Isolation of 5,7-Dihydroxy, 6,8-Dimethyl Flavanone from Syzygium aqueum with Its Antioxidant and Xanthine Oxidase Inhibitor Activities

Muhamad Insanu; Zelika Mega Ramadhania; Evelyne Nadia Halim; Rika Hartati; Komar Ruslan Wirasutisna

doi:10.4103/pr.pr_59_17

Isolation of 5,7-Dihydroxy, 6,8-Dimethyl Flavanone from Syzygium aqueum with Its Antioxidant and Xanthine Oxidase Inhibitor Activities

Pharmacognosy Res. 2018 Jan-Mar;10(1):60-63. doi: 10.4103/pr.pr_59_17.

Authors

Muhamad Insanu¹, Zelika Mega Ramadhania², Evelyne Nadia Halim¹, Rika Hartati¹, Komar Ruslan Wirasutisna¹

Affiliations

¹ Department of Pharmaceutical Biology, School of Pharmacy, Institut Teknologi Bandung, Bandung, West Java, Indonesia.
² Department of Pharmaceutical of Biology, Faculty of Pharmacy, Universitas Padjadjaran, Bandung, West Java, Indonesia.

Abstract

Background: Syzygium aqueum Burm.f. Alston (water apple) belonging to Myrtaceae family was originated from tropical areas. It was traditionally used as a medicinal plant.

Objective: The objective of the study was to isolate the active compound from the methanolic extract of S. aqueum leaves.

Methods: Extraction was done using continuous extraction with methanol as a solvent. The extract was then fractionated using liquid-liquid extraction, vacuum liquid chromatography, and radial chromatography. Recrystallization was done for purification. The structure of the compound was determined by Ultraviolet-Visible and (1D and 2D) nuclear magnetic resonance (NMR) spectrometer.

Results: The isolate showed maximum wavelengths at 347 (band I) and 296 (band II) nm. After addition of NaOH and CH₃ COONa, the maximum wavelengths of band II moved to 340 and 339 nm, respectively. There was no change in wavelengths after addition CH₃ COONa/H₃ BO₃ and AlCl₃. The ¹H-NMR spectrum showed 16 protons, whereas ¹³C-NMR spectrum showed 15 carbons. Based on those data, the isolate was determined as 5,7-dihydroxy-6,8-dimethyl flavanone (demethoxymatteucinol). At a concentration of 100 and 50 μg/mL, it could inhibit 25.13% of xanthine oxidase (XO) activity and scavenge 11.87% of diphenyl-picrylhydrazyl, respectively.

Conclusion: Demethoxymatteucinol was isolated for the first time from S. aqueum and it had mild antioxidant and XO inhibitory activities.

Summary: One flavonoid compound, which 5,7-dihydroxy 6,8-dimethyl flavanone (demethoxymatteucinol), was isolated from the methanol extract of Syzygium aqueum. It had mild antioxidant and xanthine oxidase inhibitory activities. Abbreviations Used: CH₃ COONa/H₃ BO₃: Natrium acetate/Boric acid; DPPH: Diphenyl-picrylhydrazyl, NMR: Nuclear Magnetic Resonance; ABTS: 2,2'-azinobis (3-ethyl-benzothiazline-6-sulfonic acid); AEAC: Ascorbic Acid Equivalent Antioxidant Capacity; UV-Vis: Ultraviolet-Visible; XO: Xanthine Oxidase; HSQC: Heteronuclear Single Quantum Coherence; HMBC: (Heteronuclear Multiple Bond Correlation).

Keywords: Antioxidant; Myrtaceae; Syzygium aqueum; flavonoid.