Derivatives 4e Research Articles

Preparation and Transformations of Acetophenone-Derived Enamino Ketones, BF2-β-Ketoiminates, and BF2-β-Diketonates

A series of differently substituted β-enaminones 2a,b, 4a–i, 8a–d, and 9–13, their BF2-β-ketoiminate complexes 5a–d, and BF2-β-diketonate complexes 6a–d were prepared as model substrates for photochemical transformations. The attempted photochemical transformations of enaminones 2, 4, 8 and BF2-β-ketoiminate complexes 5 failed. On the other hand, irradiation of mixtures of BF2-β-diketonate complexes 6a–d and cycloalkanes with UV-A light (365 nm) gave the corresponding De Mayo reaction products 7a–f in 9–30% yields. The photochemical ring-expansion of acetyl tetralone-derived BF2-complex 6d gave novel diannulated cyclooctane derivatives 7e and 7f, which would be difficult to obtain using conventional cyclization methods.

Synthesis and Anticancer Activity Evaluation of N-(3,4,5- Trimethoxycinnamoyl)anthranilic Acid Derivatives

There is an urgent need to search for more efficient, better-tolerated anticancer drugs. Tranilast, a synthetic analog of tryptophan metabolite, has been shown to inhibit the growth of various cancer cells. In our previous study, the tranilast analog TRA01 [N-(3,4,5- trimethoxycinnamoyl)anthranilic acid] was identified as a promising agent against the proliferation of MCF-7 and HepG2 cell lines along with good binding affinity on the transforming growth factor beta 1 (TGFβ1) target. To further explore the structure-activity relationship, a series of N-(3,4,5- trimethoxycinnamoyl)anthranilic acid derivatives (5a–i) were successfully synthesized via a two-step synthetic procedure based on N-acylation and Knoevenagel-Doebner reactions and their structures were determined using 1 H-NMR, 13C-NMR, and MS spectra. The derivatives (5a–i) were evaluated for in vitro activity using MTT assay and in silico docking on TGFβ1 target by AutoDockTools–1.5.6 software. The bioactivity results of 5a–i showed 12.30–27.04% and 19.13–46.23% inhibition on proliferation of MCF-7 and HepG2 cell lines at 100 µM concentration, respectively, with the fluorinated derivatives (5a and 5e) possessing the strongest inhibitory activities. The molecular docking also found the best binding affinity of 5a (-8.70 Kcal/mol) and 5e (-8.71 Kcal/mol) on the TGFβ1 target. The SAR result revealed that substituents on the benzene ring of anthranilic acid were not favored for anticancer activity. Although these derivatives exhibited weak anticancer properties, the good binding affinity to the TGFβ1 target suggested certain potential of this scaffold for further study on this target.

DACH-Based Chiral Sensing Platforms as Tunable Benzamide-Chiral Solvating Agents for NMR Enantioselective Discrimination.

Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure trans-1,2-diaminocyclohexane (trans-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives 6a-6n have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in 1H NMR analysis. The highly efficient chiral recognition of CSA 6e on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via 1H, 19F, and 31P NMR spectroscopy. The quality of enantiodiscrimination was evaluated by means of the enantioresolution parameter Rs. Single-crystal X-ray analysis of three derivatives 6c, 6e, and 6h helped to understand enantiomeric recognition for the promising NMR analysis. Interestingly, the NMR signals of nonequivalent protons between the R and S configurations were completely opposite in the presence of CSA 6e and its stereoisomer, which can be utilized to establish a straightforward method for the configuration assignment of diverse hydroxy acid substrates.

Triadenosides A-F, benzophenone rhamnosides from Triadenum japonicum and their anti-ferroptosis activity.

