Syntheses and antibacterial activities of 4 linear nonphenolic diarylheptanoids

Four linear nonphenolic diarylheptanoids were synthesized and their antibacterial activities were studied. ( )-2-Me-CBS-catalysed reduction of alnustone with BH SMe gave ( )(-)(4 ,6 )-1,7-diphenylhepta-4,6-dien-3-ol, a natural product. Reduction of alnustone with Na in -BuOH at -15 °C under N atm gave ( )-1,7-diphenylhept-5- en-3-one as a Birch-type reduction product. -BuOK catalysed condensation of benzalacetone with propionyl chloride gave (4 ,6 )-5-hydroxy-1,7-diphenylhepta-4,6-dien-3-one, a natural product. (1 ,4 ,6 )-5-Hydroxy-4-phenethyl-1,7-diphenylhepta-1,4,6-trien-3-one, a curcuminoid, was synthesized starting from pentan-2,4-dione in 3 steps. The synthesized chemical compounds were applied against 2 gram-positive bacteria ( and ), 4 gram-negative bacteria ( , , , and ), and 1 yeast (Candida albicans) by the disc diffusion method. All of the synthesized compound exhibited different degrees of antimicrobial activity at concentrations between 20-100 μg/disc against the test organisms.