Inhibition Of Ca2 Research Articles

Exploring the binding mode of phenyl and vinyl boronic acids to human carbonic anhydrases

Boronic acids are an interesting but still poorly studied class of carbonic anhydrase inhibitors. Previous investigations proved that derivatives incorporating aromatic, arylalkyl, and arylalkenyl moieties are low micromolar to millimolar inhibitors for several α- and β-CAs involved in pathologic states.Here we report a high-resolution X-ray study on two classes of boronic acids (phenyl and vinyl) in complex with hCA II. Our results unambiguously clarify the binding mode of these molecules to the human carbonic anhydrase active site, which occurs through their tetrahedral anionic form, regardless of the nature of the organic scaffold. Data here presented contribute to the understanding of the inhibition mechanism of boronic acids that can be fruitfully used for the rational design of novel and effective isozyme-specific carbonic anhydrase inhibitors.

Synthesis and investigation of selective human carbonic anhydrase IX, XII inhibitors using coumarins bearing a sulfonamide or biotin moiety

The role of carbonic anhydrases isoforms (CAs) IX and XII in the pathogenesis and progression of many types of solid tumors is well known. In this context, selective CA inhibitors (CAIs) towards the mentioned isoforms is a validated strategy for the development of agents to target cancer. For this purpose, novel coumarin derivatives based on the hybridization with arylsulfonamide or biotin scaffolds were synthesized and tested as inhibitors of four different human carbonic anhydrases isoforms: hCA I, II, IX and XII. Coumarin-sulfonamide derived 27, with a thiourea moiety and triazole as linker, showed the highest inhibition activity against hCA XII with an inhibition constant (KI) of 7.5 nM and afforded a very good selectivity over hCA I. Compound 32 was the most potent inhibitor against hCA IX (KI = 6.3 nM), 4-fold stronger than the drug acetazolamide AAZ (KI = 25 nM), used herein as a reference compound, and showed remarkable selectivity over hCA I and II. The coumarin-biotin derivatives 37-39 showed outstanding selectivity towards on-target enzymes (hCA IX and XII) and appear as plausible leads for designing of CAIs.

Phosphorylation strongly affects the inhibition of human carbonic anhydrase I CO2 hydration activity

Human carbonic anhydrases (hCAs) have essential roles in respiration, acid-base balance, and fluid secretion, with implications in diseases such as glaucoma, epilepsy, obesity, and cancer. Of the fifteen known hCAs, human CA I (hCA I) is particularly abundant in erythrocytes, playing a critical role in CO2 transport. Despite extensive research on hCA I, the impact of post-translational modifications (PTMs), particularly phosphorylation, on its catalytic activity and inhibitor binding remains poorly understood. Although multiple phosphorylation sites have been identified in hCA I in vivo through high-throughput proteomics studies including at the highly conserved Ser51 residue, the functional consequences of these modifications are not well characterized. We investigated the effects of a phosphomimetic mutation at Ser51 on hCA I, examining its catalytic efficiency and susceptibility to inhibition by sulfonamides and anions. Using a recombinant expression system and a stopped-flow kinetic assay, we characterized the CO2 hydration activity and inhibition profiles of S51E hCA I compared to the wild type enzyme. Our results demonstrate that the S51E mutation increases the catalytic turnover rate (kcat) from 2.0 × 105 s−1 to 2.6 × 105 s−1 but significantly decreases substrate affinity, raising the Michaelis constant (KM) from 4.0 mM to 13.9 mM, reducing overall catalytic efficiency by over 50 %. Inhibition studies with a panel of 41 sulfonamides revealed that the S51E mutation dramatically alters inhibitor sensitivity, particularly for the most effective inhibitors. For example, 15 of the 16 most effective sulfonamide inhibitors for hCA I (with KIs <350 nM) were an average of over 35-fold less effective in inhibiting S51E hCA I than the wild type. The KI of the anticonvulsant zonisamide increased from 31 nM for the wild type hCA I to 4.0 μM. The inhibition profile with a panel of 37 small anions further indicated that the S51E mutant exhibited significantly reduced susceptibility to inhibition by 24 out of 37 tested anions, with some KI values increasing by up to 11,000-fold for inhibitors like hydrogen sulfide. This study underscores the significant impact that phosphorylation may have on hCA I function and inhibition. By characterizing the effects of phosphorylation on the CO2 hydration activity and inhibitor sensitivity of hCA I, these findings represent early steps in developing more selective proteoform-specific inhibitors, which could lead to more effective treatments for diseases involving carbonic anhydrases.