Previously undescribed benzophenone rhamnosides, triadenosides A-F (1-6), were isolated from the aerial parts of Triadenum japonicum (Blume) Makino (Hypericaceae), where known compounds including benzophenone rhamnosides (7 and 8), benzophenone C-glucoside (9), flavonols and their glycosides (10-17), and biflavone (18) were also isolated and identified. Detailed spectroscopic analysis revealed that triadenoside A (1) was 2,3',5'-trihydroxy-4,6-dimethoxybenzophenone 2-O-α-L-rhamnopyranoside, while the absolute configuration of the rhamnosyl moiety was confirmed by HPLC analysis. Triadenosides B-E (2-5) were assigned as acetyl derivatives of 1 in their rhamnosyl moieties. In contrast, triadenoside F (6) was elucidated to be 2,3',5',6-tetrahydroxy-4-methoxybenzophenone 2-O-α-L-(4″-O-acetyl)rhamnopyranoside. Compounds 1-18 isolated from T. japonicum as well as some benzophenone derivatives (5a-5e, 6a, and 8a) prepared from 5, 6, and 8 were evaluated for their inhibitory activity against RSL3-induced ferroptosis on human hepatoma Hep3B cells, showing significant inhibitory effects of triadenosides A-E (1-5) and their derivatives (5c, 5d, and 5e) with EC50 values ranging from 18.0 to 41.4nM comparable to that of a ferroptosis inhibitor, ferrostatin-1, whereas triadenoside F (6) did not exhibit such activity.

Synthesis and biological evaluation of novel D-ring fused steroidal N(2)-substituted-1,2,3-triazoles.

In this study, a series of 13 new D-ring fused steroidal N(2)-substituted-1,2,3-triazoles were synthesized, characterized and evaluated for their biological activities. The relative binding affinities of the synthesized compounds for the ligand-binding domains of estrogen receptors α and β, androgen receptor and glucocorticoid receptor demonstrated that androstane derivatives 3a and 3h and estratriene derivative 4e showed highly specific and strong binding affinity for estrogen receptor β, while 3b, 3e, 4a and 4b displayed high binding affinity for the glucocorticoid receptor. The synthesized compounds were tested for their ability to inhibit aldo-keto reductases 1C3 and 1C4 in vitro by monitoring NADPH consumption using fluorescence spectroscopy. The most potent aldo-keto reductase 1C3 inhibitors were compounds 3h (71.17%) and 3f (69.9%). Moreover, a molecular docking study was carried out for compounds 3f and 3h against aldo-keto reductase 1C3 and results showed that compounds 3h and 3f could bind in the same site and orientation as EM1404. However, polar atoms in the triazole group enable additional hydrogen bonding deeper in SP1 with Tyr319, Tyr216 and the NADP+ cofactor, which are not visible in the AKR1C3-EM1404 crystal structure. The synthesized compounds were screened for their anticancer activity against four cancer cell lines. Compound 3f demonstrated moderate toxic effects across various cancer types, while displaying lower toxicity towards the healthy cell line. In summary, our findings indicate that N(2)-substituted-1,2,3-triazoles are high-affinity ligands for estrogen receptor β and glucocorticoid receptor, inhibitors of aldo-keto reductase 1C3 enzyme, and exhibit antiproliferative effects against cancer cells, suggesting that they could serve as scaffolds for anticancer drug development.

Design, synthesis, and structure-activity relationship studies of 6H-benzo[b]indeno[1,2-d]thiophen-6-one derivatives as DYRK1A/CLK1/CLK4/haspin inhibitors.

A series of sulfur-containing tetracycles was designed and evaluated for their ability to inhibit protein kinase DYRK1A, a target known to have several potential therapeutic applications including cancers, Down syndrome or Alzheimer's disease. Our medicinal chemistry strategy relied on the design of new compounds using ring contraction/isosteric replacement and constrained analogy of known DYRK1A inhibitors, thus resulting in their DYRK1A inhibitory activity enhancement. Whereas a good inhibitory effect of targeted DYRK1A protein was observed for 5-hydroxy compounds 4i-k (IC50 = 35-116 nM) and the 5-methoxy derivative 4e (IC50 = 52 nM), a fairly good selectivity towards its known DYRK1B off-target was observed for 4k. In addition, the most active compound 4k, having an ATP-competitive mechanism of action, proved to be also a potent inhibitor of CLK1/CLK4 (IC50 = 20 and 26 nM) and, to a lesser extent, of haspin (IC50 = 76 nM) kinases. In silico docking studies within the DYRK1A, CLK1/CLK4 and haspin ATP binding sites were carried out to understand the interactions of our tetracyclic derivatives 4 with these targets. Antiproliferative activities on U87/U373 glioblastoma cell lines of the most potent compound 4k showed a moderate effect (IC50 values between 33 and 46 μM). Microsomal stabilities of the designed compounds 4a-m were also investigated, showing great disparities, depending on benzo[b]thiophene ring 5-substitution.

