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University of Delhi (DU) has attained global recognition for its research and teaching in Chemistry. This Guest Editorial introduces the research showcased in the "Institute Feature: Celebrating 100 Years of University of Delhi (1922–2022)" ‐ a joint special collection from the European Journal of Organic Chemistry (EurJOC), European Journal of Inorganic Chemistry (EurJIC) and ChemistrySelect The collection highlights the contributions to the field of chemistry through research articles and reviews authored by faculty members from the Department of Chemistry, alumni of the department and faculty members of chemistry department of various colleges affiliated with the university, celebrating 100 years of DU. [ABSTRACT FROM AUTHOR]

An exceptionally productive, rapid, simple, and eco-friendly approach for the synthesis of 2,3-dihydroquinazolin-4(1H)-one has been developed utilizing acidic magnetically retrievable cobalt ferrite nanoparticles (CFNP@SO3H). Herein, we have demonstrated the synthesis of these profoundly demanding N-heterocyclic molecules within 3–10 min in excellent yields at room temperature using the environmentally benign solvent ethanol. Outstanding catalytic performance, ease of retrievability, high turnover frequency (TOF) values (197.13–403.23 h−1), admirable green chemistry metrices, such as the E factor (0.10), reaction mass efficiency (RME) value (90.9%), carbon efficiency (100%) and atom economy (AE) value (92.6%), and reusability for up to six runs without a significant loss of activity, make the current methodology advantageous from an environmental, as well as industrial perspective. [ABSTRACT FROM AUTHOR]

Tetrazoles are synthetic organic heterocyclic compounds comprising of high nitrogen content among stable heterocycles. Tetrazoles, chiefly 5-substituted 1 H -tetrazoles have been used as a bioisosteric replacement for carboxylic acids in medicinal chemistry. Various clinical drugs, including losartan, cefazolin, and alfentanil, contain the tetrazole moiety. There have been significant developments in the synthesis of 5-substituted 1 H -tetrazoles. Researchers are still working to develop more efficient and ecofriendly methods for their synthesis. In this review, we provide a comprehensive discussion of the recent advancements in the field of synthesis of 5-substituted 1 H -tetrazoles. 1 Introduction 2 The Role of 5-Substituted 1 H -Tetrazoles in Medicinal Chemistry 3 Synthesis of 5-Substituted 1 H -Tetrazoles 3.1 Microwave-Assisted Synthesis 3.2 Heterogeneous Catalysts 3.3 Nanoparticles as Heterogeneous Catalysts 3.4 Miscellaneous Methods 4 Sartans: A Class of Tetrazole-Based Commercial Drugs 5 Conclusions [ABSTRACT FROM AUTHOR]

This article provides a comprehensive report on the rhodium(III)-catalyzed C–H activation in indole from 2017 to 2022. The direct functionalization of C–H bonds offers a more sustainable and economically sensible route in organic synthesis, reducing the production of hazardous waste. Rhodium has been widely used as a catalyst for C–H functionalization due to its excellent functional group compatibility, versatility, reactivity, and selectivity. The article focuses on the utilization of Rh(III) catalyst for C–H activation of the indole moiety, which is a structurally important building block in natural products and pharmaceutical treatments. Various methods for directed C–H functionalization of indoles, such as C2 activation, alkylation, hydroarylation, and dual C–H activation reactions, are discussed. The text also discusses various methods for the synthesis of carbazole derivatives, benzo[e]indoles, and selective functionalization of indoles through C–H activation. While progress has been made in this area, there are still challenges to overcome, such as the need for harsh reaction conditions and stoichiometric metal oxidants. Continued research in this field is expected to improve reaction conditions and increase overall efficiency. [Extracted from the article]

Describes the structure of the designed beta-hairpin peptide in crystals. Presence of Type II' or Type I' beta-turns; Experimental methods used in peptide synthesis; Conformations of the two independent molecules in the assymetric unit; Enhancement of crystallization with the introduction of alpha-aminoisobutyric acid; Critical interstand nuclear Overhauser effects in apolar solvents.

