title: Isolation and structure determination of a novel spiro-gamma-lactam, spiro-arogenate.
abstract: The eucaryotic microorganism, Neurospora crassa, is able under specified conditions (Zamir, L.O., Jung, E., and Jensen, R.A. (1982) J. Biol. Chem. 258, 6492-6496) to synthesize a cyclohexadienyl derivative of prephenic acid having the novel structure of a spiro-gamma-lactam. This L-gamma-(spiro-4-hydroxy-2,5-cyclohexadienyl)-pyroglutamate is herein given the trivial name, spiro-arogenate, to indicate its close relationship to the amino acid, L-arogenate. Spiro-arogenate is quantitatively converted to phenylalanine at mildly acidic pH and can be converted to arogenate by boiling at basic pH. The structure of spiro-arogenate was established through the application of spectroscopic techniques (ultraviolet, 1H-NMR, 13C-NMR, and mass spectrometry). The 1H-NMR and 13C-NMR spectra of spiro-arogenate isolated as the natural product conformed to the spectrum of spiro-arogenate prepared by chemical synthesis by S. Danishefsky and co-workers (Danishefsky, S., Morris, J., and Clizbe, L.A. (1981) J. Am. Chem. Soc. 103, 1602-1604). Circular dichroism established the S configuration of the asymmetric carbon at C-8 of spiro-arogenate.
mesh_terms: D000600:Amino Acids, Dicarboxylic; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D053138:Cyclohexenes; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009491:Neurospora / Q000032:analysis*; D009492:Neurospora crassa / Q000032:analysis*; D010649:Phenylalanine; D011760:Pyrrolidinones / Q000302:isolation & purification*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives / Q000302:isolation & purification*; D014443:Tyrosine / Q000031:analogs & derivatives
chemical_list: D000600:Amino Acids, Dicarboxylic; D053138:Cyclohexenes; D011760:Pyrrolidinones; D014443:Tyrosine; D010649:Phenylalanine; C015478:pretyrosine; C038112:delta-(spiro-4-hydroxy-2,5-cyclohexadienyl)pyroglutamate; D011761:Pyrrolidonecarboxylic Acid