Interactions of novel 1,3-diaryltriazene-sulfamethazines with carbonic anhydrases: Kinetic studies and in silico simulations

Sulfonamides, recognized as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, are crucial in treating diverse diseases, including epilepsy, glaucoma, bacterial infections, and various pathological processes, e.g., high blood pressure, rheumatoid arthritis, ulcerative colitis, pain, and inflammation. Additionally, therapeutically, 1,3-diaryl-substituted triazenes and sulphamethazines (SM) are integral components in various drug structures, and the synthesis of novel compounds within these two categories holds substantial significance. Herein, ten 1,3-diaryltriazene-substituted sulphamethazine derivatives SM(1-10), which were created by reacting the diazonium salt of sulphamethazine with substituted aromatic amines, were synthesized and the physiologically and pharmacologically relevant human (h) isoforms hCA I and II, cytosolic isozymes, were included in the study. The synthesized compounds showed excellent inhibition versus hCAs; the 4-butoxy (SM7, KI of 5.69 ± 0.59 nM) compound exhibited a potent inhibitory effect against the hCA I compared with the reference drug acetazolamide (AAZ, KI of 116.00 ± 8.48 nM). The 4-cyano (SM4, KI of 5.87 ± 0.57 nM) compound displayed higher potency than AAZ (KI of 57.25 ± 4.15 nM) towards hCA II. Meanwhile, among the synthesized molecules, the 3,4-dimethoxy (SM9, KI of 74.98 ± 10.49 nM, SI of 9.94) compound (over hCA I) displayed a noticeable selectivity for hCA isoform II. The target compounds in the molecular docking investigation were determined to take part in various hydrophilic and hydrophobic interactions with nearby amino acids and fit nicely into the active sites of the hCAs. This research has yielded compounds displaying varying affinity toward hCA isoenzymes, ultimately serving as potent and selective hCA inhibitors. Given its substantial biological inhibitory potency, this particular derivative series is determined to hold the potential to serve as a promising lead compound against these hCAs.

The effectiveness of transferring patients with open-angle glaucoma to therapy with a preservative-free fixed combination of a carbonic anhydrase inhibitor and a prostaglandin analogue

The effectiveness of transferring patients with open-angle glaucoma to therapy with a preservative-free fixed combination of a carbonic anhydrase inhibitor and a prostaglandin analogue

Novel thiazolotriazole and triazolothiadiazine scaffolds as selective tumor associated carbonic anhydrase inhibitors endowed with cathepsin B inhibition.

The present research focused on the tail-approach synthesis of novel extended thiazolotriazoles (8a-8j) and triazolothiadiazines (11a-11j) including aminotriazole intermediate 10. After successful synthesis, all the compounds were evaluated for their inhibition potential against cytosolic isoforms of human carbonic anhydrase (hCA I, II), tumor-linked transmembrane isoforms (hCA IX, XII), and cathepsin B. As per the inhibition data, the newly synthesized compounds showed poor inhibition against hCA I. Many of the compounds showed effective inhibition toward hCA IX and/or XII in low nanomolar concentration. Despite the strong to moderate inhibition of hCA II by these compounds, more than half of them demonstrated better inhibition against hCA IX and/or XII, comparatively. Further, insights of CA inhibition data of these extended analogs and their comparison with earlier reported thiazolotriazole and triazolothiadiazine derivatives might help in the rational design of novel potent and selective hCA IX and XII inhibitors. The novel compounds were also found to possess anti-cathepsin B potential at a low concentration of 10-7 M. Broadly, compounds of series 11a-11j presented more effective inhibition against cathepsin B than their counterparts in series 8a-8j. Moreover, these in vitro results with respect to cathepsin B inhibition were also supported by the in silico insights obtained via molecular modeling studies.

