textmu}g/ml respectively. The conclusive findings obtained are enough to substantiate the use of these nanoparticles in biomedical areas specifically in anticancer treatment due to their high toxicities. The hazards imposed by Eichhornia crassipes can be alleviated by using them as biofactories for the synthesis of a variety of nanomaterials. This helps in curbing the water pollution issues as well as the developing synthesis protocols for robust and stable nanoparticles.}, isbn = {2522-574X}, doi = {10.1007/s42247-022-00347-1}, url = {https://doi.org/10.1007/s42247-022-00347-1}, author = {Moudgil, Aliesha and Varma, Sanjana and Shinde, Manish D. and Vamkudoth, Koteswara Rao and Sarkar, Dhiman M. and Shende, Rajnigandha A. and Amalnerkar, Dinesh and Chaudhari, Bhushan P.} } @article {48427, title = {Pectinase production by aspergillus niger and its applications in fruit juice clarification}, journal = {Journal of Pure and Applied Microbiology}, volume = {16}, year = {2022}, month = {NOV}, pages = {2724-2737}, type = {Article}, abstract = {

Pectinases (EC 3.2.1.15) are a class of enzymes that catalyze the depolymerization or de-esterification reactions that degrade pectic substances. In the present study, we have isolated the\ Aspergillus niger\ strain from soil samples, in India and evaluated pectinase production. The highest pectinase producing\ A. niger\ strain was further evaluated and optimized with various agricultural wastes. Plackett-Burman design (PBD) and Central composite design {\textquoteleft}(CCD){\textquoteright} were used to determine the best parameters for maximum pectinase production. Pectinase activity was increased to 99.21 U/ml after optimizing the production medium using PBD and CCD statistical analysis. A positive correlation of pectinase activity between predicted (112.65 U/ml) and experimental (99.21 U/ml with SD=0.005) optimum was observed. Maximum pectinase was produced by\ A. niger\ under submerged fermentation, utilizing orange peel, which is a cost-effective, adaptable, and environmentally friendly approach. The partially purified pectinase showed significant application for apple juice clarification and showed the ability to degrade pectin and therefore the colour change was observed in apple juice within 120 min. Maximum pectinase was produced by\ A. niger\ using agricultural waste orange peel under submerged fermentation which is an economical, versatile and eco-friendly process and pectinase showed a significant application for apple juice clarification.

}, doi = {10.22207/JPAM.16.4.43}, author = {Wagh, Vrushali and Patel, Hirvitaben and Patel, Nafisa and Vamkudoth, Koteswara Rao and Ajmera, Shanthipriya} } @article {48035, title = {Toxicity and preventive approaches of Fusarium derived mycotoxins using lactic acid bacteria: state of the art}, journal = {Biotechnology Letters}, volume = {44}, year = {2022}, month = {OCT}, pages = {1111-1126}, type = {Review}, abstract = {

Mycotoxin contamination of food and feed is a serious food safety issue and causes acute and chronic diseases in humans and livestock. Climatic and agronomic changes helps in the proliferation of fungal growth and mycotoxin production in food commodities. Mycotoxin contamination has attracted global attention due to its wide range of toxicity to humans and animals. However, physical and chemical management approaches in practice are unsafe for well-being due to their health-hazardous nature. Various antibiotics and preservatives are in use to reduce the microbial load and improve the shelf life of food products. In addition, the use of antibiotic growth promotors in livestock production may increase the risk of antimicrobial resistance, which is a global health concern. Due to their many uses, probiotics are helpful microbes that have a significant impact on food and nutrition. Furthermore, the probiotic potential of lactic acid bacteria (LAB) is employed in various food and feed preparations to neutralize mycotoxins, antimicrobial activities, balance the gut microbiome, and various immunomodulatory activities in both humans and livestock. In addition, LAB produces various antimicrobials, flavouring agents, peptides, and proteins linked to various food and health care applications. The LAB-based processes for mycotoxin management are more effective, eco-friendly, and low-cost than physical and chemical approaches. The toxicity, novel preventive measures, binding nature, and molecular mechanisms of mycotoxins{\textquoteright} detoxification using LAB have been highlighted in this review.

}, keywords = {Food safety, Fusarium species, Lactic acid bacteria, management, Mycotoxin}, issn = {0141-5492}, doi = {10.1007/s10529-022-03293-4}, author = {Navale, Vishwambar D. and Vamkudoth, Koteswara Rao} } @article {48749, title = {Biosynthesis of gold nanoparticles by Penicillium rubens and catalytic detoxification of ochratoxin A and organic dye pollutants}, journal = {International Microbiology}, volume = {26}, year = {2023}, month = {NOV}, pages = {765-780}, type = {Article}, abstract = {

