Reactions with Visnaginone: Synthesis, Cyclisation and Microbial Evaluation of Some Visnaginone Thiosemicarbazone Derivatives

Abstract

Several new visnaginone ethers were prepared and their thiosemicarbazone derivatives are synthesized. The behavior of the thiosemicarbazones in methanolic sodium methoxide and hydrochloric acid is discussed. Structures were established on the bases of elemental and spectral data studies. Some of the thiosemicarbazones were tested for their antimicrobial activity. The structures of the synthesized derivatives (5a-g,6a-g) were confirmed by means of IR, 1H NMR, MS and elemental analyses. The synthesized derivatives (5a-g,6a-g) wear subjected to the Microbiology Division, Microanalytical Center, Cairo University, (5a-g,6a-g) showed a variable degree of antimicrobial activity.

Synthesis of New Furothiazolo Pyrimido Quinazolinones from Visnagenone or Khellinone and Antimicrobial Activity

“…Remainder the compounds demonstrated a weak activity compared to the antimicrobial activity of the standard drugs (cefotaxime sodium and nystatin). The thiazolopyrimidine derivatives possessing verified to be effective as antimicrobial agents in previous articles [ 7 , 8 ]. Also, they were active against Staphylococcus aureus, E. coli, and Klebsiella pneumoniae [ 7 , 31 ] and they were also effective against Streptococcus pyogenes and species of fungi, namely, Aspergillus niger, Candida albicans [ 7 , 32 ].…”

“…The thiazolopyrimidine derivatives possessing verified to be effective as antimicrobial agents in previous articles [ 7 , 8 ]. Also, they were active against Staphylococcus aureus, E. coli, and Klebsiella pneumoniae [ 7 , 31 ] and they were also effective against Streptococcus pyogenes and species of fungi, namely, Aspergillus niger, Candida albicans [ 7 , 32 ]. In this work and previous reports, most bacteria and fungi types effected susceptible to this class of heterocyclic compounds [ 33 , 34 , 35 ].…”

“…As well, furochromone derivatives are reported as anti-atherosclerotic, antineoplastic, anti-gastric, anti-anaphylactic and are used in the treatment of urolithiasis, hypertriglyceridemia [ 4 , 5 ] and vitiligo [ 6 ]. Also, the visnaginone derivatives were synthesized using different procedures and elucidated efficient antimicrobial activities [ 7 , 8 ]. Furthermore, furochromones have been used to treat pain in the renal colic [ 9 ] and possesses coronary vasodilating activity [ 10 , 11 ].…”

Transalkylidation reaction: green, catalyst-free synthesis of thiosemicarbazones and solving the NMR conflict between their acyclic structure and intramolecular cycloaddition products

“…That was obvious in several published articles which reported identical spectral data for both thiosemicarbazones and their cycloaddition product (1,2,4-triazolidine-3-thiones). Thus, many authors incorrectly interpreted the NMR spectral data of alkylidene thiosemicarbazones and reported them as triazolidine-3-thiones (45)(46)(47)(48)54,55,57), this confusion arises from the presence of three exchangeable N-H signals in both structures. Herein, we would like to report a green and simple method for synthesis of alkylidene thiosemicarbazide and clarify the structural elucidation confusion between alkylidene thiosemicarbazide, and their cyclized forms.…”