Computational Analysis and Inhibition Study of Carbonic Anhydrase from Azadirachta indica Leaves

Introduction: Carbonic anhydrase (CA) has been an enzyme of great interest for its application in carbon dioxide sequestration. A total of 66 protein sequences of plant CAs were computationally analyzed and submitted to bioinformatics for motif and domain identification, multiple sequence alignment, and phylogenetic analysis. Method: The current work aims to extend knowledge among researchers in better understanding the structure of AZDI CA by analyzing its physicochemical properties, secondary structure prediction, 3D modeling of protein sequence, and its validation using a variety of conventional computational methods. Results: The accuracy of the predicted 3D structure checked by the Ramachandran plot generated by PROCHECK showed that for the CA protein sequence 93.1%, was observed in the most favored regions, VERIFY 3D 69.44% and ERRAT 98.09%. AZDI CA was docked with various anions and sulphonamide derivatives to study their inhibitory effect and calculate binding energy by using Autodock 4.2. Ethoxzolamide is found to be a better inhibitor of AZDI CA with binding energy -8.71 kCal/mol and KI value 0.0004 mM. Further MD simulation of the docked complex of ethoxzolamide with AZDI CA was done using SCHRODINGER DESMOND software. Conclusion: The outcomes of this research will have a significant influence on biochemistry, biotechnology, and potential applications of AZDI CA and similar plant CAs in determining potent inhibitors for drug targets in treating various diseases.

Lasamide, a Potent Human Carbonic Anhydrase Inhibitor from the Market: Inhibition Profiling and Crystallographic Studies.

Lasamide is a synthetic precursor and a contaminant of the diuretic Furosemide manufacturing process and represents a highly valuable building block for fragment-based drug discovery approaches. We assessed the ability of Lasamide to inhibit in vitro the human-expressed Carbonic Anhydrases by means of the stopped-flow technique, and we assessed its binding modes within hCAs II and XII-mimic catalytic clefts by X-ray crystallography. Interestingly, an unprecedented crystal form for the hCA IX mimic H-tag is reported and discussed herein.

Multi- and poly-pharmacology of carbonic anhydrase inhibitors.

Eight genetically distinct families of the enzyme carbonic anhydrase (CA, EC 4.2.1.1) were described in organisms allover the phylogenetic tree. They catalyze the hydration of CO2 to bicarbonate and protons, and are involved in pH regulation, chemosensing and metabolism. The 15 α-CA isoforms present in humans are pharmacological drug targets known for decades, their inhibitors being used as diuretics, antiglaucoma, antiepileptic or antiobesity drugs, as well as for the management of acute mountain sickness, idiopathic intracranial hypertension and recently, as antitumor theragnostic agents. Other potential applications include the use of CA inhibitors (CAIs) in inflammatory conditions, cerebral ischemia, neuropathic pain, or for Alzheimer's/Parkinson's disease management. CAs from pathogenic bacteria, fungi, protozoans and nematodes started to be considered as drug targets in recent years, with notable advances registered ultimately. CAIs have a complex multipharmacology probably unique to this enzyme, which has been exploited intensely but may lead to other relevant applications in the future, due to the emergence of drug design approaches which afforded highly isoform-selective compounds for most α-CAs known to date. They belong to a multitude of chemical classes (sulfonamides and isosteres, (iso)coumarins and related compounds, mono- and dithiocarbamates, selenols, ninhydrines, boronic acids, benzoxaboroles, etc). The polypharmacology of CAIs will also be discussed since drugs originally discovered for the treatment of non-CA related conditions (topiramate, zonisamide, celecoxib, pazopanib, thiazide and high-ceiling diuretics) show efective inhibition against many CAs, which led to their repurposing for diverse pharmacological applications. Significance Statement Carbonic anhydrase inhibitors have multiple pharmacologic applications as diuretics, antiglaucoma, antiepileptic, antiobesity, anti-acute mountain sickness, anti-idiopathic intracranial hypertension and as antitumor drugs. Their use in inflammatory conditions, cerebral ischemia, neuropathic pain, or neurodegenerations started to be investigated recently. Parasite carbonic anhydrases are also drug targets for antiinfectives with novel mechanisms of action which can by pass drug resistance to commonly used such agents. Drugs discovered for the management of other conditions that effectively inhibit these enzymes exert interesting polypharmacologic effects.

