ADMET analysis of ligand(s)
Lipinski’s rule of 5 describes the drugability of a determinate molecules.It helps to determine if a biologically active chemical is likely to have the chemical and physical properties to be orally bioavailable.The Lipinski’s rule bases pharmacokinetic properties such as absorption, distribution, metabolism,and excretion on specific molecular properties such as
a)No more than 5 hydrogen bond donors
b)No more than 10 hydrogen bond acceptors
c)Molecular mass less than 500 Da
d) Partition co-efficient not greater than 5.
The violation of 2 or more of these conditions predicts a molecule as a non orally available drug.
The druglikeness of 11 phytocompounds of Achyranthes aspera is shown in table1. The compound 3,5,6,8,10 and 11 have molecular weight MW<500 Da. Next criteria of RO5< is the number of H bond donor(0-5) and number of H bond acceptor(0-10).Except the compounds 1,6 and 10 ,all the compounds belong to this range. For the forecast of oral liability of drug molecules, Lipophilicity(LogP) and Topological polar surface area(TPSA) values are crucial.Most of the compounds LogP ranges from (0.10-5),which is acceptable limits for drug to penetrate biomembrane.The ADMET analysis of phytocompounds are shown in table2.
Table 1 Pharmacokinetics properties of natural compounds according to Lipinski rule analysis for A. aspera plant
Sl. No.
|
Compound name
|
M.W. (g/mol)
|
No. of H bond acceptors
|
No. of H bond donor
|
logP
|
RO5
|
1
|
6-[[9-Acetyloxy-8-hydroxy-4,8a-bis(hydroxymethyl)-4,6a,6b,11,11,14b-hexamethyl-10-(2-methylbut-2-enoyloxy)-1,2,3,4a,5,6,7,8,9,10,12,12a,14,14a-tetradecahydropicen-3-yl]oxy]-4-hydroxy-3,5-bis[[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy]oxane-2-carboxylic acid
|
1131.269
|
24
|
13
|
0.105
|
NO
|
2
|
2,3,14,20,25-Pentahydroxy-6-oxocholest-7-en-22-yl benzoate
|
584.75
|
8
|
5
|
3.78
|
yes
|
3
|
Cocamidopropyl betaine
|
342.52
|
3
|
1
|
-2.247
|
yes
|
4
|
14-Hydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-2,6,6,18-tetramethyl-5,7-dioxapentacyclo[11.7.0.02,10.04,8.014,18]icos-12-en-11-one
|
560.77
|
7
|
2
|
5.141
|
yes
|
5
|
Phenylalanine betaine
|
117.148
|
3
|
1
|
-5.412
|
yes
|
6
|
Betaine monohydrate
|
117.148
|
7
|
6
|
-4.838
|
yes
|
7
|
2,3,14-trihydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
520.707
|
7
|
4
|
3.25
|
yes
|
8
|
Cloral betaine
|
117.148
|
4
|
2
|
-5.412
|
yes
|
9
|
Ecdysterone 2,3-acetonide 22-O-benzoate
|
624.81
|
8
|
3
|
5.678
|
yes
|
10
|
2,3,14-trihydroxy-10,13-dimethyl-17-(2,4,7-trihydroxy-6-methylheptan-2-yl)-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
480.642
|
7
|
6
|
1.296
|
yes
|
11
|
2,3,14,20,22,25-Hexahydroxycholest-7-en-6-one
|
480.642
|
2
|
0
|
1.359
|
yes
|
Table 2 ADMET properties of natural compounds for A. aspera plant
Sl. No.
