{"title":"How Enzyme Selectivity and Immobilization Affect Catalytic Yields in Lipase-Catalyzed Processes","authors":"Ibrahim Karume","doi":"10.2174/0115701786330890240826053103","DOIUrl":"https://doi.org/10.2174/0115701786330890240826053103","url":null,"abstract":": Herein, the influence of structural attributes, including the interactions of lipases with support systems, substrates, products/byproducts, and the media environment, on enzyme stability, selectivity and activity are discussed. Substrates/products, such as methanol, glycerol, phenolic acids and polyphenols, can inhibit lipase activity by influencing the mass flow of the reactants and products or by enzyme denaturation, which is also caused by extreme pH, high temperatures, and digestive action of most organic solvents. Immobilization techniques that involve chemical bonding between the functional groups of the support and the amino acids of the lipase maintain the enzyme’s active conformation via the formation of stable secondary structures. Functionalized metal nanoparticles and metal and covalent organic frameworks (COFs and MOFs) covalently bond to lipases, reducing the reliance of the active site conformation on hydrogen bonding and disulfide bonds. The crystallinity of COFand MOF-immobilized lipases allows them to be used in contrasting media environments and at high temperatures, which increases the reaction kinetics and improves the catalytic yield. On the other hand, inert support systems such as silica promote catalytic yields by minimizing protein leaching, which fairly maintains the amount of the preloaded lipase. The structure of substrates also plays a large role, whereas some lipases strictly prefer narrow substrates. In contrast, others, such as Candida species lipases, are liberal and allow substrates of varying bulkiness/steric hindrances.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photochemical Dimerization of Indones: A DFT Study","authors":"Maurizio D' Auria","doi":"10.2174/0115701786313908240822100732","DOIUrl":"https://doi.org/10.2174/0115701786313908240822100732","url":null,"abstract":"In this study, DFT calculations were performed in order to identify the reaction products of the photochemical dimerization of indones. Calculations allowed us to assume that all tested reactions occurred in the first excited singlet state. The irradiation of 2-phenyl-5-nitroindone gave the main product, the <i>anti-cis</i> head-to-tail dimer, while the other two compounds found in the experiments were the <i>syn-cis</i> head-to-head dimer and the <i>anti-cis</i> head-to-tail dimer. The irradiation of 2-phenylindone gave the main product, <i>syn-cis</i>-head-to-tail dimer, while the minor products were <i>anti-cis</i>-head-to-tail and <i>anti-cis</i>-head-to-head dimer. The photochemical dimerization of 2-methyl-3-phenylindone gave the main product, <i>anti-cis</i>-head-to-tail dimer, while the minor component of the mixture was <i>syn-cis</i>-head- to-head dimer.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rapid and Metal-Free Green Synthesis of Coumarins Catalyzed by Humic Acid","authors":"Ling Wei, Yichun Wang, Qixuan Huang, Hongshe Wang","doi":"10.2174/0115701786318539240822112936","DOIUrl":"https://doi.org/10.2174/0115701786318539240822112936","url":null,"abstract":": In recent years, numerous methods have been developed for the synthesis of coumarins via Pechmann reaction catalyzed by various catalysts. Although each of the synthetic strategies previously reported has its own merit, most of these methods are associated with certain disadvantages, including the use of commercially unavailable metal catalysts and organic solvents, low yields, and long reaction times. Therefore, the development of a highly efficient, green, and sustainable catalytic methodology for the synthesis of coumarins is still desirable. Humic acid has been found to be an efficient catalyst for the synthesis of coumarins via the Pechmann reaction at 80oC under solvent-free conditions. The methodology enables the synthesis of structurally diverse coumarins from phenols and β-keto esters within 5-8 min in high yields (91-99%). The green, commercially available, inexpensive organocatalyst can be effectively recycled and reused five times with no significant dropdown in the yield of the product. The method reported has the advantages of high yield, no need for metal catalysts, short reaction time, simple operation, and green and reusable catalyst.