Near Add Power of Glaucoma Patients with Early Presbyopia.

Purpose: Glaucoma medication may accelerate the progression of presbyopia. The aim of this study was to compare presbyopia between controls and patients with glaucoma in their 40s. Methods: This was a cross-sectional study of bilateral phakic participants aged between 40 and 49, which included controls (n = 114, mean age 46.1 ± 2.7 y) and patients with primary open-angle glaucoma (n = 105, 46.4 ± 2.7 y) who had been using FP receptor agonists, beta blockers, and carbonic anhydrase inhibitors for at least six months. We compared the near add power between the two groups. Results: The mean near add power and the prevalence of symptomatic presbyopia (near add power ≥ 1.50 D) were 1.16 ± 0.74 D and 42.1% for controls and 1.77 ± 0.71 D (p < 0.01) and 79.0% (p < 0.01) for glaucoma patients, respectively. The odds ratio (OR) and confidence interval for symptomatic presbyopia were associated with age (1.36, 1.21-1.52), ganglion cell complex thickness (0.96, 0.94-0.99), presence of glaucoma (6.19, 3.13-12.23), and number of glaucoma medications (4.26, 2.42-7.43). Among medications, only FP receptor agonists (5.79, 2.68-12.32) produced significant results. Survival analysis showed that glaucoma patients reached the threshold of a near add power of +1.50 D significantly sooner than controls (p < 0.05; log-rank test). Conclusions: Glaucoma patients, especially those using FP receptor agonists, had higher near add power than controls.

Privileged Scaffold Hybridization in the Design of Carbonic Anhydrase Inhibitors.

Human Carbonic Anhydrases (hCA) are enzymes that contribute to cancer's development and progression. Isoforms IX and XII have been identified as potential anticancer targets, and, more specifically, hCA IX is overexpressed in hypoxic tumor cells, where it plays an important role in reprogramming the metabolism. With the aim to find new inhibitors towards IX and XII isoforms, the hybridization of the privileged scaffolds isatin, dihydrothiazole, and benzenesulfonamide was investigated in order to explore how it may affect the activity and selectivity of the hCA isoforms. In this respect, a series of isatin thiazolidinone hybrids have been designed and synthesized and their biological activity and selectivity on hCA I, hCA II, hCA IX, and hCA XII explored. The new compounds exhibited promising inhibitory activity results on isoforms IX and XII in the nanomolar range, which has highlighted the importance of substituents in the isatin ring and in position 3 and 5 of thiazolidinone. In particular, compound 5g was the most active toward hCA IX, while 5f was the most potent inhibitor of hCA XII within the series. When both potency and selectivity were considered, compound 5f appeared as one of the most promising. Additionally, our investigations were supported by molecular docking experiments, which have highlighted the putative binding poses of the most promising compound.

Hydrogen Sulfide-Releasing Carbonic Anhydrase Inhibitors Effectively Suppress Cancer Cell Growth.

This study proposes a novel therapeutic strategy for cancer management by combining the antitumor effects of hydrogen sulfide (H2S) and inhibition of carbonic anhydrases (CAs; EC 4.2.1.1), specifically isoforms IV, IX, and XII. H2S has demonstrated cytotoxicity against various cancers at high concentrations. The inhibition of tumor-associated CAs leads to lethal intracellular alkalinization and acidification of the extracellular tumor microenvironment and restores tumor responsiveness to the immune system, chemotherapy, and radiotherapy. The study proposes H2S donor-CA inhibitor (CAI) hybrids for tumor management. These compounds effectively inhibit the target CAs, release H2S consistently, and exhibit potent antitumor effects against MDA-MB-231, HCT-116, and A549 cancer cell lines. Notably, some compounds display high cytotoxicity across all investigated cell lines. Derivative 30 shows a 2-fold increase in cytotoxicity (0.93 ± 0.02 µM) under chemically induced hypoxia in HCT-116 cells. These compounds also disturb the cell cycle, leading to a reduction in cell populations in G0/G1 and S phases, with a notable increase in G2/M and Sub-G1. This disruption is correlated with induced apoptosis, with fold increases of 37.2, 24.5, and 32.9 against HCT-116 cells and 14.2, 13.1, and 19.9 against A549 cells compared to untreated cells. These findings suggest the potential of H2S releaser-CAI hybrids as effective and versatile tools in cancer treatment.