Herein, we synthesized guanidine functionalized graphene oxide nanocomposites referred to GO‐GN NCs using hummer's method. GO‐GN NCs was characterized using Fourier‐Transform Infrared Spectroscopy, Powder X‐ray Diffraction, Thermogravimetric Analysis, Raman Spectroscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer‐Emmett‐Teller (BET) surface area analysis to confirm successful formation of GO‐GN NCs catalysts. The catalytic performance for GO‐GN NCs was evaluated for Knoevenagel and Aldol condensation reaction in aqueous medium at ambient condition and result shows that it could be used as a highly efficient, stable, and durable catalyst. In addition, it has another feature such as easy workup procedure, large substrate tolerance, high reaction yield, good recyclability, and environmental friendliness. [ABSTRACT FROM AUTHOR]

Sulfonated reduced graphene oxide (SrGO) has displayed great potential as a solid acid catalyst due to its efficiency, cost-effectiveness, and reliability. In this study, SrGO was synthesized by the introduction of sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide using ultrasonication. The SrGO catalyst was characterized by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Further, SrGO was effectively utilized as a metal-free and reusable solid acid catalyst for the chemoselective N - t -Boc protection of various aromatic and aliphatic amines under solvent-free conditions. The N - t -Boc protection of amines was easily achieved under ambient conditions affording high yields (84–95%) in very short reaction times (5 min–2 h). The authenticity of the approach was confirmed by a crystal structure. The catalyst could be easily recovered and was reused up to seven consecutive catalytic cycles without any substantial loss in its activity. [ABSTRACT FROM AUTHOR]

Heteroleptic copper(II)-polypyridyl complexes with extended p-conjugated, aromatic terminal units were immobilized on glass/Si substrates to intercalate DNA and cleave it upon photoexposure. Photonuclease activity is shown to be high, well reproducible and non-destructible towards the assembled complexes. [ABSTRACT FROM AUTHOR]

The interaction of triazole substituted 4‐methyl‐7‐hydroxycoumarin derivatives (CUM1‐4) with serum albumin (bovine serum albumin [BSA] and human serum albumin [HSA]) have been studied employing ultraviolet‐visible (UV‐Vis), fluorescence, circular dichroism (CD) spectroscopy, and molecular docking methods at physiological pH 7.4. The fluorescence quenching occurred with increasing concentration of CUMs, and the binding constant of CUM derivatives with BSA and HSA obtained from fluorescence quenching experiment was found to be ~ 104 L mol−1. CD study showed conformational changes in the secondary structure of serum albumin upon titration of CUMs. The observed experimental results were further validated by theoretical studies involving density functional theory (DFT) and molecular docking. [ABSTRACT FROM AUTHOR]

Twenty two diverse coumarin-triazole derivatives were synthesized by alkylation of 7-hydroxy-4-methyl-coumarin followed by click chemistry at 7-position. These compounds were evaluated for their in vitro antiplasmodial activity against chloroquine sensitive strain of Plasmodium falciparum (3D7). Compound 9 (7-[1-(2, 4-dimethoxy-phenyl)-1H- [1–3] triazol-4-ylmethoxy]-4-methyl-chromen-2-one) was found most active with IC 50 value 0.763 ± 0.0124 μg/mL. Further, the structure of compound 20 was characterized by single crystal X-ray diffraction. In view of impressive results, we considered it worthwhile to validate the results of in vitro antiplasmodial activity by assessing whether these compounds are capable of hampering the catalytic activity of DNA gyrase, thus preventing its supercoiling function. [ABSTRACT FROM AUTHOR]

Synthetic quinoline derivatives continue to be considered as candidates for new drug discovery if they act against CQ-resistant strains of malaria even after the widespread emergence of resistance to CQ. In this study, we explored the activities of two series of new 4-aminoquinoline derivatives and found them to be effective against Plasmodium falciparum under in vitro conditions. Further, we selected four most active derivatives 1m, 1o, 2c and 2j and evaluated their antimalarial potential against Plasmodium berghei in vivo . These 4-aminoquinolines cured BALB/c mice infected with P. berghei . The ED 50 values were calculated to be 2.062, 2.231, 1.431, 1.623 and 1.18 mg/kg of body weight for each of the compounds 1m, 1o, 2c, 2j and amodiaquine, respectively. Total doses of 500 mg/kg of body weight were well received. The study suggests that these new 4-aminoquinolines should be used for structure activity relationship to find lead molecules for treating multidrug-resistant Plasmodium falciparum and Plasmodium vivax . [ABSTRACT FROM AUTHOR]

Selective detection of sulfur mustard simulant, 2-chloroethyl ethyl sulfide ( CEES ) is performed using specifically designed pyridine appended Mg–porphyrazine complex ( 1 ). Interaction of CEES with pyridine units of 1 leads to perturbation/reduction in absorbance of the Q-band of 1 and the process is, thus, monitored using UV–vis spectroscopic method. Interestingly, treating the CEES- 1 solution with KMnO 4 solution results in reappearance of Q-band of 1 and allows reuse of 1 by simple filtration. The alkylating ability of CEES and KMnO 4 oxidation of CEES- 1 appears to be playing an important role in the detection/degradation process, thereby serving the dual purpose. The chemical sensing is then used as a platform for generating different input-based combinatorial and sequential molecular logic gate(s) allowing facile information processing and as an information security system in the form of a keypad lock. [ABSTRACT FROM AUTHOR]