The environmental pollution caused by chemical dyes is a growing concern nowadays. Limitations of traditional methods opened the route for nanotechnology; owing to the versatile properties of nanomaterials, gold nanoparticles (AuNPs) became a potential strategy for different applications. In the present study, biosynthesis of gold nanoparticles (BioAuNPs) was carried out by reacting chloroauric acid (HAuCl4) with cell-free filtrate of Penicillium rubens sp. nov. NCIM 1937. The AuNPs were then characterized by UV-visible spectroscopy, HR-TEM, FTIR, and DLS analysis to further examine their efficacious biosynthesis and morphological properties including size, shape, and stability. The biogenic AuNPs are polydisperse in nature, with a mean size of 14.92 +/- 5 nm. These AuNPs exhibited promising antimicrobial activity against Escherichia coli NCIM-2065, Bacillus subtilis NCIM-2010, and Penicillium verrucosum MTCC 4935. In vitro quantitative HPLC results revealed that BioAuNPs significantly inhibited the biosynthesis of ochratoxin A (OTA). Microbial fuel cells (MFCs) are intriguing for power generation and wastewater treatment since they can directly transform chemical energy stored in organic matter to electricity by extracellular electron transfer (EET) via membrane proteins. AuNPs also showed excellent potential for dye degradation of organic pollutants, viz., methylene blue (MB), phenol red (PR), bromothymol blue (BTB), Congo red (CR), and 4-nitrophenol (4-NP). All dye removal efficiencies were estimated and fitted to pseudo-first-order processes using kinetic rate constants (Ka).The present study reveals a simple, original, and eco-friendly method for the synthesis of multifunctional biogenic AuNPs that could be effective in OTA detoxification in food products and organic pollutant removal during wastewater treatment for a sustainable environment.

}, keywords = {Catalytic organic dye degradation, gold nanoparticles, Ochratoxin A, Penicillium rubens, Penicillium verrucosum}, issn = {1139-6709}, doi = {10.1007/s10123-023-00341-5}, author = {Bhandari, Yogesh and Varma, Sanjana and Sawant, Amol and Beemagani, Sreelatha and Jaiswal, Neha and Chaudhari, Bhushan P. and Vamkudoth, Koteswara Rao} } @article {48298, title = {Genetic diversity of toxigenic Fusarium verticillioides associated with maize grains, India}, journal = {Genetics and Molecular Biology}, volume = {46}, year = {2023}, month = {MAY}, pages = {e20220073}, type = {Article}, abstract = {

In the present investigation, prevalence, genetic diversity, and mycotoxin producing potential of Fusarium species associated with maize grain samples were studied from different geographical regions of India. The highest prevalence of Fusarium verticillioides was recorded as 88.52\%, followed by F. coffeatum, F. foetens, and F. euwallaceae, 6.55\%, 3.27\%, and 1.63\%, respectively. We isolated 54 strains of F. verticillioides, and their genetic diversity was studied by inter simple sequence repeats (ISSR). The ISSR fingerprints (AG) 8C and (AG) 8G showed 252 and 368 microsatellite sites in the genome of F. verticillioides and resulted in 99-100\% repeatability and reproducibility. The Simpson (SID) and Shannon (H) indices (0.78 and 2.36) suggest that F. verticillioides strains exhibit moderate to high diversity. Molecular detection of fumonisin B1 (FB1) biosynthetic genes (FUM1 and FUM13) involved in FB1 production in F. verticillioides was confirmed by polymerase chain reaction (PCR). Furthermore, 91\% of the strains were positive for FB1 production, which was affirmed by liquid chromatography with tandem mass spectrometry (LC-MS-MS). In-vitro appurtenance of F. verticillioides spores exhibited a high to moderate effect on the growth and development of the maize. The current finding demonstrated that most F. verticillioides strains showed a wide range of genetic diversity with varied toxigenic and pathogenic potentials. In conclusion, for the first time, F. coffeatum, F. foetens, and F. euwallaceae species were reported from maize grain samples in India. They were positive for FB1 and negatively affecting grain quality, which is a major concern in food safety.

}, keywords = {diversity, Food safety, Fusarium verticillioides, Mycotoxin, pathogenicity}, issn = {1415-4757}, doi = {10.1590/1678-4685-GMB-2022-0073}, author = {Navale, Vishwambar D. and Sawant, Amol M. and Vamkudoth, Koteswara Rao} } @article {48717, title = {Isolation and molecular characterization of indigenous penicillium chrysogenum/rubens strain portfolio for penicillin V production}, journal = {Microorganisms}, volume = {11}, year = {2023}, month = {APR}, pages = {1132}, type = {Article}, abstract = {

