Chemical properties and inhibitory activities of tyrosinase, α‐glucosidase, and urease from chloroform extract of Curcuma aromatica Salisb. rhizomes

Abstract "Nghệ trắng" has the scientific name of Curcuma aromatica Salisb., belongs to the Ginger family (Zingiberaceae), and its rhizomes are used to prevent aging, anti‐inflammatory, and improve skin. From the chloroform extract of C. aromatica , six known compounds, including (‐)‐hannokinol ( 1 ), (3 R ,5 R )‐3,5‐diacetoxy‐1,7‐bis(4‐hydroxyphenyl)heptane ( 2 ), naringenin ( 3 ), 2‐(4‐(hydroxymethyl)phenyl)propan‐2‐ol ( 4 ), 5‐hydroxymethylfurfural ( 5) , and bisacurone ( 6 ), were isolated. Structures of all compounds were elucidated by analyzing NMR data together with comparing them to references. All isolated compounds were found for the first time in the C. aromatia rhizomes grown in Vietnam. The results of bioactivity evaluation showed that naringenin ( 3 ) has an effect against tyrosinase and α ‐glucosidase with the IC 50 values of 96.4 and 248.2 μ M, respectively. (‐)‐Hannokinol ( 1 ) is a moderate bioactivity ingredient capable to inhibiting α ‐glucosidase and urease with the IC 50 value of 216.4 and 244.4 μ M, respectively. Consequently, these results suggest that chloroform extract of C. aromatica may be a practical therapeutic approach for diabetes, melanogenesis, and stomach ulcer treatment.