The artemisinin resistance has posed a serious threat against malaria elimination lately. Past few years have seen important development of several peroxide based medicinal compounds and their derivatives such as trioxanes and tetraoxanes. Here, we report a rapid, one-pot method for synthesizing a new series of N -sulfonylpiperidine dispiro-1,2,4,5-tetraoxane analogs with diverse substitution on the tetraoxane ring i.e., various substituted alkyl and aryl sulfonyl chlorides, as well as cyclic, acyclic and aryl substituted ketones. All the synthesized tetraoxanes were characterized by spectroscopic (1H NMR,13C NMR), and spectrometric (High-resolution mass spectrometry) techniques and quantify by High Performance Liquid Chromatography (HPLC) analysis. The structure of compound 19 was confirmed by single crystal XRD. From the overall preliminary in vitro data, analogs 14, 16, 19, 20, 24, 41, and 44 exhibited potential IC 50 values in the nanomolar range between 4.7 ± 0.3 to 12.9 ± 1.1 nM against P. falciparum (Pf 3D7) strains of human malaria parasite. Furthermore, these selective analogs were evaluated in vivo for their antimalarial potential against P. berghei and results revealed that analogue 24 rapidly kills the infected cell at asexual erythrocytic stage, with activity comparable to positive control chloroquine. [Display omitted] • Synthesis ofg N -sulfonylpiperidine dispiro-1,2,4,5-tetraoxane analogs. • Compounds were characterized by various techniques such as 1H NMR, 13C NMR, HRMS (High-resolution mass Spectrometry) and single crystal X-ray diffraction (XRD) analysis. • Anti-plasmodial activities of the 41 analogs were evaluated against P. falciparum in vitro. • Selective analogs 14, 16, 19, 20, 24, 41 , and 44 were evaluated in vivo for their antimalarial potential against P. berghei and compound 24 exhibited the most potent fast killing antimalarial efficacy against asexual erythro-cytic stage. [ABSTRACT FROM AUTHOR]

An abstract of the article "Design and Synthesis of a s-Triazene Based Asymmetric Organocatalyst and Its Application in Enantioselective Alkylation" by Shrawan K. Mangawa and colleagues is presented.

A new simple and efficient fluorous coupling reagent TriTFET (2,4,6-tris-(2,2,2-trifluoro-ethoxy)-[1,3,5] triazene) has been designed and synthesized for the direct amidation. The use of 5 mol % of TriTFET is good for the amide synthesis from carboxylic acids with amines in moderate to excellent yields (72–96%). [ABSTRACT FROM AUTHOR]

Background: Emergence of drug-resistant parasite strains has surfaced as a major obstacle in attempts to ameliorate malaria. Current treatment regimen of malaria relies on the concept of artemisinin-based combination therapy (ACT). Methods: Fluoroquinolone analogues, compounds 10, 12 and 18 were investigated for their anti-malarial interaction in combination with artemisinin in vitro, against Plasmodium falciparum 3D7 strain, employing fixed-ratio combination isobologram method. In addition, the efficacy of these compounds was evaluated intraperitoneally in BALB/c mice infected with chloroquine-resistant Plasmodium berghei ANKA strain in the Peters' four-day suppressive test. Results: Promising results were obtained in the form of synergistic or additive interactions. Compounds 10 and 12 were found to have highly synergistic interactions with artemisinin. Antiplasmodial effect was further verified by the convincing ED50 values of these compounds, which ranged between 2.31 and 3.09 (mg/kg BW). Conclusions: In vivo studies substantiated the potential of the fluoroquinolone derivatives to be developed as synergistic partners for anti-malarial drug combinations. [ABSTRACT FROM AUTHOR]