|
Compound name
|
miLogp
|
TPSA
|
natoms
|
nrotB
|
nVio
|
1
|
6-[[9-Acetyloxy-8-hydroxy-4,8a-bis(hydroxymethyl)-4,6a,6b,11,11,14b-hexamethyl-10-(2-methylbut-2-enoyloxy)-1,2,3,4a,5,6,7,8,9,10,12,12a,14,14a-tetradecahydropicen-3-yl]oxy]-4-hydroxy-3,5-bis[[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy]oxane-2-carboxylic acid
|
0.105
|
388.049
|
79
|
16
|
3
|
2
|
2,3,14,20,25-Pentahydroxy-6-oxocholest-7-en-22-yl benzoate
|
3.78
|
144.51
|
42
|
8
|
1
|
3
|
Cocamidopropyl betaine
|
-2.24
|
69.22
|
24
|
17
|
0
|
4
|
14-Hydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-2,6,6,18-tetramethyl-5,7-dioxapentacyclo[11.7.0.02,10.04,8.014,18]icos-12-en-11-one
|
5.141
|
94.463
|
40
|
4
|
1
|
5
|
Phenylalanine betaine
|
-5.412
|
40.128
|
8
|
2
|
0
|
6
|
Betaine monohydrate
|
-4.83
|
40.128
|
15
|
5
|
1
|
7
|
2,3,14-trihydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
3.25
|
116.451
|
37
|
4
|
1
|
8
|
Cloral betaine
|
-5.412
|
40.128
|
8
|
3
|
0
|
9
|
Ecdysterone 2,3-acetonide 22-O-benzoate
|
5.678
|
122.528
|
45
|
8
|
1
|
10
|
2,3,14-trihydroxy-10,13-dimethyl-17-(2,4,7-trihydroxy-6-methylheptan-2-yl)-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
1.296
|
138.439
|
34
|
6
|
1
|
11
|
2,3,14,20,22,25-Hexahydroxycholest-7-en-6-one
|
1.359
|
138.439
|
34
|
4
|
0
|
*TPSA, Topological Polar Surface Area; natoms, number of atoms; nrotB, number of rotatable bonds; nVio, number of Violations
Bioactivity score prediction
The bioactivity or biological activity means the beneficial or adverse effects of a drug on living tissue.It suggests the uses of the phytocompounds in the medical applications. Molecules having bioactivity score more than 0.00 is most likely to exhibit considerable biological activity. If the values ranges from 0.50 to 0.00, are moderately active and if the score is less than 0.50, then it is inactive. Molinspiration tool was used to predict bioactivity score of phytocompounds against human receptors such as GPCRs, ION CHANNEL, KINASE, NUCLEAR RECEPTORS, PROTEASES and ENZYMES, which is shown in the table3.The results shows that except compounds 1,6,8,9 the other compounds are active against GPCR ligands.
Oral toxicity prediction
The prediction of compound toxicities is an important part of drug design development process. ProTox-II is a virtual lab for the prediction of toxicities of small molecules. Toxic doses are often given ad LD50 values in mg/kg body weight.The LD50 is the median lethal dose meaning the dose at which 50% of the test subjects die upon exposure to a compound.Toxicity classes are defined according to LD50
Class1: Fatal if swallowed(LD50<5)
Class2: Fatal if swallowed(5<LD50<50)
Class3:Toxic if swallowed(50<LD50<300)
Class4:Harmful if swallowed(300<LD50<2000)
Class5: May be harmful if swallowed(2000<LD50<5000)
Class6: Non toxic(LD50>5000)
The oral toxicity of these phytocompounds is shown in table4.
Table 3 Bioactivity Score of natural compounds for A. aspera plant
Sl. No.