Beta (beta)-lactam antibiotic is an industrially important molecule produced by Penicillium chrysogenum/rubens. Penicillin is a building block for 6-aminopenicillanic acid (6-APA), an important active pharmaceutical intermediate (API) used for semi-synthetic antibiotics biosynthesis. In this investigation, we isolated and identified Penicillium chrysogenum, P. rubens, P. brocae, P. citrinum, Aspergillus fumigatus, A. sydowii, Talaromyces tratensis, Scopulariopsis brevicaulis, P. oxalicum, and P. dipodomyicola using the internal transcribed spacer (ITS) region and the beta-tubulin (BenA) gene for precise species identification from Indian origin. Furthermore, the BenA gene distinguished between complex species of P. chrysogenum and P. rubens to a certain extent which partially failed by the ITS region. In addition, these species were distinguished by metabolic markers profiled by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Secalonic acid, Meleagrin, and Roquefortine C were absent in P. rubens. The crude extract evaluated for PenV production by antibacterial activities by well diffusion method against Staphylococcus aureus NCIM-2079. A high-performance liquid chromatography (HPLC) method was developed for simultaneous detection of 6-APA, phenoxymethyl penicillin (PenV), and phenoxyacetic acid (POA). The pivotal objective was the development of an indigenous strain portfolio for PenV production. Here, a library of 80 strains of P. chrysogenum/rubens was screened for PenV production. Results showed 28 strains capable of producing PenV in a range from 10 to 120 mg/L when 80 strains were screened for its production. In addition, fermentation parameters, precursor concentration, incubation period, inoculum size, pH, and temperature were monitored for the improved PenV production using promising P. rubens strain BIONCL P45. In conclusion, P. chrysogenum/rubens strains can be explored for the industrial-scale PenV production.

}, keywords = {beta-tubulin gene, high-performance liquid chromatography, internal transcribed spacer region, Penicillium chrysogenum/rubens, phenoxymethyl penicillin}, doi = {10.3390/microorganisms11051132}, author = {Sawant, Amol M. and Navale, Vishwambar D. and Vamkudoth, Koteswara Rao} } @article {48733, title = {Metabolites from lactococcus lactis subsp. lactis: isolation, structure elucidation, and antimicrobial activity}, journal = {ACS Omega}, volume = {8}, year = {2023}, month = {SEP}, pages = {36628-36635}, type = {Article}, abstract = {

Herein, we disclose the identification of novel metabolites from a potential probiotic strain, Lactococcus lactis subsp. lactis, obtained from traditional dairy milk samples collected in Maharashtra, India (in January 2021). Isolated metabolites include pyrazin-2-carboxamide [1, pyrazinamide, a potential antitubercular drug], 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one (2, DDMP), 2,4-di-tert-butylphenol (3), and hexadecanoic acid (4, palmitic acid). The chemical structures of these metabolites were elucidated through extensive 1D NMR (H-1 and C-13) and 2D NMR (HSQC, HMBC, and NOESY) analyses, high-resolution mass spectrometry, high-performance liquid chromatography, and single-crystal X-ray crystallography. Furthermore, these novel metabolites exhibited potent inhibitory activities against various bacteria, fungi, and yeast strains with minimum inhibitory concentrations ranging between 1.56 and 25 mu g/mL, and compounds 1 and 3 were found to be most active against a wide range of microbial strains tested.

}, issn = {2470-1343}, doi = {10.1021/acsomega.3c01662}, author = {Navale, Vishwambar D. and Borade, Balasaheb R. and Rama Krishna, Gamidi and Vamkudoth, Koteswara Rao and Kontham, Ravindar} } @article {48668, title = {Total synthesis, structure elucidation and expanded bioactivity of icosalide A: effect of lipophilicity and ester to amide substitution on its bioactivity}, journal = {Organic \& Biomolecular Chemistry}, volume = {21}, year = {2023}, month = {JUL}, pages = {5725-5731}, type = {Article}, abstract = {

The first total synthesis of icosalide A, an antibacterial depsipeptide that is unique in that it contains two lipophilic beta-hydroxy acids, has been achieved by following Fmoc solid-phase peptide synthesis in combination with solution-phase synthesis. The ambiguity in the absolute stereochemistry of icosalide A has been resolved by synthesizing the reported structures and other relevant diastereomers of icosalides and comparing their NMR data. NMR-based structure elucidation of icosalide A revealed a well-folded structure with cross-strand hydrogen bonds similar to the anti-parallel beta-sheet conformation in peptides and displayed a synergistic juxtaposition of the aliphatic sidechains. 12 analogues of icosalide A were synthesized by varying the constituent lipophilic beta-hydroxy acid residues, and their biological activities against Bacillus thuringiensis and Paenibacillus dendritiformis were explored. Most of these icosalide analogues showed an MIC of 12.5 \& mu;g mL(-1) against both bacteria. Swarming inhibition by icosalides was least in B. thuringiensis (8.3\%) compared to that in P. dendritiformis (33\%). Furthermore, this is the first report of icosalides showing assured inhibitory action (MIC between 2 and 10 \& mu;g mL(-1)) against the active stage of Mycobacterium tuberculosis and cancer cell lines such as HeLa and ThP1. This study could help optimize icosalides for anti-TB, antibacterial, and anti-cancer activities.

}, issn = {1477-0520}, doi = {10.1039/d3ob00809f}, author = {Dangi, Abha and Pande, Bharat and Agrawal, Sonia and Sarkar, Dhiman and Vamkudoth, Koteswara Rao and Marelli, Udaya Kiran} }