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Efficient Metal-Free Methodology for the Synthesis of Hydrazo-Linked 5-(4-aryl)-1H-1,2,4-Triazoles","authors":"Neha Rani, Deepak K. Aneja, Mayank Kinger, Rinku Soni, Monika Sihag, Sandeep Malik, Kirti Bhardwaj","doi":"10.2174/0115701786332586240819074232","DOIUrl":"https://doi.org/10.2174/0115701786332586240819074232","url":null,"abstract":"Hydrazo compounds have displayed significant roles in both biological and physical aspects, such as spinamycin as a potent growth inhibitor against fungi and rat sarcoma cells, hydrazo tocopherol as a component of vitamin E, and electron-rich hydrazo-linked triazines as energetic materials. In this study, a metal-free approach was proposed for the synthesis of hydrazo-linked 5-(4- aryl)-1H-1,2,4-triazoles. The methods for the synthesis of 5-(4-aryl)-1H-1,2,4-triazoles initiated by the reaction of aldehyde with semicarbazide. The resulted compound, 5-(4-aryl)-1H-1,2,4-triazol-3- ol, upon reaction with phosphorous oxychloride yielded 3-chloro-5-(4-aryl)-1H-1,2,4-triazoles. These synthesized compounds upon fusión with various aryl and hetero aryl substituted hydrazines provided desired hydrazo moieties. Synthesized hydrazo compounds were characterized by spectroscopic techniques, viz. 1H-NMR, FT-IR and mass spectrometry. In this study, a series of novel hydrazo- linked 5-(4-aryl)-1H-1,2,4-triazoles were synthesized. The methodology proposed in this study eliminates the use of complicated procedures and heavy metals.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ce(OTf)3-Catalyzed Synthesis of Glucopyranurono-6,1-Lactone: A Key Intermediate for Obtaining Glycoconjugates of Peptidic Fragments of Arenastatin A","authors":"A. Mezrai, L. Mrah, Z. Khiati, A. Keniche","doi":"10.2174/0115701786325021240817182955","DOIUrl":"https://doi.org/10.2174/0115701786325021240817182955","url":null,"abstract":"In this work, 2,3,4-tri-O-acetyl-D-glucurono-6,1-lactone has been prepared from glucuronic acid in two steps by converting it into glucuronic anhydride. In the presence of a catalytic amount of Ce(OTf)3 (10 examples) in ethyl acetate, the glucuronic anhydride provided 6.1-lactone in good to excellent yields. This lactone was used to prepare the novel glycoconjugates of peptidic fragments of arenastatin A, a sponge cytotoxic depsipeptide, and its analogues.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Continuous Flow Synthesis of Amides in Bio-Derived Solvent GVL","authors":"Xu-Yang Mu, Rui Zhu, Li-Jie Yu, Wen-Long Wang","doi":"10.2174/0115701786313379240815113722","DOIUrl":"https://doi.org/10.2174/0115701786313379240815113722","url":null,"abstract":": The amide group is one of the most ubiquitous chemical motifs in the pharmaceutical field. An efficient continuous flow synthesis of amides was achieved by coupling acids with amines using 2-bromo-1-ethylpyridinium tetrafluoroborate (BEP) in the bio-derived “green” solvent γ- valerolactone (GVL). The reaction proceeded under mild reaction conditions (ambient temperature, 1 min) with simple filtration without the need for extensive purification, allowing a safe and ondemand generation of procainamide and VH032-Boc with a productivity of 0.44 g day-1 and 0.99 g day-1. The finding of our work aligned with green chemistry principles should result in its adoption by the chemistry community. other: No","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Shaiq Ali, Sumera Shezadi, Azra Akbar, Humaira Zafar, Muhammad Imran Malik, Mahreen Lateef
{"title":"One-Pot Syntheses and Enzyme Inhibition Studies of New C-28 Ester Derivatives of Betulinic Acid","authors":"Muhammad Shaiq Ali, Sumera Shezadi, Azra Akbar, Humaira Zafar, Muhammad Imran Malik, Mahreen Lateef","doi":"10.2174/0115701786324362240726102810","DOIUrl":"https://doi.org/10.2174/0115701786324362240726102810","url":null,"abstract":": Betulinic acid and its various synthetic derivatives have been reported to possess diverse biological activities and some of these may serve as useful therapeutic agents for a variety of human disorders. In this perspective, we have now developed convenient one-pot syntheses of new C-28 esters (2-7) of betulinic acid by esterification of the carboxylic moiety of betulinic acid (1) with various alkylating agents. All the target compounds were subjected to enzyme inhibition studies to ascertain their possible therapeutic utility. Compound 5 showed very potent lipoxygenase inhibitory activity with an IC50 value of 13.2 μM, being much lower than the IC50 value of 22.4 μM of baicalein, which was used as the standard. Butulinic acid itself and compound 6 also showed significant inhibitory potential (IC50: 32.4 and 25.1 μM) against the same enzyme. The activities of both compounds 5 and 6 have been justified by intensive docking studies. Compounds 2 and 3 exhibited substantial inhibition (IC50: 18.4 and 21.5 μM) against the enzyme butrylcholinesterase, compared to serine used as the standard (IC50: 7.8 μM).","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular Docking and Modelling Studies for Identifying Novel Oxadiazole Derivatives to Inhibit COX-2 Enzyme as an Anti-Inflammatory Treatment","authors":"Tarun Chaudhary, Prabhat Kumar Upadhyay, Ritu Kataria","doi":"10.2174/0115701786314768240726053647","DOIUrl":"https://doi.org/10.2174/0115701786314768240726053647","url":null,"abstract":"The objective of the study was to develop new Oxadiazole compounds using docking simulation studies for inhibitory action against the Cycloxoygenase-2(COX-2) enzyme. The study aimed at the development and identification of novel and potent derivatives of 1,3,4-oxadiazole for targeting anti-inflammatory disease by screening their inhibitory action against COX-2 enzyme with schrodinger molecular docking software and molecular simulation by GROMACS 2022. A library of 375 novel compounds of 1,3,4-oxadiazoles