High Resolution Solid State ¹³C NMR Spectroscopy of Sporopollenins from Different Plant Taxa

Abstract

ABSTRACrThe extremely chemically resistant component of the cell wall of spores, polens, and some microorganisms, sporopolenin, is generaly accepted to be derived from carotenoids or carotenoid esters. However, we report here that '3C NMR analyses of sporopoUenin from several sources shows that this widely held view is incorrect, with one possible exception. Sporopollenin is not a unique substance but rather a series of related biopolymers derived from largely saturated precursors such as fatty adds. The biopolymers contain widely varying amounts of oxygen in the form of ether, hydroxyl, carboxylic acid, ester, and ketone groups.The outer cell wall, or exine, of many spores, pollens, and certain microorganisms is made of sporopollenin. The

Novel Phenanthrene Sorption Mechanism by Two Pollens and Their Fractions

“…41 An increase in Phen sorption affinity and nonlinearity by lignin-coated biopolymers as compared to chitin and cellulose was contributed to the newly created high-energy sites in condensed domains and coated lignin, very likely due to π−π interactions. 19,41 Sporopollenins are composed of alkyl carbon and poly-(methylene) carbon 40,49 and tend to exhibit a high sorption affinity for Phen, as demonstrated in this study. The results of this study suggest that poly(methylene) carbon, alkyl, and aromatic domains, as well as the composition and accessibility of NOM, require more attention when the uptake, sequestration, and bioavailability of organic contaminants are considered in the examination of sorption processes in the natural environment.…”

“…The structure of the NHC fractions in pollen samples is similar to that reported for sporopollenin, which principally contains aliphatic, aromatic, ether, and carbonyl and carboxylic groups in varying degrees. 29,30,32,40 NMR spectroscopy therefore indicates that the investigated NHC fractions are the same as sporopollenin. All of these observed structures will significantly affect their affinities to HOC, which will be discussed later.…”

“…Previous studies have also indicated that sporopollenin is not a uniform macromolecule but rather a series of closely related biopolymers with different chemical groups occurring in varying amounts. 29,40 Sorption Isotherms. All of the Freundlich sorption isotherms for Phen are well fitted by the Freundlich eq (Table 3 and Figure S3).…”

LAP3, a novel plant protein required for pollen development, is essential for proper exine formation

“…lap3-2 leads to a wide variety of metabolic consequences in developing anthers. Given the model of sporopollenin composed of fatty acid and phenolic compounds (Guilford et al 1988;Kawase and Takahashi 1995;Ahlers et al 1999Ahlers et al , 2000Ahlers et al , 2003Dominguez et al 1999;MeuterGerhards et al 1999;Bubert et al 2002), it is of interest to note that some changes were detected in the levels of lipids (such as a-linolenic acid, 1-18:3-lysophophatidylethanolamine, 1-16:0-lysophophatidylethanolamine, a-eleosteric acid, and 10E,12Z-octadecadienoic acid, linoleic acid, nonacosane and palmitic acid) and of at least one phenylpropanoid (naringenin chalcone).…”

“…In addition, a possibility exists that sporopollenin is not a single substance, but instead varies chemically between species and even between different stages of development (Hemsley et al 1993;Meutergerhards et al 1995). Despite these difficulties, tracer experiments, NMR and spectroscopic/spectrometric studies have yielded a model of sporopollenin composed of polyhydroxylated unbranched aliphatics and phenolics covalently coupled with ether and ester linkages (Guilford et al 1988;Kawase and Takahashi 1995;Ahlers et al 1999Ahlers et al , 2000Ahlers et al , 2003Dominguez et al 1999;Meuter-Gerhards et al 1999;Bubert et al 2002).…”