Title
Propolis Components from Stingless Bees Collected on South Sulawesi, Indonesia, and Their Xanthine Oxidase Inhibitory Activity
Author
Ryo Miyata, Muhamad Sahlan, Yoshinobu Ishikawa, Hiroshi Hashimoto, Sari Honda, Shigenori Kumazawa
Year
2019
Journal
Journal of Natural Products
Abstract
Three new compounds, namely, 4-(4′-hydroxy-3′-methoxyphenyl)-3,5,7-trihydroxycoumarin (1) and sulawesins A (2) and B (3), were isolated from the propolis of stingless bees (Tetragonula aff. biroi) collected on South Sulawesi, Indonesia. In addition, five known compounds, glyasperin A, broussoflavonol F, (2S)-5,7-dihydroxy-4′-methoxy-8-prenylflavanone, (1′S)-2-trans,4-trans-abscisic acid, and (1′S)-2-cis,4-trans-abscisic acid, were identified. The structures of the new compounds were determined by a combination of methods that included mass spectrometry and NMR spectroscopy. The absolute configuration of sulawesin A (2), a new podophyllotoxin derivative, was determined by X-ray crystallography. The absolute configuration of sulawesin B (3) was also determined by the ECD calculation. 4-(4′-Hydroxy-3′-methoxyphenyl)-3,5,7-trihydroxycoumarin (1) and sulawesin A (2) were examined for xanthine oxidase (XO) inhibitory activity; 1 exhibited XO inhibitory activity, with an IC50 value of 3.9 μM.
Instrument
J-820
Keywords
Circular dichroism, Cotton effect, Absolute configuration, Natural products, Pharmaceutical