title: Structural Elucidation of cis/trans Dicaffeoylquinic Acid Photoisomerization Using Ion Mobility Spectrometry-Mass Spectrometry.
abstract: Due to the recently uncovered health benefits and anti-HIV activities of dicaffeoylquinic acids (diCQAs), understanding their structures and functions is of great interest for drug discovery efforts. DiCQAs are analytically challenging to identify and quantify since they commonly exist as a diverse mixture of positional and geometric (cis/trans) isomers. In this work, we utilized ion mobility spectrometry coupled with mass spectrometry to separate the various isomers before and after UV irradiation. The experimental collision cross sections were then compared with theoretical structures to differentiate and identify the diCQA isomers. Our analyses found that naturally the diCQAs existed predominantly as trans/trans isomers, but after 3 h of UV irradiation, cis/cis, cis/trans, trans/cis, and trans/trans isomers were all present in the mixture. This is the first report of successful differentiation of cis/trans diCQA isomers individually, which shows the great promise of IMS coupled with theoretical calculations for determining the structure and activity relationships of different isomers in drug discovery studies.
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Xueyun
authors.identifier: http://orcid.org/0000-0001-9782-4521
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Renslow
authors.affiliation: Department of Biochemistry, University of Johannesburg , P.O. Box 524, Auckland Park 2006, South Africa.
authors.forename: Mpho M
authors.initials: MM
authors.lastname: Makola
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Ian K
authors.initials: IK
authors.lastname: Webb
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Liulin
authors.initials: L
authors.lastname: Deng
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Thomas
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Niranjan
authors.initials: N
authors.lastname: Govind
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Yehia M
authors.identifier: http://orcid.org/0000-0001-6085-193X
authors.initials: YM
authors.lastname: Ibrahim
authors.forename: Mwadham M
authors.initials: MM
authors.lastname: Kabanda
authors.affiliation: Department of Biochemistry, University of Johannesburg , P.O. Box 524, Auckland Park 2006, South Africa.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Dubery
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Heino M
authors.identifier: http://orcid.org/0000-0003-0941-2506
authors.initials: HM
authors.lastname: Heyman
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Richard D
authors.identifier: http://orcid.org/0000-0002-2381-2349
authors.initials: RD
authors.lastname: Smith
authors.affiliation: Department of Biochemistry, University of Johannesburg , P.O. Box 524, Auckland Park 2006, South Africa.
authors.forename: Ntakadzeni E
authors.initials: NE
authors.lastname: Madala
authors.affiliation: Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Erin S
authors.identifier: http://orcid.org/0000-0001-5246-2213
authors.initials: ES
authors.lastname: Baker