|
Compound name
|
GPCR L
|
Ion CM
|
Kinase INH
|
Nuclear RL
|
Protease INH
|
Enzyme INH
|
|
Ion CM
|
Kinase INH
|
Nuclear RL
|
Protease INH
|
Enzyme INH
|
1
|
6-[[9-Acetyloxy-8-hydroxy-4,8a-bis(hydroxymethyl)-4,6a,6b,11,11,14b-hexamethyl-10-(2-methylbut-2-enoyloxy)-1,2,3,4a,5,6,7,8,9,10,12,12a,14,14a-tetradecahydropicen-3-yl]oxy]-4-hydroxy-3,5-bis[[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy]oxane-2-carboxylic acid
|
-3.77
|
-3.85
|
-3.89
|
-3.78
|
-3.72
|
-3.71
|
2
|
2,3,14,20,25-
Pentahydroxy-6-oxocholes
t-7-en-22-yl benzoate
|
0.02
|
-0.30
|
-0.47
|
0.49
|
0.15
|
0.36
|
3
|
Cocamidopropyl betaine
|
0.34
|
0.32
|
-0.20
|
-0.58
|
0.04
|
0.33
|
4
|
14-Hydroxy-17-[5-(3-hydroxy
-3-methylbutyl)-2,2,4-trimethy
l-1,3-dioxolan-4-yl]-2,6,6,18-
tetramethyl-5,7-dioxapentacyclo[11.7.0.02,10.04,
8.014,18]icos-12-en-11-one
|
0.02
|
-0.20
|
-0.44
|
0.73
|
0.13
|
0.40
|
5
|
Phenylalanine betaine
|
0.01
|
0.30
|
-0.55
|
-1.00
|
-0.46
|
0.04
|
6
|
Betaine monohydrate
|
-2.53
|
-1.79
|
-3.50
|
-3.75
|
-3.47
|
-2.12
|
7
|
2,3,14-trihydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
0.09
|
-0.04
|
-0.36
|
0.87
|
0.25
|
0.59
|
8
|
Cloral betaine
|
-2.53
|
-1.79
|
-3.50
|
-3.75
|
-3.47
|
-2.12
|
9
|
Ecdysterone 2,3-acetonide 22-O-benzoate
|
-0.24
|
-0.70
|
-0.77
|
0.23
|
-0.00
|
0.07
|
10
|
2,3,14-trihydroxy-10,13-dimethyl-17-(2,4,7-trihydroxy-6-methylheptan-2-yl)-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
0.11
|
0.07
|
-0.43
|
0.79
|
0.19
|
0.63
|
11
|
2,3,14,20,22,25-Hexahydroxycholest-7-en-6-one
|
0.16
|
0.17
|
-0.32
|
0.92
|
0.32
|
0.68
|
*GPCRL, G-Protein Coupled Receptor Ligand; Ion CM, Ion channel Modulator; Kinase INB, Kinase inhibitor; Nuclear RL, Nuclear receptor ligand; Protease INH, Protease inhibitor; Enzyme INH, Enzyme inhibitor
Table 4 Oral toxicity prediction of natural compounds for A. aspera plant
Sl.No.
|
Compound name
|
|
Toxic. Class (1-6)
|
Avg. SM
|
Pred. AC (%)
|
1
|
6-[[9-Acetyloxy-8-hydroxy-4,8a-bis(hydroxymethyl)-4,6a,6b,11,11,14b-hexamethyl-10-(2-methylbut-2-enoyloxy)-1,2,3,4a,5,6,7,8,9,10,12,12a,14,14a-tetradecahydropicen-3-yl]oxy]-4-hydroxy-3,5-bis[[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy]oxane-2-carboxylic acid
|
134
|
3
|
100
|
100
|
2
|
2,3,14,20,25-
Pentahydroxy-6-oxocholes
t-7-en-22-yl benzoate
|
2450
|
5
|
59.85
|
67.38
|
3
|
Cocamidopropyl betaine
|
400
|
4
|
76.42
|
69.26
|
4
|
14-Hydroxy-17-[5-(3-hydroxy
-3-methylbutyl)-2,2,4-trimethy
l-1,3-dioxolan-4-yl]-2,6,6,18-
tetramethyl-5,7-dioxapentacyclo[11.7.0.02,10.04,
8.014,18]icos-12-en-11-one
|
4500
|
4
|
70.79
|
69.26
|
5
|
Phenylalanine betaine
|
1100
|
4
|
70.87
|
69.26
|
6
|
Betaine monohydrate
|
650
|
4
|
100
|
100
|
7
|
2,3,14-trihydroxy-17-[5-(3-hydroxy-3-methylbutyl)-2,2,4-trimethyl-1,3-dioxolan-4-yl]-10,13-dimethyl-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
4500
|
4
|
71.59
|
69.26
|
8
|
Cloral betaine
|
800
|
4
|
70
|
68.07
|
9
|
Ecdysterone 2,3-acetonide 22-O-benzoate
|
1750
|
4
|
57.19
|
67.38
|
10
|
2,3,14-trihydroxy-10,13-dimethyl-17-(2,4,7-trihydroxy-6-methylheptan-2-yl)-2,3,4,5,9,11,12,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-6-one
|
9000
|
6
|
97.96
|
72.9
|
11
|
2,3,14,20,22,25-Hexahydroxycholest-7-en-6-one
|
9000
|
6
|
100
|
100
|
*LD50, Lethal dose 50%; Toxic, Class- toxicity class; Avg. SM, Average similarity; Prediction accuracy
Molecular docking
The molecular docking analysis of all 11 natural compounds of A. aspera plant accompanied by the flexible or blind docking method. The selected target proteins 3-dehyroquinate synthase (3N76) and 3-dehydroquinate dehydratase(3qbe) is docked with selected ligands from the plant compounds Achyranthes aspera using the AutoDock Vina software. Theresults exhibit different binding affinities of the target protein 3-dehydroquinate synthase and 3dehydroquinate dehydratase with the inhibitors. Finally 6 best results were selected primarily based on Lipinski’s rules and observing the 3D interactions.From the docking study, the compound9(Ecdysterone 2,3-acetonide 22-O-benzoate), has highest binding affinity with enzyme 3-dehydroquinate synthase(3N76), And the compound 2(2,3,14,20,25-Pentahydroxy-6-oxocholest-7-en-22-yl benzoate) has highest binding affinity with enzyme 3-dehydroquinate dehydratase(3QBE) is shown in table5.
