TY  - UNPB
ID  - pittir7946
UR  - http://d-scholarship-dev.library.pitt.edu/7946/
A1  - Bajpai, Reena
TI  - MIXTURE SYNTHESIS AND SPECTROSCOPIC ANALYSIS OF THE PHYTOPHTHORA MATING HORMONE ALPHA 1 AND THE CORRESPONDING BIS-MTPA ESTERS
Y1  - 2010/09/28/
N2  - Phytophthora are parasitic fungi like species that attack the roots and stems of plants. Theheterothallic species of phytophthora consist of two mating types A1 and A2. A hormone alpha 1secreted by the A1 mating type induces the formation of sexual oospores in the A2 mating type. In 2005 by Ojika and coworkers reported the isolation and constitutional characterization of the hormone alpha 1. The absolute configuration of the hormone alpha 1 was later assigned by comparison ofthe hormonal activity of a synthetic sample with the natural sample. Assignment of absoluteconfiguration on the basis of hormonal activity can however be error prone because the activityof any particular sample will depend on its isomeric purity.In order to provide a spectroscopic method to assign the absolute configuration ofhormone alpha 1, we have synthesized eight stereoisomers of hormone alpha 1 by Fluorous MixtureSynthesis. During the FMS, stereoisomeric starting materials were tagged with different fluorous PMB groups and mixed together. The resulting mixture was taken through a series of steps to make the fluorous-tagged products, which were separated by fluorous HPLC followed byhydrogenolysis to provide pure products. The NMR spectra of the eight isomers of hormone alpha 1provided only limited information about their absolute configuration.The synthetic isomers of hormone alpha 1 were subsequently converted to the correspondingbis-R and S Mosher ester derivatives. By comparison of the 1H NMR spectra of the sixteen bis-Mosher ester derivatives with the bis-Mosher ester derivatives of the natural product, weconfirmed the partial configuration of hormone alpha 1 as (3R,7R,11R).
AV  - public
KW  -  phytophthora; fluorous mixture synthesis; Mosher ester
ER  -