- Phytotoxins from Hofmeisteria schaffneri: Isolation and synthesis of 2′-(2″-hydroxy-4″-methylphenyl)-2′-oxoethyl acetate
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Activity-directed fractionation of a CH2Cl2-MeOH (1:1) extract of Hofmeisteria schaffneri led to the isolation of a new phytotoxin characterized as 2′-(2″-hydroxy-4″-methylphenyl)- 2′-oxoethyl acetate and designated the trivial name of hofmeisterin (1). In addition, the known compounds β-carotene, euparin, and 3′,4′,4a′,9a′-tetrahydro-6,7′- dimethylspiro[benzofuran-3(2H),2′-pyrano[2,3-b]benzofuran]-2, 4a′-diol (2) were obtained. The identification of the isolates was accomplished by spectroscopic methods. The structure of 1 was unequivocally confirmed by synthesis. The methyl derivative 1a was also synthesized following the same strategy. Compounds 1 and 2 inhibited radicle growth of Amaranthus hypochondriacus (IC50 = 3.2 × 10-4 and 1.2 × 10-5 M, respectively) and significantly inhibited activation of the calmodulin (CaM)-dependent enzyme cAMP phosphodiesterase (PDE) with IC 50 values of 4.4 and 4.22 μM, respectively.
- Perez-Vasquez, Araceli,Reyes, Adelfo,Linares, Edelmira,Bye, Robert,Mata, Rachel
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p. 959 - 962
(2008/12/22)
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