Demystifying and Unravelling the Factual Molecular Structure of the Biopolymer Sporopollenin

Sporopollenin is a natural, highly cross-linked biopolymer composed of carbon, hydrogen, and oxygen, which forms the outer wall of pollen grains. Sporopollenin is resilient to chemical degradation. Because of this stability, its exact chemical structure and the biochemical pathways involved in its biosynthesis remains a mystery and unresolved. We have identified and characterized the molecular structure of the clean, intact sporopollenin using soft ionization mass spectrometric and nuclear magnetic resonance techniques. These analyses showed that sporopollenin contained a poly(hydroxyacid) dendrimer-like network, which accounted for the sporopollenin empirical formula. In addition, the identified hydroxy acid monomers contained a beta diketone moiety, which most probably accounts for the known antioxidant activity of sporopollenin. Moreover, our elucidation studies allowed us to identify a unique circular polyhydroxylated tetraketide polymer. This polymer acted as the rigid backbone on which the poly(hydroxyacid) network can be built, forming the scaffold of the spherical sporopollenin exine.

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Demystifying and Unravelling the Factual Molecular Structure of the Biopolymer Sporopollenin

10.26434/chemrxiv.10059860.v1 ◽

2019 ◽

Author(s):

Abanoub Mikhael ◽

Kristina Jurcic ◽

Celine Schneider ◽

David carr ◽

Gregory L. Fisher ◽

...

Keyword(s):

Molecular Structure ◽

Biomedical Applications ◽

Chemical Structure ◽

Pollen Grains ◽

Outer Wall ◽

Mass Spectrometric ◽

Chemical Degradation ◽

Wastewater Purification ◽

Biochemical Pathways ◽

Micro Reactors

Sporopollenin is a natural highly cross-linked biopolymer composed of carbon, hydrogen, and oxygen which forms the outer wall of pollen grains. Sporopollenin is resilient to chemical degradation. Because of this stability, its exact chemical structure and the biochemical pathways involved in its biosynthesis remains a mystery and unresolved. It is obvious that a well-conceived coherent study of the sporopollenin structure details will help immensely scientists in better understanding the chemistry of their current applications of sporopollenin exines such as drug delivery, peptide synthesis, micro-reactors, and wastewater purification. As well, it may also lead to the discovery of newer biomedical applications in the next coming years. We have identified and characterized the molecular structure of the clean, intact sporopollenin using mass spectrometric and nuclear magnetic resonance techniques. These analyses showed that sporopollenin is composed of a circular polyhydroxylated tetraketide polymer rigid backbone and a poly(hydroxyacid) branched network. The poly(hydroxyacid) network chains are attached by covalantly ether bonds to the polyhydroxylated tetraketides rigid backbone, forming the scaffold of the spherical sporopollenin.

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The molecular structure of plant sporopollenin

10.1101/415612 ◽

2018 ◽

Author(s):

Fu-Shuang Li ◽

Pyae Phyo ◽

Joseph Jacobowitz ◽

Mei Hong ◽

Jing-Ke Weng

Keyword(s):

Molecular Structure ◽

Minor Component ◽

Pollen Grains ◽

Outer Wall ◽

Land Plant ◽

Spores And Pollen ◽

Biomimetic Polymers ◽

Wide Range ◽

Nmr Techniques ◽

A Minor

Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains. Sporopollenin protects the vulnerable plant gametes against a wide range of environmental assaults, and is considered as a prerequisite for the migration of early plants onto land. Despite its importance, the chemical structure of plant sporopollenin has remained elusive. Using a newly developed thioacidolysis degradative method together with state-of-the-art solid-state NMR techniques, we determined the detailed molecular structure of pine sporopollenin. We show that pine sporopollenin is primarily composed of aliphatic-polyketide-derived polyvinyl alcohol units and 7-O-p-coumaroylated C16 aliphatic units, crosslinked through a distinctive m-dioxane moiety featuring an acetal. Naringenin was also identified as a minor component of pine sporopollenin. This discovery answers the long-standing question about the chemical makeup of plant sporopollenin, laying the foundation for future investigations of sporopollenin biosynthesis and for design of new biomimetic polymers with desirable inert properties.

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New Challenges in Development of Soft-Ionization Mass Spectrometric Techniques for Fullerene Derivatives

ECS Meeting Abstracts ◽

10.1149/ma2007-01/28/1092 ◽

2007 ◽

Keyword(s):

Mass Spectrometric ◽

Ionization Mass ◽

Fullerene Derivatives ◽

Soft Ionization ◽

New Challenges ◽

Mass Spectrometric Techniques

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A New Arylnaphthalide Lignan From Oxalis corniculata

Natural Product Communications ◽

10.1177/1934578x19875885 ◽

2019 ◽

Vol 14 (9) ◽

pp. 1934578X1987588

Author(s):

Bao Zhang ◽

Li Jiang ◽

Xue Ma ◽

Ai-Min Wang ◽

Ting Liu ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Chemical Structure ◽

Mass Spectrometric ◽

Mass Spectrometric Analysis ◽

Spectrometric Analysis ◽

Etoh Extract ◽

Nuclear Magnetic

A new arylnaphthalide lignan, corniculin (1), was isolated from 75% EtOH extract of Oxalis corniculata. Its chemical structure was determined by mass spectrometric analysis as well as 1D and 2D nuclear magnetic resonance (NMR).

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Elucidation of the Mechanism of Action for Metal Based Anticancer Drugs by Mass Spectrometry-Based Quantitative Proteomics

Molecules ◽

10.3390/molecules24030581 ◽

2019 ◽

Vol 24 (3) ◽

pp. 581 ◽

Cited By ~ 7

Author(s):

Shuailong Jia ◽

Runjing Wang ◽

Kui Wu ◽

Hongliang Jiang ◽

Zhifeng Du

Keyword(s):

Mass Spectrometry ◽

Anticancer Drugs ◽

Mechanism Of Action ◽

Quantitative Proteomics ◽

High Sensitivity ◽

Mass Spectrometric ◽

Protein Adducts ◽

Ionization Mass ◽

Soft Ionization ◽

Binding Partners

The discovery of the anticancer activity of cisplatin and its clinical application has opened a new field for studying metal-coordinated anticancer drugs. Metal-based anticancer drugs, such as cisplatin, can be transported to cells after entering into the human body and form metal–DNA or metal–protein adducts. Then, responding proteins will recognize adducts and form stable complexes. The proteins that were binding with metal-based anticancer drugs were relevant to their mechanism of action. Herein, investigation of the recognition between metal-based anticancer drugs and its binding partners will further our understanding about the pharmacology of cytotoxic anticancer drugs and help optimize the structure of anticancer drugs. The “soft” ionization mass spectrometric methods have many advantages such as high sensitivity and low sample consumption, which are suitable for the analyses of complex biological samples. Thus, MS has become a powerful tool for the identification of proteins binding or responding to metal-based anticancer drugs. In this review, we focused on the mass spectrometry-based quantitative strategy for the identification of proteins specifically responding or binding to metal-based anticancer drugs, ultimately elucidating their mechanism of action.

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