Adverse Events and Efficacy of Acetazolamide in Meniere's Disease in a Vertigo Outpatient Clinic: A Retrospective Study.

Background Acetazolamide, a carbonic anhydrase inhibitor, is used in the treatment of several otolaryngological conditions, including Meniere's disease (MD). Despite its efficacy in reducing vertigo attacks, it is associated with a high rate of adverse events such as sensory disturbances, electrolyte imbalances, and liver dysfunction. The primary objective of this study is to evaluate the efficacy of acetazolamide in reducing vertigo attacks in MD patients. The secondary objective is to determine the incidence and severity of adverse drug events associated with acetazolamide treatment in this patient population. Methodology The study subjects were 70 patients who visited the vertigo outpatient clinic of our department from March 2019 to July 2024 and were diagnosed with definite or probable MD. Results A total of 15 cases had a history of acetazolamide prescription, with doses ranging from 125 to 750 mg/day. In total, 12 (80%) patients had symptoms of numbness in hands, feet, or other parts of the body, which caused discontinuation of medication after the initial prescription in five cases. Hypokalemia with liver dysfunction and hypokalemia with an open fracture of the distal end of the right radius due to staggering were observed in one patient each. In both cases of hypokalemia, Chinese herbal medicines containing licorice were prescribed in combination. Overall, 11 (73%) cases had a decrease in vertigo attacks. Hearing thresholds did not recover significantly after the prescription. Conclusions Although acetazolamide is effective in preventing vertigo attacks of MD, the rate of adverse events is high. Detailed instructions, careful dosage adjustment, periodic assessment of symptoms, and blood examinations for electrolyte and liver function are required.

Structure based exploration of mitochondrial alpha carbonic anhydrase inhibitors as potential leads for anti-obesity drug development.

Obesity has emerged as a major health challenge globally in the last two decades. Dysregulated fatty acid metabolism and de novo lipogenesis are prime causes for obesity development which ultimately trigger other co-morbid pathological conditions thereby risking life longevity. Fatty acid metabolism and de novo lipogenesis involve several biochemical steps both in cytosol and mitochondria. Reportedly, the high catalytically active mitochondrial carbonic anhydrases (CAVA/CAVB) regulate the intercellular depot of bicarbonate ions and catalyze the rapid carboxylation of pyruvate and acetyl-co-A to acetyl-co-A and malonate respectively, which are the precursors of fatty acid synthesis and lipogenesis. Several in vitro and in vivo investigations indicate inhibition of mitochondrial carbonic anhydrase isoforms interfere in the functioning of pyruvate, fatty acid and succinate pathways. Targeting of mitochondrial carbonic anhydrase isoforms (CAVA/CAVB) could thereby modulate gluconeogenetic as well as lipogenetic pathways and pave way for designing of novel leads in the development pipeline of anti-obesity medications. The present review unveils a diverse chemical space including synthetic sulphonamides, sulphamates, sulfamides and many natural bioactive molecules which selectively inhibit the mitochondrial isoform CAVA/CAVB with an emphasis on major state-of-art drug design strategies. More than 60% similarity in the structural framework of the carbonic anhydrase isoforms has converged the drug design methods towards the development of isoform selective chemotypes. While the benzene sulphonamide derivatives selectively inhibit CAVA/CAVB in low nanomolar ranges depending on the substitutions on the phenyl ring, the sulpamates and sulpamides potently inhibit CAVB. The virtual screening and drug repurposing methods have also explored many non-sulphonamide chemical scaffolds which can potently inhibit CAVA. The review could pave way for the development of novel and effective anti-obesity drugs which can modulate the energy metabolism.

Harnessing Nitric Oxide-Donating Benzofuroxans for Targeted Inhibition of Carbonic Anhydrase IX in Cancer.