Phthalazine Derivatives as VEGFR‐2 Inhibitors: Docking, ADMET, Synthesis, Design, Anticancer Evaluations, and Apoptosis Inducers

ABSTRACTNew phthalazine‐derived inhibitors for VEGFR‐2 were synthesized for anticancer evaluations. Also, docking studies were performed to explore the suggested binding orientations of the novel derivatives inside the binding site of VEGFR‐2. The achieved biological data were extremely interrelated to that of docking study. In specific, derivative 3f was the greatest effective compound against HepG2 and MCF‐7 cancer cell lines with IC50 = 0.17 ± 0.01 and 0.08 ± 0.01 µM individually. The six highly active derivatives 3b, 3e, 3f, 3g, 6a, and 6b were estimated for their VEGFR‐2 inhibitory effects. Derivative 3f was the greatest effective compound which inhibited VEGFR‐2 at IC50 = 0.0557 ± 0.002 µM. The activities of 3f were assessed against MCF‐7 cancer cells for apoptosis induction, cell cycle distribution, and growth inhibition. Compound 3f induced early apoptosis (21.44%) by more than 36 folds over the control (0.59%). The obtained results showed that compound 3f induced necrotic effect (6.03%) by more than threefolds over the control (1.75%). On the other hand, compound 3f improved the level of the pro‐apoptotic protein; Bax by approximately fivefolds. Moreover, compound 3f noticeably decreased the levels of the anti‐apoptotic proteins Bcl‐2 by nearly fourfolds in comparison to the control. In addition, derivative 3f remarkably enhanced the Bax/Bcl2 ratio by nearly 18 folds, as compared to the control. Finally, our derivatives 3f, 3g, and 6b revealed good in silico considered ADMET profile in comparing to sorafenib.

Novel 4-alkoxy Meriolin Congeners Potently Induce Apoptosis in Leukemia and Lymphoma Cells.

Meriolins (3-(pyrimidin-4-yl)-7-azaindoles) are synthetic hybrids of the naturally occurring alkaloids variolin and meridianin and display a strong cytotoxic potential. We have recently shown that the novel derivative meriolin16 is highly cytotoxic in several lymphoma and leukemia cell lines as well as in primary patient-derived lymphoma and leukemia cells and predominantly targets cyclin-dependent kinases (CDKs). Here, we efficiently synthesized nine novel 2-aminopyridyl meriolin congeners (3a-3i), i.e., pyrimeriolins, using a one-pot Masuda borylation-Suzuki coupling (MBSC) sequence, with eight of them bearing lipophilic alkoxy substituents of varying length, to systematically determine the influence of the alkoxy sidechain length on the biological activity. All the synthesized derivatives displayed a pronounced cytotoxic potential, with six compounds showing IC50 values in the nanomolar range. Derivatives 3b-3f strongly induced apoptosis and activated caspases with rapid kinetics within 3-4 h in Jurkat leukemia and Ramos lymphoma cells. The induction of apoptosis by the most potent derivative 3e was mediated by the intrinsic mitochondrial death pathway, as it was blocked in caspase-9 deficient and Apaf-1 knockdown Jurkat cells. However, as recently shown for meriolin16, derivative 3e was able to induce apoptosis in the Jurkat cells overexpressing the antiapoptotic protein Bcl-2. Since tumor cells often inactivate the intrinsic mitochondrial apoptosis pathway (e.g., by overexpression of Bcl-2), these meriolin congeners represent promising therapeutic agents for overcoming therapeutic resistance.

