Aldose reductase and protein tyrosine phosphatase 1B inhibitory active compounds from Syzygium cumini seeds

Figures & data

Figure 1. Bioactivity guided fractionation of the methanolic extract of S. cumini seeds.

Figure 2. Molecular structures of six isolated compounds.

Figure 3. Representative chromatograms of (A) standard mixture and (B) methanolic extract of S. cumini seeds.

Table 1. The inhibitory activity of extracts and isolated compounds 1–6 from S. cumini seeds against AR and PTP1B.

	(IC50, µg/mL)^a
Extract/compounds	AR (mean ± SEM)	PTP1B (mean ± SEM)
MeOH extract^b	3.32 ± 0.25	38.21 ± 0.115
EtOAc extract^b	2.50 ± 0.091	26.36 ± 0.475
n-BuOH extract^b	2.04 ± 0.22	>100
Aqueous extract^b	17.52 ± 1.15	NA
Maslinic acid (1)	NA	>100
5-Hydroxymethylfurfuraldehyde (2)	NA	>100
Gallic acid (3)	0.77 ± 0.036	NA
Valoneic acid dilactone (4)	0.075 ± 0.005	9.37 ± 0.74
Rubuphenol (5)	0.165 ± 0.035	28.14 ± 6.91
Ellagic acid (6)	0.12 ± 0.019	25.96 ± 0.22
Quercetrin^c	0.70 ± 0.10	–
Bakuchiol^c	–	49.98 ± 0.47

NA, not active up to 100 μg/mL.

^aIC₅₀ values were determined by in vitro aldose reductase and PTP1B inhibitory assays.

^bμg/mL.

^cPositive controls.