alexa Fluorescence lifetimes of tryptophan: structural origin and relation with So --> 1Lb and So --> 1La transitions.
Pharmaceutical Sciences

Pharmaceutical Sciences

Pharmaceutica Analytica Acta

Author(s): Albani JR

Abstract Share this page

Abstract We measured fluorescence lifetimes of L-Tryptophan dissolved in de-ionized water and in ethanol in the absence and the presence of high progesterone concentrations. The hormone absorbs between 220 and 280 with a peak around 250 nm, while its absorption is equal to zero beyond 280 nm. Tryptophan excitation spectrum recorded in presence of progesterone shows that the S(o) --> 1L(a) transition is completely abolished while the S(o) --> 1L(b) transition is not affected. Emission of L-tryptophan in water occurs with two fluorescence lifetimes, 0.40 and 2.8 ns. In ethanol, three fluorescence lifetimes equal to around 0.2, 1.8 and 4.8 ns were observed. Addition of progesterone to the medium does not affect any of the fluorescence lifetimes indicating clearly that both transitions could induce tryptophan excitation and that recorded fluorescence lifetimes could be assigned to sub-structures generated in the excited state. This article was published in J Fluoresc and referenced in Pharmaceutica Analytica Acta

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version