Graphene Oxide Decorated SiO2/Fe3O4 as a Recyclable Catalyst for the Green Synthesis of Novel Thiazinoazepines via Multicomponent Reaction of Isatoic Anhydrides: Cytotoxic Activity and Theoretical Study

ABSTRACTThis work investigated the use of a complex technique including isatoic anhydrides, α‐haloketones, electron‐deficient acetylenic compounds, ammonium acetate, and isothiocyanates in a water‐based solution at normal room temperature in the presence of SiO2/Fe3O4@Graphene Oxide. The goal was to generate novel thiazinoazepine molecules with significant yields. The thiazinoazepines that have been synthesized contain NH functional groups with acidic protons and demonstrate notable antioxidant activity. The (3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐Diphenyltetrazolium Bromide), MTT assay was utilized to evaluate the cytotoxicity of all the synthesized compounds in vitro against cancer cell lines (MCF‐7 and A549) as well as normal cell lines). Cytotoxicity refers to the ability of a compound to kill cells. The derivative 6e was shown to be the most potent cytotoxic agent, similar to doxorubicin in its lack of selectivity. Alternatively, compound 6b might be considered as a compound that is equally effective but more selective than doxorubicin. Quantum chemical approaches utilizing density functional theory have been utilized to enhance comprehension of reaction mechanisms. The used technology for synthesizing thiazinoazepines provides several advantages, including rapid reaction kinetics, outstanding product yield, and straightforward product isolation.

Design, in silico studies and biological evaluation of novel chalcones tethered triazolo[3,4-a]isoquinoline as EGFR inhibitors targeting resistance in non-small cell lung cancer

A novel series of six [1,2,4]triazolo[3,4-a]isoquinolin-3-yl)-3-(1,3-diphenyl-1H-pyrazol-4-yl)prop-2-en-1-ones (3a–3f) was designed and synthesized. They were characterized based on spectral and elemental analyses. In silico studies were also committed to provide insights and a better understanding of their structural features. The six compounds were screened for their antiproliferative activity using the MTT assay against five human cancer cell lines, namely, A549, HCT116, PC3, HT29, and MCF-7 in parallel with the non-cancerous human lung cell line WI-38. The results showed that 3e and 3f have potential cytotoxic activities, especially on A549 cells with IC50 = 2.3 µM and 1.15 µM, respectively. Meanwhile, they recorded a minimal cytotoxic effect on WI-38 cells. Concerning the molecular mechanism of action, the present study showed the inhibitory effect of the six compounds against total EGFR. The most potent EGFR inhibitors were 3e and 3f with IC50 = 0.031 µM and 0.023 µM, respectively. The selectivity index of 3f for EGFRT790M was 1.81 times more selective than that of lapatinib. In addition, 3e and 3f initiated cell cycle arrest at the G2/M and pre-G1 phases along with the downregulation of anti-apoptotic protein Bcl2 and the upregulation of pro-apoptotic proteins: p53, Bax, and caspases 3, 8, and 9. Further studies are recommended to evaluate animal models’ promising anticancer activity and molecular mechanism of triazolo[3,4-a]isoquinoline derivatives 3e and 3f.

Synthesis of S-alkylated oxadiazole bearing imidazo[2,1-b]thiazole derivatives targeting breast cancer: In vitro cytotoxic evaluation and in vivo radioactive tracing studies