We describe here the design and antitumor evaluation of benzofuroxan-based nitric oxide (NO)-donor hybrid derivatives targeting human carbonic anhydrases (hCAs) IX and XII. The most effective compounds, 27 and 28, demonstrated potent dual action, exhibiting low nanomolar inhibition constants against hCA IX and significant NO release. Notably, compound 27 showed significant antiproliferative effects against various cancer cell lines, particularly renal carcinoma A-498 cells. In these cells, it significantly reduced the expression of CA IX and iron-regulatory proteins, inducing apoptosis via mitochondrial caspase activity and ferroptosis pathways, as evidenced by increases in ROS, nitrite, and down-regulated expression of ferritin-encoding genes. In three-dimensional tumor models, compound 27 effectively reduced spheroid size and viability. In vivo toxicity studies in mice indicated that the compounds were well-tolerated, with no significant alterations in kidney function. These findings underscore the potential of benzofuroxan-based CA inhibitors for further preclinical evaluations as therapeutic agents targeting renal cell carcinoma.

Enzyme Inhibitors as Multifaceted Tools in Medicine and Agriculture.

Enzymes are molecules that play a crucial role in maintaining homeostasis and balance in all living organisms by catalyzing metabolic and cellular processes. If an enzyme's mechanism of action is inhibited, the progression of certain diseases can be slowed or halted, making enzymes a key therapeutic target. Therefore, identifying or developing enzyme inhibitors is essential for treating significant diseases and ensuring plant defense against pathogens. This review aims to compile information on various types of enzyme inhibitors, particularly those that are well studied and beneficial in both human and plant contexts, by analyzing their mechanisms of action and the resulting benefits. Specifically, this review focuses on three different types of enzyme inhibitors that are most studied, recognized, and cited, each with distinct areas of action and potential benefits. For instance, serine enzyme inhibitors in plants help defend against pathogens, while the other two classes-alpha-glucosidase inhibitors and carbonic anhydrase inhibitors-have significant effects on human health. Furthermore, this review is also intended to assist other researchers by providing valuable insights into the biological effects of specific natural or synthetic inhibitors. Based on the current understanding of these enzyme inhibitors, which are among the most extensively studied in the scientific community, future research could explore their use in additional applications or the development of synthetic inhibitors derived from natural ones. Such inhibitors could aid in defending against pathogenic organisms, preventing the onset of diseases in humans, or even slowing the growth of certain pathogenic microorganisms. Notably, carbonic anhydrase inhibitors have shown promising results in potentially replacing antibiotics, thereby addressing the growing issue of antibiotic resistance.

Unraveling the mechanism of carbonic anhydrase IX inhibition by alkaloids from Ruta chalepensis: A synergistic analysis of in vitro and in silico data

Due to the pivotal role of carbonic anhydrase IX (CA IX) in pathological conditions, there's a pressing need for novel inhibitors to improve patient outcomes and clinical management. Herein, we investigated the inhibitory efficacy of six alkaloids from Ruta chalepensis against CA IX through in vitro inhibition assay and computational modeling. Skimmianine and maculosidine displayed significant inhibitory activity in vitro, with low IC50 values of 105.2 ± 3.2 and 295.7 ± 14.1 nM, respectively. Enzyme kinetics analyses revealed that skimmianine exhibited a mixed inhibition mode, contrasting with the noncompetitive inhibition mechanism observed for the reference drug (acetazolamide), as indicated by intersecting lines in the Lineweaver-Burk plots. The findings of docking calculations revealed that skimmianine and maculosidine exhibited extensive polar interactions with the enzyme. These alkaloids demonstrate substantial binding interactions and occupy identical binding site as acetazolamide, thereby enhancing their efficacy as inhibitors of CA IX. Utilizing a 100 ns molecular dynamics (MD) simulation, the dynamic interactions between isolated alkaloids and CA IX were intensively assessed. Analysis of diverse MD parameters revealed that skimmianine and maculosidine displayed consistent trajectories and notable energy stabilization during their interaction with CA IX. The findings of MM/PBSA analysis depicted the minimum binding free energy for skimmianine and maculosidine. In addition, the Potential Energy Landscape (PEL) analysis revealed distinct and stable conformational states for the CA IX-ligand complexes, with Skimmianine showing the most stable and lowest energy configuration. These computational findings align with experimental results, emphasizing the potential efficacy of skimmianine and maculosidine as inhibitors of CA IX.

