Novel Polyhydroquinoline-Hydrazide-Linked Schiff’s Base Derivatives: Multistep Synthesis, Antimicrobial, and Calcium-Channel-Blocking Activities

Polyhydroquinoline (PHQ) are the unsymmetrical Hantzsch derivatives of 1,4-dihydropyridines with several biological applications. In this work, twenty-five (<b>3</b>–<b>27</b>) new Schiff’s base derivatives of polyhydroquinoline hydrazide were synthesized in excellent to good...

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Main Authors: Zainab, Haitao Yu, Najeeb Ur Rehman, Mumtaz Ali, Aftab Alam, Abdul Latif, Nazish Shahab, Irfan Amir Khan, Abdul Jabbar Shah, Momin Khan, Ahmed Al-Ghafri, Ahmed Al-Harrasi, Manzoor Ahmad
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Antibiotics
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Online Access:https://www.mdpi.com/2079-6382/11/11/1568
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Summary:Polyhydroquinoline (PHQ) are the unsymmetrical Hantzsch derivatives of 1,4-dihydropyridines with several biological applications. In this work, twenty-five (<b>3</b>–<b>27</b>) new Schiff’s base derivatives of polyhydroquinoline hydrazide were synthesized in excellent to good yields by a multi-component reaction. The structures of the synthesized products (<b>1</b>–<b>27</b>) were deduced with the help of spectroscopic techniques, such as <sup>1</sup>H-, <sup>13</sup>C -NMR, and HR-ESI-MS. The synthesized products (<b>1</b>–<b>27</b>) were tested for their antibacterial and in vitro calcium -channel-blocking (CCB) potentials using the agar-well diffusion method, and isolated rat aortic ring preparations, respectively. Among the series, sixteen compounds were found to inhibit the growth of <i>Escherichia coli</i> and <i>Enterococcus faecalis</i>. Among them, compound <b>17</b> was observed to be the most potent one at a dose 2 µg/mL, with an 18 mm zone of inhibition against both bacteria when it was compared with the standard drug amoxicillin. Eight compounds showed CCB activity of variable potency; in particular, compound <b>27</b> was more potent, with an EC<sub>50</sub> value of 0.7 (0.3–1.1) µg/mL, indicating their CCB effect.
ISSN:2079-6382