Breast cancer is the most common invasive cancer diagnosed in women, accounting for most cancer-related fatalities globally. Numerous investigations have revealed that breast cancer is characterized by abnormal expression and maintenance of EGFR levels. In terms of structural study and optimization of several EGFR inhibitors, two series of oxadiazole bearing imidazo[2,1-b]thiazole derivatives were designed and synthesized as potential EGFR inhibitors and assessed for their antitumor activity at NCI-USA. Four derivatives 3b, 3c, 3d and 3e elicited remarkable GI% against MDA-MB-468, T-47D and MCF-7 breast cancer cell lines. Thereafter, MTT assay was performed to reveal that compounds 3b (IC50 = 2.27 µM) and 3d (IC50 = 1.46 µM) showed promising cytotoxic activity against MCF-7 and MDA-MB-468 cell lines, respectively, compared to their reference drugs. Compounds 3b, 3d and 3e revealed good selectivity toward tumor cells with reasonable safety profile when tested against the normal cell line MCF-10a. In vitro EGFR inhibitory assay demonstrated that compounds 3b (IC50 = 0.099 µM) and 3d (IC50 = 0.086 µM) exhibited comparable inhibitory activity to the standard drug erlotinib (IC50 = 0.046 µM). A flow cytometric analysis demonstrated that derivatives 3b and 3d arrested the cell cycle at the S phase in MCF-7 and MDB-MB-468, respectively. Furthermore, the most active derivative 3d was subjected to in vivo radioactive studies. In-vivo biodistribution of 99mTc-3d complex showed a notable elevated accumulation in the targeted sarcoma muscle, indicating the targeting capacity of compound 3d in the tumor of sarcoma mice model. The binding mode of compounds 3b and 3d with EGFR was studied by molecular docking and was further inspected by molecular dynamic simulations. Both compounds were shown to be stable during the course of simulation and demonstrated a plausible interaction pattern with the EGFR binding pocket.

Synthesis and Molecular Docking Study of Hydrazone Schiff Bases of α‐Naphthalene‐Containing Alkyl Phenyl Ether Fragment as Potent α‐Amylase and α‐Glucosidase Inhibitors

AbstractIn this study, new Schiff base derivatives of α‐naphthalene acetic acid containing alkyl phenyl ether fragment have been effectively synthesized through multistep reaction process, characterized by 1H‐NMR and 13C‐NMR spectroscopy. These derivatives have been tested for their in vitro α‐amylase and α‐glucosidase inhibitory activities. In the series, 8 compounds (2j, 2f, 2e, 2m, 2a, 2b, 2l, and 2c) exhibited promising α‐amylase inhibition with IC50 values from 5.38 ± 0.36 to 14.59 ± 0.64 µg/mL. Similarly, in the case of α‐glucosidase inhibitory activity, 10 derivatives (2e, 2f, 2j, 2m, 2b, 2c, 2i, 2d, 2a, and 2l) exhibited excellent activity having IC50 values from 6.96 ± 0.39 to 16.27 ± 0.31 µg/mL, wheras the remaining derivatives exhibited good‐to‐least antidiabetic potential. The ADME properties were calculated for all Schiff base derivatives using Swiss‐ADME web tool. Furthermore, the docking studies identified the binding modes of the compounds.

Designing 1,2,3‐Triazole Derivatives for Targeted Inhibition of Proteolytic and Coagulant Activities in Bothrops Jararaca and Bothrops neuwiedi Snake Venoms

AbstractSnakebites inflict significant injuries on humans and animals, posing a severe global public health challenge due to high mortality and morbidity rates. This study presents results against the venoms of Bothrops jararaca and Bothrops neuwiedi using sixteen synthetic hybrid molecules containing thiophene and triazoles, designated as 6a–h and 7a–h. The compounds were assessed for their ability to inhibit proteolytic and plasma coagulant activities induced by the snake venoms, and their toxicity was analyzed. Most derivatives demonstrated nontoxicity through in silico analysis with the Osiris Property Explorer tool and in vitro cytotoxic hemocompatibility on red blood cells. Notably, only derivative 6e exhibited toxicity to erythrocytes, while 6b, 6d, 7c, and 7f displayed mutagenic, tumorigenic, or adverse effects on the reproductive system. Derivatives 6a, 6c–h, 7c–e, 7g, or 7h effectively inhibited the coagulating activity of B. jararaca venom, while 6a–b, 6d–e, 6h, or 7a–f inhibited coagulation induced by B. neuwiedi venom. All derivatives demonstrated inhibition of the proteolytic activity caused by B. jararaca venom, and derivatives 6a–d and 7e–f inhibited the activity of B. neuwiedi venom. Consequently, these derivatives exhibited varying degrees of efficacy in countering two crucial toxic effects of B. jararaca or B. neuwiedi venoms, suggesting their potential as antivenoms against both species.

