The growing demand for therapeutic strategy development and the discovery of competent drugs against COVID is essential in this pandemic. Consequently, the toxicity of these compounds was screened by the web server ADMETlab 2.0, and the properties were evaluated based on parameters like Absorption, Distribution, Metabolism, Excretion, and Toxicity. Regarding the physicochemical aspect, a few important parameters were considered vital in predicting efficient drug candidates against COVID-19 main protease. The detailed parameters are described in
Table 3. The toxicity profile of 2-Deoxy-D-glucose and its various forms was evaluated based on a few potential parameters: molecular weight, which is critical for controlled and systematic drug delivery. These compounds' molecular weight was considered because they are crucial in the medication and oral bioavailability [
31]. The result obtained from the analysis showed that the modified 2-Deoxy-D-glucose with the lowest molecular weight, i.e., 132.08 Da, may indicate rapid absorption and excretion rate compared to the other two compounds. Controlled and systematic delivery of low molecular weight drugs through brain barrier modulation prevented retinal degeneration and suppressed laser-induced choroidal neovascularisation in neurodegenerative conditions [
32]. In addition, logP of the modified 2-Deoxy-D-glucose was found to be within an optimal range from 0 to 3 while 2-Deoxy-D-glucose and Cypate 2-Deoxy-D-glucose were in the < 0 and > 3 range. According to the boundaries set by Lipinski’s Rule, no violation was found when the partition coefficient logP < 5 [
33]. The reduced bioavailability of the compound beyond these boundaries indicated poor absorption or permeation [
34]. Similarly, the solubility of the compound, indicated by the logS value, improved the absorption at high rates. Apart from derivative and parent forms, the modified version evolved as an active inhibitor and increased the adsorption rate. The number of hydrogen bond acceptors and donors within the threshold values was ≤ 10 and ≤ 5, respectively. Another competent aspect, such as HIA, acted as an indicator of oral bioavailability, which was required to determine the efficacy of any drug [
35].
Table 3 showed the efficacy of modified 2-Deoxy-D-glucose and concluded that the revised version was preferable to the other two. The HIA category is restricted from 0 to 1, whereas 0 to 0.3 resides in the excellent category, 0.3 to 0.7 belongs to the medium, and 0.7 to 1.0 belongs to the poor category [
36]. Similar to HIA, F
30% or human oral bioavailability by 30% was acted as a correlated factor and found to be within the moderate region, i.e., 0.513 for modified 2-Deoxy-D-glucose while the other two fell in the poor category (a range within 0-0.3: excellent; 0.3-0.7: medium; 0.7-1.0: poor). The fraction unbound in plasma, Fu, is a critical component for determining drug efficacy in drug pharmacokinetic studies because of its relation with unbound states which alter the cellular response [
37]. On the other hand, PPB may not significantly alter drug development strategy but must be considered during the analysis of pharmacokinetic profiles in
vivo conditions. The value of PPB ≤ 90% is considered a preferable category, while above 90% belongs to a poor level. The values were 6.58% of PPB in modified 2-Deoxy-D-glucose and 97.58% in Cypate. PPB has an influential impact on oral bioavailability/distribution and clearance of the drug. Earlier studies reported the consequence of high PPB on the antiviral activity of NVR 3-778, a sulfamoylbenzamide capsid assembly modulator [
38]. The clearance of a drug for a modified one was found to be maximum. The threshold value of clearance of a drug is set by five while more than it belongs to the favorable region and lesser to the low category [
39]. Subsequently, half-life or T
1/2 was related by clearance of the drug and was found to be within a moderate range for the molecules except for the derivative forms (0-0.3: excellent; 0.3-0.7: medium; 0.7-1.0: poor). The safety of these compounds was also evaluated, where both the parent and modified molecule had no mutagenic effect. However, the derivative molecule had a toxic effect. Similarly, the modified form's drug-induced liver injury or DILI effect was less than Cypate 2-Deoxy-D-glucose. A high level of DILI has serious clinical consequences that cause hepatotoxicity or acute liver failure and has been cited as one of the major reasons for drug removal from the market [
40,
41]. Thus, the modified 2-Deoxy-D-glucose had favorable ADMET parameters and could be considered a suitable drug candidate during the treatment of viral infection. Hence, by combining these parameters, the current findings indicated that the potentiality of 2-Deoxy-D-glucose was improved following structural modification. Thus, the modified forms have the potential to be used as a therapeutic strategy against virally infected cells by inhibiting or restricting energy production in viral cells. The in vivo study with the potential drug could be a game changer in the fight against pandemics like COVID.