Phenolic metabolites, biological activities, and isolated compounds of Terminalia muelleri extract

Figures & data

Table 1. ¹³C NMR data of compounds 1 and 2 in DMSO-d₆ at 125 MHz.

Atom no.	1	2
Aglycone moiety
2	164.02	164.14
3	102.39	102.35
4	181.96	181.88
5	161.17	160.55
6	97.68	97.67
7	162.05	162.07
8	103.82	103.81
9	156.39	156.40
10	102.47	102.42
1′	121.60	122.01
2′	129.02	114.06
3′	115.85	145.83
4′	160.55	149.66
5′	115.85	115.71
6′	129.02	119.46
Glucose moiety
1″	71.07	71.12
2″	72.24	72.22
3″	75.97	76.10
4″	70.56	70.80
5″	82.01	82.18
6″	60.97	61.36
Galloyl moiety
1‴	119.34	119.41
2‴,6‴	108.53	108.57
3‴,5‴	145.22	145.22
4‴	138.14	138.13
7‴	164.79	164.78

Figure 1. Chemical structures of isolated compounds of Terminalia muelleri.

Figure 2. [GRAPHIC] HMBC correlations for 1 and 2. [GRAPHIC] Cosy correlations for H-2″ and H-1″ & 3″.

Table 2. DPPH radical scavenging activity of the total extract and the isolated compounds.

Compound	DPPH free radical scavengingactivity IC50^a (µg/mL)
Alcoholic extract	3.55 ± 0.20
Compound 1	150.02 ± 2.84
Compound 2	56.32 ± 1.86
Compound 3	198.56 ± 2.68
Compound 4	189.42 ± 2.58
Compound 5	146.24 ± 2.43
Compound 6	126.05 ± 1.89
Compound 7	158.46 ± 2.34
Compound 8	118.62 ± 1.98
Compound 9	67.54 ± 1.86
Compound 10	6.34 ± 0.18
Ascorbic acid	40.20 ± 0.40

^a Values of IC₅₀ were calculated as the mean of triplicate determinations ± standard deviation, concentrations in µg/mL required scavenging the DPPH radical (100 μg/mL) by 50%.

Figure 3. The correlations between different concentrations of the total extract of T. muelleri and the surviving fraction of MCF-7 and PC3 cancer cells.

Figure 4. The correlations between different concentrations of compound 1 of T. muelleri and the surviving fraction of MCF-7 and PC3 cancer cells.

Figure 5. The correlations between different concentrations of compound 1 of T. muelleri and the surviving fraction of MCF-7 and PC3 cancer cells.

Figure 6. Ligand interaction representation of compounds 1 and 2 of T. muelleri with human topo I–DNA complex.

Figure 7. Ligand interaction representation (left) of camptothecin with human topo I–DNA complex and the corresponding 3D form (right).

Figure 8. 3D representation of compounds 1 and 2 of T. muelleri with human topo I–DNA complex.

Table 3. Binding scores and amino acid interactions of the docked compounds on the active site of human DNA topoisomerase I enzyme (PDB: 1T8I).

Cpds	RMSD	E-refine	Active site interaction	Interaction type	Distance
Camptothecin	0.782	–20.03
1	1.697	–28.64	ASN 722	H-donor	3.28
			LYS 436	H-acceptor	2.94
			DT 10	pi–pi	3.90
			TGP 11	pi–pi	3.91
			TGP 11	pi–pi	3.73
2	1.5249	–30.81	LEU 429	H-donor	2.89
			TGP 11	H-donor	2.65
			ILE 424	H-donor	3.20
			LYS 425	H-acceptor	3.21
			MET 428	H-acceptor	2.81