Exploring the 3,5-Dibromo-4,6-dimethoxychalcones and Their Flavone Derivatives as Dual α-Glucosidase and α-Amylase Inhibitors with Antioxidant and Anticancer Potential.

The rising levels of type 2 diabetes mellitus (T2DM) and the poor medical effects of the commercially available antidiabetic drugs necessitate the development of potent analogs to treat this multifactorial metabolic disorder. It has been demonstrated that targeting two or more biochemical targets associated with the onset and progression of diabetes along with oxidative stress and/or cancer could be a significant strategy for treating complications related to this metabolic disorder. The 3,5-dibromo-4,6-dimethoxychalcones (2a-f) and the corresponding flavone derivatives (3a-f) were synthesized and characterized using spectroscopic (NMR, HR-MS and FT-IR) techniques. The inhibitory effect of both series of compounds against α-glucosidase and α-amylase was evaluated in vitro through enzymatic assays. Selected compounds were also evaluated for potential to activate or inhibit superoxide dismutase. Compound 3c was selected as a representative model for the flavone series and evaluated spectrophotometrically for potential to coordinate Cu(II) and/or Zn(II) ions implicated in the metal-catalyzed free radical generation. A plausible mechanism for metal-chelation of the test compounds is presented. Furthermore, the most active compounds from each series against the test carbohydrate-hydrolyzing enzymes were selected and evaluated for their antigrowth effect on the human breast (MCF-7) and lung (A549) cancer cell lines and for cytotoxicity against the African Green Monkey kidney (Vero) cell line. The parent chalcone 2a and flavone derivatives 3a, 3c and 3e exhibited relatively high inhibitory activity against the MCF-7 cells with IC50 values of 4.12 ± 0.55, 8.50 ± 0.82, 5.10 ± 0.61 and 6.96 ± 0.66 μM, respectively. The chalcones 2a and 2c exhibited significant cytotoxicity against the A549 cells with IC50 values of 7.40 ± 0.67 and 9.68 ± 0.80 μM, respectively. Only flavone 3c exhibited relatively strong and comparable cytotoxicity against the MCF-7 and A549 cell lines with IC50 values of 6.96 ± 0.66 and 6.42 ± 0.79 μM, respectively. Both series of compounds exhibited strong activity against the MCF-7 and A549 cell lines compared to the analogous quercetin (IC50 = 35.40 ± 1.78 and 35.38 ± 1.78 μM, respectively) though moderate compared to nintedanib (IC50 = 0.53 ± 0.11 and 0.74 ± 0.15 μM, respectively). The test compounds generally exhibited reduced cytotoxicity against the Vero cells compared to this anticancer drug. Molecular docking revealed strong alignment of the test compounds with the enzyme backbone to engage in hydrogen bonding interaction/s and hydrophobic contacts with the residues in the active sites of α-glucosidase and α-amylase. The test compounds possess favorable drug-likeness properties, supporting their potential as therapeutic candidates against T2DM.

Synthesis, biological evaluation, docking and molecular dynamics studies of Biginelli-type tetrahydropyrimidine analogues: Antimicrobial, cytotoxicity and antioxidant activity

