Details

Autor(en) / Beteiligte

• Popov, Sergey A.
• Wang, Chengzhang
• Qi, Zhiwen
• Shults, Elvira E.
• Turks, Māris

Titel

Synthesis of water-soluble ester-linked ursolic acid-gallic acid hybrids with various hydrolytic stabilities

Ist Teil von

• Synthetic communications, 2021-08, Vol.51 (16), p.2466-2477

Ort / Verlag

Philadelphia: Taylor & Francis

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• To obtain derivatives of ursolic acid with improved water solubility and antioxidant activity, new ester-linked hybrids of ursolic acid and gallic acid were synthesized. In the reaction of methyl gallate with ursoloyl chloride acetate, both mono- and diacylation products were obtained. To prepare mono-alkylated and mono-acylated derivatives of gallic acid, 4,5-O-methoxymethylene-protected methyl gallate was used. It was found that ursolic-gallic acid hybrids containing phenolic ester linkage readily underwent hydrolysis at C-28 of triterpenoid. The dioxolane protection allowed selective hydrolysis of the methyl ester at the aromatic moiety of the hybrid compound leaving intact the labile C-28 ester at the triterpenoid moiety. The hybrids possessing an ester-ether linker (terpenoid-COO-CH 2 CH 2 -O-aryl) are stable to the hydrolysis. The majority of the obtained ursolic-gallic acid hybrids containing free phenolic hydroxyl groups possess excellent antioxidant activity. Notable water solubilities (∼0.5 mg/mL) of novel hybrids containing both carboxyl group and hydroxyls at aromatic moiety were found.