title: A systematic review on biological activities of prenylated flavonoids.
abstract: BACKGROUND
  Prenylated flavonoids are a unique class of naturally occurring flavonoids that exist especially for the plant's self-defensive strategy. This special class of flavonoids increases the bioactivities of their backbone flavonoids with non-prenylation; therefore, prenylated flavonoids have more potential to be developed and utilized.
  
  
  OBJECTIVE
  The number, position and type of the prenyl group on the flavonoids backbone structure may have close relationships with the bioactivities of flavonoids.
  
  
  METHODS
  PubMed and WEB OF KNOWLEDGE® were used to search articles published in English between 1 January 2002 and 31 December 2012, which discuss the structure-activity relationship between prenylated flavonoids and their bioactivities.
  
  
  RESULTS
  It is proposed that the prenyl-moiety makes the backbone compound more lipophilic, which leads to its high affinity with cell membranes. The prenylation brings the flavonoids with enhancement of antibacterial, anti-inflammatory, antioxidant, cytotoxicity, larvicidal as well as estrogenic activities. However, it is reported that the prenyl-moiety decreases the bioavailability and plasma absorption of prenylated flavonoids.
  
  
  CONCLUSIONS
  The prenyl group affects the bioactivities of flavonoids in certain ways, while the action mechanisms and the structure-activity relationship as well as more in vivo studies even clinical validation trials need to be further investigated.
authors.affiliation: School of Medical Instrument and Food Engineering, Center for Systems Biomedical Sciences, University of Shanghai for Science and Technology , Shanghai 200093 , People's Republic of China .
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mukwaya
authors.forename: Man-Sau
authors.initials: MS
authors.lastname: Wong
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002460:Cell Line; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D015394:Molecular Structure; D028321:Plant Preparations / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D054876:Prenylation; D013329:Structure-Activity Relationship
chemical_list: D005419:Flavonoids; D028321:Plant Preparations