Tetrahydropyrimidines have a fascinating scaffold that has garnered substantial attention from pharmacists and medicinal chemists. They are heterocyclic compounds used in anti-cancer, anti-microbial, and antioxidants therapies. Herein, a group of tetrahydropyrimidines were provided by using urea, α-ketoacid/β-ketoester, and appropriate aromatic aldehydes. Then, the antioxidant properties of the derivatives were investigated by the DPPH assay. Besides, the cytotoxicity activity of derivatives was evaluated on two MCF-7 and HepG-2 cell lines. The anti-microbial activity of derivatives was also assessed on two positive gram strains, two negative gram strains, and a fungal strain. Derivatives 4a and 4e showed the strongest antioxidant properties, with IC50s of 0.83 and 0.07 mg/mL, respectively. Compounds 4a and 4d were the most potent compounds, with IC50s of 15.81 and 12.34 µM, respectively, on both cancer cell lines. Furthermore, compounds 4b, 4j, and 4i showed the highest anti-microbial activity on S. aureus (MIC = 7.31 µM), B. subtilis (MIC = 10.81 µM), and E. coli (MIC = 11.45 µM), P. aeruginosa (MIC = 8.12 µM), and C. albicans (MIC = 12.03 µM), respectively. Then, the oral bioavailability and pharmacokinetic properties of compounds were predicted. Moreover, the most possible sites of the molecules that are metabolized by the main cytochromes were estimated. Then, the in silico cardiotoxicity and Cyto-safe properties of the compounds were studied. Finally, to determine the stability of the analogues in the Eg5 active site, docking and molecular dynamics simulations were performed.

Exploring Acyl Thiotriazinoindole Based Pharmacophores: Design, Synthesis, and SAR Studies with Molecular Docking and Biological Activity Profiling against Urease, α-amylase, α-glucosidase, Antimicrobial, and Antioxidant Targets.

A diminutive chemical library of acyl thiotriazinoindole (ATTI) based bioactive scaffolds was synthesized, instigated by taking the economical starting material Isatin, through a series of five steps. Isatin was first nitrated followed by the attachment of pentyl moiety via nucleophilic substitution reaction. The obtained compound was reacted with thiosemicarbazide to obtain thiosemicarbazone derivative, which was eventually cyclized using basic conditions in water as solvent. Finally, the reported series was obtained through reaction of nitrated thiotriazinoindole moiety with differently substituted phenacyl bromides. The synthesized compounds were characterized using NMR spectroscopy and elemental analysis. Finally, the synthesized motifs were scrutinized for their potential to impede urease, α-glucosidase, DPPH, and α-amylase. Compound 5h with para cyano group manifested the most pivotal biological activity among all, displaying IC50 values of 29.7 ± 0.8, 20.5 ± 0.5 and 36.8 ± 3.9µM against urease, α-glucosidase, and DPPH assay, respectively. Simultaneously, for α-amylase compound 5g possessing a p-CH3 at phenyl ring unfolded as most active, with calculated IC50 values 90.3 ± 1.1µM. The scaffolds were additionally gauged for their antifungal and antibacterial activity. Among the tested strains, 5d having bromo as substituent exhibited the most potent antibacterial activity, while it also demonstrated the highest potency against Aspergillus fumigatus. Other derivatives 5b, 5e, 5i, and 5j also exhibited dual inhibition against both antibacterial and antifungal strains. The interaction pattern of derivatives clearly displayed their SAR, and their docking scores were correlated with their IC50 values. In molecular docking studies, the importance of interactions like hydrogen bonding was further asserted. The electronic factors of various substituents engendered variety of interactions between the ligands and targets implying their importance in the structures of the synthesized heterocyclic scaffolds. To conclude, the synthesized compounds had satisfactory biological activity against various important targets. Further studies are therefore encouraged by attachment of different substitutions in the structure at various positions to enhance the activity of these compounds.