Table 5 Ligand-receptor interaction of natural compounds which has highest binding affinity with M. tuberculosis 3N76 and 3QBE proteins.
Sl.No.
|
PDB ID
|
Binding affinity( Kcal/mol)
|
|
|
Lig 2
|
Lig4
|
Lig7
|
Lig10
|
Lig11
|
Lig9
|
1
|
3N76
|
-
|
-
|
-6.2
|
-
|
-
|
-6.7
|
2
|
3QBE
|
-10.1
|
-8.8
|
-9.7
|
-9
|
-8.9
|
-
|
* Lig, ligand number; PDB ID, Protein Data Bank ID
BOILED EGG ANALYSIS
The boiled egg analysis evaluates the gastrointestinal absorption (HIA) and brain penetration(BBB) in function of the position of the molecules in the WLOGP versus –TPSA referential.The white region means the high probability of passive gastrointestinal absorption ang yellow portion means the high probability of brain penetration. The points are coloured in blue if predicted as actively effluxed by P-gp(PGP+) and in red if predicted as non substrate of P-gp(PGP-). The boiled egg analysis of compound 2 and compound 9 was done. These two molecules are predicted as not absorbed and not brain penetrant(outside the egg), but PGP+. The boiled egg analysis of these compounds are shown in figure 1.
Visualization of the protein-ligand interaction
From the docking study, the compound9(Ecdysterone 2,3-acetonide 22-O-benzoate), has highest binding affinity with enzyme 3-dehydroquinate synthase(3N76), And the compound 2(2,3,14,20,25-Pentahydroxy-6-oxocholest-7-en-22-yl benzoate) has highest binding affinity with enzyme 3-dehydroquinate dehydratase(3QBE).The binding interaction between receptors and ligands are visualiZed by PyMOL software.The molecular docking results suggested that seven amino acids may be important in the interaction between DHQs and compound9 which is shown in table6.The results showed that Ile 125, val 124, pro119, His 114, ser 118, His 106, val 105 are essential for function of mtDHQs. We speculated that compound 9 binds to the active center of DHQs and inhibits its catalytic activity.The interaction of compound9 with enzymeDHQ is shown in figure2.The interaction between compound2 and 3-dehydroquinate dehydratase is analyzed by molecular docking. The molecular docking results suggest that 12 amino acids may be important in the interaction between DHQase and compound2. The results showed that trp263, glu256, asn154, leu134, glu179, cys182, gly107, ala108, ala139, His265, lys228 are essential for function of mtDHQase. The interaction is shown in figure3.
Table 6 Ligand-receptor interaction with group involved in interaction of the receptor
Sl.No.
|
PDB ID
|
Ligands
|
Amino acids involved with interactive group
|
1
|
3N76
|
ligand 9
|
Ile 125
val 124
pro119
His 114
ser 118
His 106
val 105
|
2
|
3QBE
|
Ligand 2
|
asn154
lys228
glu75
trp263
|