Improved preparation of vitexin from hot water extract of Basella alba, the commercially available vegetable Malabar spinach ("Tsurumurasaki" in Japanese) and the application to semisynthesis of chafuroside B

Biosci Biotechnol Biochem. 2020 Aug;84(8):1554-1559. doi: 10.1080/09168451.2020.1761286. Epub 2020 Apr 30.


Hot water extraction of D-arabinofuranosylvitexin from the raw leaves of commercially available Basella alba "Tsurumurasaki" and subsequent acidic hydrolysis was improved to be a procedure using a high-pressure steam sterilizer to afford vitexin. The amount was estimated to be 14.1 mg from 1 g of dry weight of the raw leaves, whose recovery was calculated to be 95% based on the estimated content of D-arabinofuranosylvitexin in B. alba raw leaves. The product was dehydratively cyclized between hydroxy groups on the carbohydrate and flavone skeletons under modified Mitsunobu reaction conditions in N,N-dimethylformamide to give chafuroside B, which is known to be a bioactive Oolong tea polyphenol. Through these transformations, 10.2 mg of chafuroside B could be semisynthesized from 1 g of dry weight of the raw leaves, and the efficiency was improved compared to that from the extraction from Oolong tea (3.4 μg from 1 g of dry weight).

Keywords: C-glycosylated flavone; D-arabinofuranosylvitexin; hydrolysis.

MeSH terms

  • Apigenin / isolation & purification*
  • Caryophyllales / chemistry*
  • Dimethylformamide / chemistry
  • Flavones / chemical synthesis*
  • Flavones / chemistry
  • Heterocyclic Compounds, 4 or More Rings / chemical synthesis*
  • Hydrolysis
  • Liquid-Liquid Extraction / methods*
  • Plant Extracts / chemistry
  • Plant Leaves / chemistry*


  • 3,4,11-trihydroxy-2-(hydroxymethyl)-8-(4-hydroxyphenyl)-3,4,4a,11b-tetrahydro-2H,10H-pyrano(2',3'-4,5)furo(3,2-g)chromen-10-one
  • Flavones
  • Heterocyclic Compounds, 4 or More Rings
  • Plant Extracts
  • Apigenin
  • Dimethylformamide
  • vitexin