Novel 3,5‐Dimethylpyrazole‐Linked 1,2,4‐Triazole‐3‐thiols as Potent Antihyperglycemic Agents: Synthesis, Biological Evaluation, and In Silico Molecular Modelling Investigations

AbstractIn this work, a series of pyrazole‐linked 1,2,4‐triazole‐3‐thiol derivatives (3a–i) were prepared and identified by 13C NMR, 1H NMR, and mass spectrometry (ESI‐MS) data. The newly synthesized molecules were also evaluated in vitro for their α‐amylase and α‐glucosidase inhibitory potential. All newly synthesized compounds exhibited potent α‐glucosidase inhibition activity with IC50 in the range of 1.016 ± 0.70 to 24.40 ± 0.02 µM and good α‐amylase inhibitory with IC50 in the range of 49.91 ± 0.32 to 500 µM, as compared to acarbose. The most potent compound among this series is derivative 3e, with IC50 value of 1.016 ± 0.70 µM, which is many folds more than that of acarbose. In addition, in docking studies, both compounds exhibited good interactions at the active region of target proteins. Therefore, this study may lead via structural modifications to the discovery of new potent α‐amylase and α‐glucosidase inhibitors useful in the diabetes treatment.

Design, Synthesis, Computational Study, and Biological Evaluation of Sulfonyl Tethered Piperazine Derivatives as Antimicrobial Agents

AbstractPiperazine, a nitrogen‐containing heterocyclic compound, has potential in medical chemistry due to its versatile structure and ease of modification. Therefore, researchers have designed novel piperazine derivatives with various biological activities, including antiviral, antibacterial, and antifungal properties. In this study, a new series of 2‐(4‐((5‐bromo‐2‐methoxyphenyl)sulfonyl) piperazine‐1‐yl) acetamide derivatives (7a‐l) were synthesized and their structures were identified using 1H‐NMR, 13C‐NMR, and HRMS spectroscopic methods. The in vitro antimicrobial activity of these compounds was tested against four bacterial strains and two fungi strains. Some of the sulfonyl piperazine derivatives (7d, 7e, 7f, 7j, 7k, and 7l) exhibited relatively good antimicrobial and antifungal activities compared to standard drugs. Further analysis using computational docking confirmed strong binding interactions, aligning with our results. Our compounds exhibited improved potency compared to existing standard treatments.

Experimental and computational profiling of novel bis-Schiff base derivatives bearing α-naphthalene moiety as potential tyrosinase inhibitors

A library of novel bis-Schiff base derivatives (2a-u) of α-naphthalene moiety was successfully synthesized by four step reactions. Following structural elucidation, these products were evaluated for their in vitro tyrosinase inhibitory potential. In the series, nine derivatives (2e, 2r, 2t, 2 g, 2 u, 2p, 2a, 2d, and 2 h) attributed excellent inhibitory activity in the range of IC50 values from 2.3 ± 1.7 to 17.6 ± 0.9 µM superior to the standard drug kojic acid. Similarly, four compounds showed significant activities near to the standard while the remaining eight compounds displayed good to moderate inhibition with IC50 values from 29.3 ± 2.9 to 63.2 ± 1.1 µM. The molecular docking investigations for most active compounds (2e, 2r, 2t, 2 g, 2 u, 2p, 2a, 2d, and 2 h) form high stability in binding site of the tyrosinase active site, than standard kojic acid. Frontier molecular orbitals, such as HOMO and LUMO to show the charge transfer from molecule to biological medium and MEP map to show the chemically reactive zone appropriate for drug action, are calculated using TD-DFT. Besides, the drug-likeness prediction showed that these compounds showed a desirable property, such as high intestinal absorption, large volume of distribution, good BBB penetration, and low toxicity. These bis-Schiff bases have a high oral bioavailability, which can categorized as a unique drug candidate in future.

Synthesis and Preliminary Anticancer Evaluation of 4-C Derivatives of Diphyllin.

The natural lignan diphyllin has shown promising antitumor activity, although its clinical advancement has been impeded by challenges such as low solubility, poor metabolic stability, and limited potency. In response, we developed and synthesized two sets of diphyllin 4-C derivatives, comprising six ester derivatives and eight 1, 2, 3-triazole derivatives. Notably, among these derivatives, 1, 2, 3-triazole derivatives 7c and 7e demonstrated the most potent cytotoxic effects, with IC50 values ranging from 0.003 to 0.01 μM. Treatment with 0.2 μM of 7c and 7e resulted in a reduction of V-ATPase activity in HGC-27 cells to 23% and 29%, respectively.