TY  - JOUR
A1  - Kwesiga, George
A1  - Kelling, Alexandra
A1  - Kersting, Sebastian
A1  - Sperlich, Eric
A1  - von Nickisch-Rosenegk, Markus
A1  - Schmidt, Bernd
T1  - Total syntheses of prenylated isoflavones from Erythrina sacleuxii and their antibacterial activity
T2  - Journal of natural products
N2  - The prenylated isoflavones 5-deoxyprenylbiochanin A (7-hydroxy-4'-methoxy-3'-prenylisoflavone) and erysubin F (7,4'-dihydroxy-8,3'-diprenylisoflavone) were synthesized for the first time, starting from mono-or di-O-allylated chalcones, and the structure of 5-deoxy-3'-prenylbiochanin A was corroborated by single-crystal X-ray diffraction analysis. Flavanones are key intermediates in the synthesis. Their reaction with hypervalent iodine reagents affords isoflavones via a 2,3-oxidative rearrangement and the corresponding flavone isomers via 2,3-dehydrogenation. This enabled a synthesis of 7,4'-dihydroxy-8,3'-diprenylflavone, a non-natural regioisomer of erysubin F. Erysubin F (8), 7,4'-dihydroxy-8,3'-diprenylflavone (27), and 5-deoxy-3'prenylbiochanin A (7) were tested against three bacterial strains and one fungal pathogen. All three compounds are inactive against Salmonella enterica subsp. enterica (NCTC 13349), Escherichia coli (ATCC 25922), and Candida albicans (ATCC 90028), with MIC values greater than 80.0 mu M. The diprenylated natural product erysubin F (8) and its flavone isomer 7,4'-dihydroxy-8,3'diprenylflavone (27) show in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA, ATCC 43300) at MIC values of 15.4 and 20.5 mu M, respectively. In contrast, the monoprenylated 5-deoxy-3'-prenylbiochanin A (7) is inactive against this MRSA strain.
Y1  - 2020
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/58562
SN  - 0163-3864
SN  - 1520-6025
VL  - 83
IS  - 11
SP  - 3445
EP  - 3453
PB  - American Chemical Society
CY  - Washington
ER  -