derivatives was designed and proposed for docking against cyclooxygenase-2 enzyme (COX-2)PDB ID: 6BL4, which was downloaded from protein data bank site https://www.rcsb.org/. MD simulations for three models were performed, namely, compound A-Cox-2, E-Cox-2, and G-Cox-2, for 100 ns. Out of 375 proposed compounds, the top 16 compounds with good docking scores and binding energy were selected for further ADME profile studies in which all compounds showed good results as compared to Standard drugs. RMSD values of 0.2 nm showed that all ligand-Cox-2 complexes were stable during simulation. Compound G was the most efficient in decent interactions with the residues ARG120 and TYR355 of cyclooxygenase- 2, which were stable for 29.32, 21.52, and 12.00% duration of simulation along with comparatively better h-bond contacts. All potential inhibitors met Lipinski's rule of five, indicating oral availability. The potential compounds may be further evaluated for pharmacological activities using different in vitro and in vivo evaluations.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Insight into the Various Synthetic Approaches of 1,3,4 and 1,2,4-Oxadiazole and its Derivatives, Along with their Remarkable Biological Activities","authors":"Sadhana Sharma, Chandana Majee, Rupa Mazumder, Kavita Rana, Swrupanjali Padhi, Avijit Mazumder, Saumya Das, Pankaj Kumar Tyagi, Sachin Kumar Singh","doi":"10.2174/0115701786318560240723060417","DOIUrl":"https://doi.org/10.2174/0115701786318560240723060417","url":null,"abstract":": Oxadiazole is an organic compound featuring a heterocyclic ring housing carbon, oxygen, and nitrogen atoms. Due to their heightened stability in biological environments, oxadiazole rings exhibit significant biological activities, effectively addressing health challenges like infectious diseases and chronic conditions in medicinal chemistry. The main objective of this review is to discuss various synthetic approaches related to oxadiazole and its derivatives, along with their biological activities. The diverse reactivity positions oxadiazole as a valuable building block in organic synthesis, with derivatives exhibiting promising pharmacological activities. It involves a systematic literature review, critical analysis, and synthesis of existing research. This review comprises the everexpanding chemical knowledge but also holds significant implications for drug development. The various synthetic approaches, such as Suzuki-Miyaura, Stille coupling [3+2] cycloaddition reaction, and many more methods used for the synthesis of oxadiazole through different schemes, have been discussed thoroughly. This review also concisely associated the pharmacological activities of new oxadiazole and its derivatives, such as prenoxdiazine, dapagliflozin, nesapidil, pleconaril, and so on. This review highlights the importance of continued research into the structure-activity relationships of oxadiazole derivatives, paving the way for developing novel and more potent therapeutic agents.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficient Green Synthesis and Characterization of Benzil and its Derivatives Using Microwave Irradiation","authors":"Krina Patel, Drashti Shah, Dev Jani, Neel Savaliya, Dharti Patel, Ashish Shah, Pinkal Patel, Ashish Patel","doi":"10.2174/0115701786308700240801062008","DOIUrl":"https://doi.org/10.2174/0115701786308700240801062008","url":null,"abstract":": The main aim of the present work was to conduct the one-pot microwave-assisted green synthesis of benzil and its derivatives. Benzil is acknowledged as a pivotal scaffold in the realm of medicinal and organic chemistry, owing to its extensive utilities. Due to the various merits of the green technology approach compared to classical methodology and the provision of sustainable chemistry, this reaction has received renewed interest for preparing benzil derivatives in an environmentally friendly manner with improved yields. We have, herein, presented a highly efficient route for the synthesis of benzil derivatives utilizing acetophenone and benzene derivatives as primary substrates. Notably, this synthesis obviates the necessity for any potentially hazardous catalyst and employs microwave irradiation and iodine green oxidant to facilitate the reaction. All synthesized compounds were characterized by spectroscopic techniques, such as IR, 1H NMR, and mass spectrometry. A green and efficient microwave-assisted synthesis methodology for benzil and its derivatives has been developed using iodine green oxidant. This approach has yielded the desired benzil derivatives with remarkable efficiency, achieving yields ranging from 91% to 97% within a short time of 10-15 minutes; the derivatives have been characterized using spectral techniques, viz., IR, 1H NMR, and mass spectrometry. It is noteworthy that the entire reaction optimization process has been conducted in an environmentally friendly manner, thereby exemplifying a synthetic methodology being both environmentally sustainable and economically viable, compared to conventional techniques.","PeriodicalId":18116,"journal":{"name":"Letters in Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}