Abstract: In an attempt to design and synthesize a new class of antimicrobials, dialkyne substituted 2-aminobenzothiazole was reacted with various substituted aryl azides to generate a small library of 20 compounds (3a–t) by click chemistry. Structures of the newly synthesized compounds were established on the basis of spectral data. These compounds were screened for their antibacterial activity against Gram+ bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram− bacteria (Salmonella typhi, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella boydii) and antifungal activity against Candida tropicalis, Candida albicans, Candida krusei, Cryptococcus neoformans) as well as molds (Aspergillus niger, Aspergillus fumigatus). The compound 3e showed maximum potency against all Gram+/gram− bacterial strains with MIC value 3.12 μg/ml, which is two fold more active as compared to standard drug ciprofloxacin (MIC 6.25 μg/ml). However, all compounds were found ineffective against S. boydii (clinical isolate). Further, only one compound 3n was found to be the most active against all fungal strains with MIC value in the range of 1.56 μg/ml–12.5 μg/ml while the remaining compounds showed moderate to weak antifungal activity. [Copyright &y& Elsevier]

Twenty-seven novel chalcone derivatives were synthesized using Claisen-Schmidt condensation and their antimalarial activity against asexual blood stages of Plasmodium falciparum was determined. Antiplasmodial IC50 (half-maximal inhibitory concentration) activity of a compound against malaria parasites in vitro provides a good first screen for identifying the antimalarial potential of the compound. The most active compound was 1-(4-benzimidazol-1-yl-phenyl)-3-(2, 4-dimethoxy-phenyl)-propen-1-one with IC50 of 1.1 μg/mL, while that of the natural phytochemical, licochalcone A is 1.43 μg/mL. The presence of methoxy groups at position 2 and 4 in chalcone derivatives appeared to be favorable for antimalarial activity as compared to other methoxy-substituted chalcones. Furthermore, 3, 4, 5-trimethoxy groups on chalcone derivative probably cause steric hindrance in binding to the active site of cysteine protease enzyme, explaining the relative lower inhibitory activity. [ABSTRACT FROM AUTHOR]

Abstract: Fluoroquinolone analogs were synthesized by simple alkylation followed by click chemistry and evaluated for their antimalarial in vitro against chloroquine sensitive strain of Plasmodium falciparum while ciprofloxacin was used as standard. Our results showed that the compound 12 was found most active with IC50 value of 1.33 μg/mL while ciprofloxacin showed IC50 = 8.81 μg/mL. Therefore, screening of either known or unknown quinolone/fluoroquinolone analogs are worthwhile to find more potent antimalarial drugs which might prove useful in the treatment of mild or severe malaria in human either alone or in combination with existing antimalarial drugs. [Copyright &y& Elsevier]

Abstract: Use of artemisinin based combination therapies (ACTs) is increasing in treatment of malaria. Their extensive and indiscriminate deployment will ultimately lead to selection of resistance. Thus, alternate ACTs are needed. We reported in vitro antimalarial potential of chalcone derivatives. A few potent chalcones were selected for their antimalarial interaction in combination with artemisinin in vitro. Combinations evaluated show synergistic or additive interactions. Chalcones act on broad range of asexual stages of the parasite. The synergistic combinations decrease hemozoin formation in parasitized erythrocytes. These combinations do not affect new permeation pathways induced in the host cells. This is the first report showing antiplasmodial interactions between artemisinin and synthetic chalcone azole derivatives. Thus, chalcones and artemisinin combinations open the possibility of novel ACTs. [Copyright &y& Elsevier]

Abstract: The synthesis of novel 1,3-diaryl propenone derivatives and their antimalarial activity in vitro against asexual blood stages of human malaria parasite, Plasmodium falciparum, are described. Chalcone derivatives were prepared via Claisen–Schmidt condensation of substituted aldehydes with substituted methyl ketones. Antiplasmodial IC50 (half maximal inhibitory concentration) activity of these compounds ranged between 1.5 and 12.3μg/ml. The chloro-series, 1,2,4-triazole substituted chalcone was found to be the most effective in inhibiting the growth of P. falciparum in vitro while pyrrole and benzotriazole substituted chalcones showed relatively less inhibitory activity. This is the first report on antiplasmodial activity of chalcones with azoles on acetophenone ring. [Copyright &y& Elsevier]

