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Iota-Carrageenan Hydrolysis By Pseudoalteromonas Carrageenovora Ifo12985, Bernadette M. Henares, Erwin P. Enriquez, Fabian M. Dayrit, Nina Rosario L. Rojas
Iota-Carrageenan Hydrolysis By Pseudoalteromonas Carrageenovora Ifo12985, Bernadette M. Henares, Erwin P. Enriquez, Fabian M. Dayrit, Nina Rosario L. Rojas
Chemistry Faculty Publications
We report iota-carrageenan hydrolysis by Pseudoalteromonas carrageenovora IFO 12985. Kappa-carrageenase and lambda-carrageenase were previously isolated from this organism, but iota-carrageenase activity had not been reported in the literature. P. carrageenovora was grown in iota-carrageenan-based liquid medium. Using the zone of depression assay, transfer of aliquots of the culture to solid medium with 2% iota- and kappa-carrageenan showed extensive hydrolysis of iota-carrageenan. Analysis of the hydrolysates by C-13 Nuclear Magnetic Resonance spectroscopy confirmed degradation of the iota-carrageenan. Hydrolytic activity of P. carrageenovora grown in iota-carrageenan was compared with that of the same organism grown in kappa-carrageenan. Cell-free supernatants from each yielded …
Acetic Acid Aldol Reactions In The Presence Of Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Miles W. Johnson, Daniel H. Lawrence, Alan S. Fleisher, Kathryn J. Tracy
Acetic Acid Aldol Reactions In The Presence Of Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Miles W. Johnson, Daniel H. Lawrence, Alan S. Fleisher, Kathryn J. Tracy
Chemistry Faculty Publications
In the presence of TMSOTf and a trialkylamine base, acetic acid undergoes aldol addition to non-enolizable aldehydes under exceptionally mild conditions. Acidic workup yields the β-hydroxy carboxylic acid. The reaction appears to proceed via a three-step, one-pot process, including in situ trimethylsilyl ester formation, bis-silyl ketene acetal formation, and TMSOTf-catalyzed Mukaiyama aldol addition. Independently synthesized TMSOAc also undergoes aldol additions under similar conditions.