Anti-HIV-1 integrase activity and molecular docking of compounds from Albizia procera bark

Figures & data

Figure 1. Structures of compounds 1 and 2 isolated from Albizia procera bark.

Table 1. IC₅₀ values^a of the extract and fractions of Albizia procera against HIV-1 IN activity.

Sample	IC50 (µg/mL)
Ethanol extract	19.5 ± 0.9
Hexane fraction	>100
Chloroform fraction	>100
Ethyl acetate fraction	19.1 ± 1.1
Water fraction	21.3 ± 0.9
Suramin (positive control)	10.0 ± 0.8

^aEach value represents mean ± S.E.M. of four determinations.

Table 2. % Inhibition^a and IC₅₀ values of isolated compounds from ethyl acetate fraction of Albizia procera against HIV-1 IN activity.

	% Inhibition at various concentrations (µM)
Compound	3	10	30	100	IC50 (µM)
(+)-Catechin (1)	–	31.2 ± 0.6	34.2 ± 0.9	66.2 ± 1.4	46.3 ± 0.5
Protocatechuic acid (2)	–	31.9 ± 2.4	36.4 ± 1.9	46.0 ± 1.1	>100
Suramin (positive control)	29.0 ± 2.9	60.4 ± 1.7	82.4 ± 1.3	83.1 ± 0.7	7.0 ± 0.8

^aEach value represents mean ± S.E.M. of four determinations.

Figure 2. Molecular docking of (+)-catechin (1) with HIV-1 IN. The ribbon model shows the backbone of HIV-1 IN catalytic domain with all interacting amino acid residues shown as stick models and colored by element. (+)-Catechin is shown pink stick model. H-bond interactions are shown as blue dash lines and represent bond length in angstrom (Å). Mg²⁺ ions are shown as red balls.

Figure 3. Molecular docking of protocatechuic acid (2) with HIV-1 IN. The ribbon model shows the backbone of HIV-1 IN catalytic domain with all interacting amino acid residues shown as stick models and colored by element. Protocatechuic acid is shown as yellow stick model. H-bond interactions are shown as blue dash lines and represent the bond length in angstrom (Å). Mg²⁺ ions are shown as red balls.

Table 3. Anti-HIV 1 IN activity and molecular docking study of pure compounds from Albizia procera bark.

			Amino acid residues with form H-bonding for each compound (distance: Å)
Compounds	Anti-HIV-1- Inactivity (IC50; µM)	Binding Energy (kcal/mol)	ASP64	THR66	HIS67	GLN148	GLU152	ASN155	LYS159
(+) Catechin (1)	46.3	−5.16 C = 1 F = 33	–	OG1- - -4′-H (1.88)	–	O- - -5-H (1.81) OE1- - -7-H (1.94)	O- - -3′-H (2.11)	–	–
Protocatechuic acid (2)	>100	−4.85 C = 2 F = 47	–	OG1- - -7-H (1.61) HG1- - -7-O (2.31)	HN- - -7-O (1.90)	–	O- - -3-H (2.21) O- - -4-H (2.31)	HD21- - -4-O (1.83)	HZ3- - -7-O (1.70)