Synthesis and Evaluation of Bicyclo[3.1.0]hexane-Based UDP-Galf Analogues as Inhibitors of the Mycobacterial Galactofuranosyltransferase GlfT2

In Silico Evaluation Of Some Commercially Available Flavonoids As Galactofuranoyltransferase-2 Inhibitors In The Management Of Tuberculosis

Background:

Background: Galactofuranoyltransferase-2 (GlfT2) enzyme involved in the galactan polymerization of the arabinogalactan (AG) region of the mycolylarabinogalactan-peptidoglycan (mAGP) complex, an important component of the mycobacterial cell wall

Objective:

Objective: With the existing challenge the study focused into identifying certain commercially available flavonoids through molecular docking studies against the Galactofuranoyltransferase-2 enzyme.

Methods:

Methods: The initial pharmacokinetic screening was carried out using Lipinski’s rule of 5 with the help of Molinspiration software. In this perspective, Apigenin, Kaempferol, Rutin, Silibinin and Vitexicarpin were selected for the current study. Except for rutin all other selected flavonoids did not show any violations and thereby selected for the docking studies using AutoDock 4.2.

Results:

Results: The docking results showed that the selected flavonoids have excellent binding energy values between −8.98 to −6.58 kcal/mol against the GlfT2 enzyme. The theoretical inhibition constant was found to be in the range of 260.90 nM to 15.13 µM which coincides with the binding energies of the selected compounds.

Conclusion:

Conclusion: From the selected flavonoids, Silibinin showed excellent binding scores and it has the potential to inhibit the GlfT2 enzyme. Silibinin could act as a novel GlfT2 inhibitor with promising therapeutic activity with low toxicity profile against tuberculosis

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

A series of ten novel ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones bearing a 1-O-phosphono moiety and three different substituents at C-2 has been prepared. Due to the structural similarities of these scaffolds to the native substrate of mycobacterial galactofuranosyltransferase GlfT2 in the transition state, we evaluated these compounds by computational methods, as well as in an enzyme assay for the possible inhibition of the mycobacterial galactan biosynthesis. Our data show that despite favorable docking scores to the active site of GlfT2, none of these compounds serve as efficient inhibitors of the enzymes involved in the mycobacterial galactan biosynthesis.

Biosynthesis of Galactan in Mycobacterium tuberculosis as a Viable TB Drug Target?

While target-based drug design has proved successful in several therapeutic areas, this approach has not yet provided compelling outcomes in the field of antibacterial agents. This statement remains especially true for the development of novel therapeutic interventions against tuberculosis, an infectious disease that is among the top ten leading causes of death globally. Mycobacterial galactan is an important component of the protective cell wall core of the tuberculosis pathogen and it could provide a promising target for the design of new drugs. In this review, we summarize the current knowledge on galactan biosynthesis in Mycobacterium tuberculosis, including landmark findings that led to the discovery and understanding of three key enzymes in this pathway: UDP-galactose mutase, and galactofuranosyl transferases GlfT1 and GlfT2. Moreover, we recapitulate the efforts aimed at their inhibition. The predicted common transition states of the three enzymes provide the lucrative possibility of multitargeting in pharmaceutical development, a favourable property in the mitigation of drug resistance. We believe that a tight interplay between target-based computational approaches and experimental methods will result in the development of original inhibitors that could serve as the basis of a new generation of drugs against tuberculosis.