Emergence and spread of Plasmodium falciparum resistant to artemisinin-based combination therapy has led to a situation of haste in the scientific and pharmaceutical communities. Sincere efforts are redirected towards finding alternative chemotherapeutic agents that are capable of combating multidrug-resistant parasite strains. Extensive research yielded the concept of "Chimeric Bitherapy (CB)" which involves the linking of two molecules with individual pharmacological activity and exhibit dual mode of action into a single hybrid molecule. Current research in this field seems to endorse hybrid molecules as the next-generation antimalarial drugs and are more effective compared to the multi-component drugs because of the lower occurrence of drug-drug adverse effects. This review is an attempt to congregate complete survey on endoperoxide based hybrid antiplasmodial molecules that will give glimpse on the future directions for successful development and discovery of useful antimalarial hybrid drugs. [Display omitted] • "Chimeric Bitherapy (CB)" has been developed against endemic malaria to avoid the emergence of drug-resistant strains. • CB means connecting of two atoms via covalent linker which has individual intrinsic activity into a single hybrid molecule. • Chimeric hybrid (CH) has potential to prevent drug resistance due to their multiple mechanism of action. • CH plays a pivotal role in malaria eradication owing to good solubility, low toxicity and increased biopharmaceutical efficacy. • Hybrid drugs are more superior than the combination drugs as they have lower occurrence of drug-drug adverse effects. [ABSTRACT FROM AUTHOR]

• Conversion of hazardous sulfonic acid for the safer and active structural fragment of catalyst. • The safer nanocatalyst can be recovered effortlessly from reaction mixture using external magnet. • 20 examples of 2-substituted benzimidazoles using aldehydes and o-phenylenediamine. • High stability of catalytic efficiency and reusability at least for 7 serial runs. • Excellent values of green chemistry metrices like E-factor, RME and AE values etc. This work represents the design and synthesis of efficient sulfonated cobalt ferrite solid acid catalyst. The synthesized solid acid green catalyst was characterized using various techniques viz. FT-IR, powder XRD, SEM, TEM and VSM. The obtained catalyst was used to synthesize biologically significant 2-substituted benzimidazole derivatives by condensation between o-phenylenediamine with various aromatic, aliphatic and heterocyclic aldehydes. High yield (up to 98 %), short reaction time (10−25 min), mild reaction condition, wide functional group tolerance, easy work-up procedure and excellent values of green chemistry metrices such as lower E factor (0.126), high RME value (88.83 %), carbon efficiency (100 %) and high atom economy (AE) value (90.65 %), are some salient features of the present catalytic system. Moreover, the catalyst recovery by simply using an external magnet and catalyst reusability up to 7 times without any significant loss in catalytic efficiency are some additional remarkable features of the current protocol. [ABSTRACT FROM AUTHOR]

• 4-Aminoquinolines were evaluated against CQ-resistant P. falciparum in combination with DHA. • Synergistic interactions were evidenced between the combination partners. • Combinations inhibited hemozoin formation with enhanced efficacy. • Partner compounds displayed distinct stage-specific profiles. High-grade chloroquine (CQ) resistance has been reported in malaria endemic geographical regions such as Papua New Guinea, northern Papua, and eastern and western provinces of Indonesia, along with low-level resistance in Vietnam, South Korea, Turkey, Burma, South America, and Madagascar. Studies on CQ drug resistance have revealed the association of P. falciparum chloroquine resistance transporter protein. Thus, we are in dire need of alternate chemotherapeutic agents which in combination with artemisinin (or its analogues) are efficacious against chloroquine-resistant strains. Such combinations may thwart the emergence of drug resistant strains, along with reducing the malaria burden. Hypothesizing that newer 4-aminoquinolines, earlier reported by our group, could be part of a combination therapy to efficiently treat malaria, we sought to evaluate these compounds, viz. 1m, 1o, 2c, and 2j against the erythrocytic stages of Plasmodium falciparum, strain 3D7 (chloroquine-sensitive) and strain Dd2 (chloroquine-resistant), in combination with dihydroartemisinin (DHA). Results revealed substantially synergistic interactions between the combination partners, which could be further established by their potential to inhibit hemozoin formation with increased efficiency when combined, as compared to the compounds assessed individually. Furthermore, aminoquinolines and DHA show distinct stage-specific profiles. Our results stand in strong support of the potential of these aminoquinoline derivatives to serve as partner drugs in antimalarial combinations to treat multiple-drug-resistant Plasmodium strains. [ABSTRACT FROM AUTHOR]

Various fluorinated alkyl and aryl ethers are eco-friendly obtained using the synthetic non-toxic, non-ozone depleting, and stable 2,4,6-tris-(2,2,2-trifluoroethoxy)-[1,3,5]triazene (II) as trifluoroethylation reagent. [ABSTRACT FROM AUTHOR]

Alkyl, benzyl, aryl, and hetaryl carboxylic acids are successfully coupled with primary aliphatic and aromatic amines as well as secondary aliphatic amines. [ABSTRACT FROM AUTHOR]

Quinolone derivative (I), obtained by a reported procedure, is alkylated at position 1 with normal and branched chain alkyl groups as well as some polar groups. [ABSTRACT FROM AUTHOR]