Preparation and characterization of chitosan nanoparticles with extracts of Rheum ribes, evaluation of biological activities of extracts and extract loaded nanoparticles

The biological activities of different parts of the Rheum ribes plant were evaluated comparatively. Extracts showing strong biological activity were identified and it was determined which of the extract-loaded nanoparticles showed stronger activity. Cytotoxic activity of R. ribes extracts was calculated on glial (C6) and fibroblast (NIH 3T3) cells using XTT assay. Spectrophotometry was used to evaluate the impact of these compounds on the enzyme activities of human carbonic anhydrase I and II (hCA I and hCA II). The findings showed that chitosan NPs with extracts loaded on them have a lower IC50 value and more cytotoxic activity in C6 cells than chitosan NPs with only extracts. R. ribes young shoots ultrasonic methanol extract (RYU) was shown to have the strongest antiproliferative efficacy against C6 cells. Results showed that RYU and ultrasonic methanol extract of R. ribes radix (RRU) were determined as the best carbonic anhydrase inhibitors. According to results of particle size, encapsulation efficiency, and release studies of chitosan NPs, it has been observed that they are suitable for application. At a concentration of 10 µg/mL, it was found that none of the R. ribes extracts exhibited cytotoxic action toward the NIH 3T3 cell line. According to results of particle size, encapsulation efficiency, and release studies of chitosan NPs, it has been observed that they are suitable for application. It was observed that none of the extracts of R. ribes at a concentration of 10 µg/mL showed cytotoxic activity in the NIH 3T3 cell line.

Phytochemical profiles, bioactivities, and molecular docking and molecular dynamics approaches of endemic Campanula baskilensis Behçet (campanulaceae)

Campanula species have phenolic derivatives with a broad biological potential. This study aimed to investigate the chemical contents, bioactivities, and prediction of the biological effect mechanism using the molecular docking study for C. baskilensis (CB) leaf (L), root (R), and stem (S) extracts.CBL gave the highest phenolic contents as hesperidin at 7.56 mg/g extract. Total phenolic and flavonoid contents of CBS were determined as 3.12 ± 0.05 mg GAE/g and 1.11 ± 0.11 mg QE/g, respectively. CBS and CBL exhibited high DPPH• scavenging, H2O2 scavenging, AChE, BChE, carbonic anhydrase, lipase, and tyrosinase inhibition effects and demonstrated potent antimicrobial activity. The strong phenolic components of CBS and CBL extracts contributed to their biological activities. According to the molecular docking results, a high inhibition effect was observed on the inhibition activities due to the presence of hesperidin, which is the highest main component of the extracts. Additionally, docking studies were performed on hesperidin for the first time. Dynamics study showed that the interaction between the hesperidin and BChE increased stability, producing a stable complex form within 100 ns. In conclusion, C. baskilensis extracts, especially hesperidin, may be promising potential sources for neurological diseases and complementary medicine.

Light‐Induced Unlocking Reactivity of Fragments for Fast Target‐Guided Synthesis of Carbonic Anhydrase Inhibitors

AbstractWe showcase the successful combination of photochemistry and kinetic target‐guided synthesis (KTGS) for rapidly pinpointing enzyme inhibitors. KTGS is a fragment‐based drug discovery (FBDD) methodology in which the biological target (BT) orchestrates the construction of its own ligand from fragments featuring complementary reactive functionalities. Notably, fragments interacting with the protein binding sites leverage their spatial proximity, facilitating a preferential reaction. Consequently, the resulting bivalent ligand exhibits heightened affinity. Within the realm of KTGS strategies, in situ click chemistry stands out as the most widely used to identify potent protein binders. This approach requires significant protein contributions, such as binding interactions and appropriate orientations of fragments, to overcome high activation barriers. This leads to prolonged incubation times and the potential for generating false negatives, thereby limiting this strategy to proteins that are stable enough in buffer. We herein unveil the possibility to integrate photochemistry into the realm of KTGS, accelerating the ligation reaction between fragments to a time scale of minutes. This approach should significantly expand the narrow reactivity window of traditional KTGS reactions, paving the way for the exploration and development of novel photo‐KTGS reactions.