Detailed characterization of Pinus ponderosa sporopollenin by infrared spectroscopy. (February 2020)

• Record Type: Journal Article
• Authors: Lutzke, Alec; Morey, Kevin J.; Medford, June I.; Kipper, Matt J.
• Is Part Of: Phytochemistry. Volume 170(2020)
• Publication Date: 2020-02
• Subjects: Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2019.112195
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: In plant spores and pollen, sporopollenin occurs as a structural polymer with remarkable resistance to chemical degradation. This recalcitrant polymer is well-suited to analysis by non-destructive infrared spectroscopy. However, existing infrared characterization of sporopollenin has been limited in scope and occasionally contradictory. This study provides a comprehensive structural analysis of sporopollenin in the Pinus ponderosa pollen exine using infrared spectroscopy, including detailed band assignments, descriptions of chemical reactivity, and comparison to multiple reference substances. We observe that the infrared spectral characteristics of sporopollenin prepared by enzymatic digestion of the polysaccharide-based intine are largely consistent with a copolymer of aliphatic lipids and trans -4-hydroxycinnamic acid, without distinct contributions from α-pyrone or carotenoid substructures. Graphical abstract: Image 1 Highlights: Sporopollenin consists primarily of trans- 4-hydroxycinnamic and fatty acids. Terpenoids and α-pyrones are not detected in the structure of sporopollenin. Common methods for sporopollenin isolation result in chemical derivatization. IR spectroscopy reveals sporopollenin chemistry as it exists in planta.