New Quinoline Linked Chalcone and Pyrazoline Conjugates: Molecular Properties Prediction, Antimicrobial and Antitubercular Activities

Abstract

Two novel series comprising of forty two compounds have been synthesized by conjugating quinoline scaffold with chalcone as well as pyrazoline motifs. All the synthesized conjugates were tested for their antibacterial, antifungal and anti‐tubercular activities. Several of these novel compounds exhibited good to appreciable antibacterial activity against the tested bacterial strains. Compounds 4 j and 7 b were found to be the promising candidates exhibiting MIC 4 μg/mL against B. subtilisMTCC 121 and M. luteus MTCC 2470. Moreover, several conjugates significantly inhibited growth of certain fungal organisms. Furthermore, some of the conjugates displayed moderate anti‐tubercular activity against both H37RV as well as RifR strains. The binding modes and effect of the C4 quinoline substitution on the activity have been studied using computational techniques. Methyl group enhances the antimicrobial activity upon replacement by aromatic phenyl group and this is supported by the experimental data.

Effective and Sustainable Access to Quinolines and Acridines: A Heterogeneous Imidazolium Salt Mediates C–C and C–N Bond Formation

“…Moreover, chalcone derivatives are also interesting due to their potential bioactivities as antitumoral, anti‐HIV, antioxidant and antituberculosis, among others . In this sense, quinolyl chalcones represent a type of family compounds which is of interest to be considered in pharmacological studies . To explore further the versatility of our catalytic system, we envisioned the possibility of performing an aldol coupling in the presence of bcmim‐Cl , allowing the preparation of quinolyl chalcones starting from the 3‐acetylquinoline 5af .…”

“…( E )‐3‐(3‐Hydroxy‐4‐methoxyphenyl)‐1‐(2‐methyl‐4‐phenylquinol‐3‐yl)prop‐2‐en‐1‐one (7a): Yellow solid; purification by recrystallization in CH 2 Cl 2 , 66 % yield; m.p. : 220–222 °C (CH 2 Cl 2 ) (Lit.…”

“…: 220–222 °C (CH 2 Cl 2 ) (Lit. : 213 °C); IR (ATR): ν̃ = 1624, 1601, 1507, 1440, 1284, 1232, 1168, 1133, 1051, 1024, 778, 754, 725 cm –1 ; 1 H NMR (300 MHz, CDCl 3 ): δ H = 8.22 (d, J = 8.5 Hz, 1H, CH Ar ), 7.77 (ddd, J = 8.4, 6.8 and 1.5 Hz, 1H, CH Ar ), 7.64 (dd, J = 8.5 and 1.4 Hz, 1H, CH Ar ), 7.55–7.43 (m, 1H, CH Ar ), 7.38 (dd, J = 5.1 and 2.0 Hz, 3H, 3 × CH Ar ), 7.35–7.26 (m, 2H, 2 × CH Ar ), 7.01 (d, J = 16.2 Hz, 1H, ArCH), 6.93 (d, J = 2.0 Hz, 1H, CH Ar ), 6.87–6.75 (m, 2H, 2 × CH Ar ), 6.45 (d, J = 16.1 Hz, 1H, COCH), 3.89 (s, 3H, OCH 3 ), 2.74 (s, 3H, CCH 3 ) ppm; 13 C NMR (101 MHz, CDCl 3 ): δ C = 197.3, 155.1, 149.6, 147.2, 146.2, 145.9, 130.4, 130.0, 128.7, 128.5, 126.8, 126.5, 126.2, 122.6, 113.4, 110.8, 105.4, 56.1, 23.7 ppm; MS (DIP, EI): m/z 396 (M + + 1, 27 %), 395 (M + , 100), 394 (47), 380 (14), 367 (12), 366 (35), 258 (24), 218 (25), 217 (25), 177 (23), 176 (25), 151 (12), 137 (14), 89 (12); HRMS (GC/MS‐EI/Q‐TOF): m/z calcd. for C 26 H 21 NO 3 395.1521, found 395.1526.…”

Synthesis of 1‐Substituted Pyrazolines by Reaction of Donor‐Acceptor Cyclopropanes with 1,5‐Diazabicyclo[3.1.0]hexanes

“…Azaheterocyclic scaffolds are present in more than half of small molecules approved for the use as pharmaceuticals Among them, pyrazolines (2,3‐dihydro‐1 H ‐pyrazoles) occupy an important place. In particular, edaravone is used for the treatment of amyotrophic lateral sclerosis and to assist the recovery of patients after a cerebral ishemic stroke, eltrombopag is efficient for the treatment of idiopathic thrombocytopenic purpura and hepatitis C‐induced cirrhosis, muzolimine is a diuretic, rosonabant, ibipinabant and related compounds efficiently bind to cannabinoid CB 1 receptor providing appetite suppressant effect, some other pyrazolines were found to demonstrate antimicrobial, anti‐inflammatory, antiamoebic, and other bioactivities . Some of these compounds are given in Figure .…”

Synthesis and physicochemical studies of vanillin chalcones

“…Chalcones are one of the most important classes of flavonoids across the whole plant kingdom [1,2]. The chemistry of chalcones has generated intensive scientific studies throughout the world due to the large number of replaceable hydrogens that allows a large number of derivatives and a variety of promising biological activities to be generated e.g., anti-microbial [3], anti-cancer [4], anti-inflammatory [5], anti-malarial [6], anti-allergic [7], anti-oxidant [8], anti-infective [9], anti-influenze [10], anti-protozoal [11] etc. In modified form, these compounds are widely distributed in foods and beverages such as vegetables, fruits, tea, soy-based foodstuff and spices [12,13].…”