The Nature of Oxygen in Sporopollenin from the Pollen of Typha angustifolia L.

2000 ◽  
Vol 55 (3-4) ◽  
pp. 129-136 ◽  
Author(s):  
Friedhelm Ahlers ◽  
Henning Bubert ◽  
Stefan Steuernage ◽  
Rolf Wiermann

Abstract Native and peracetylated sporopollenin from the pollen of Typha angustifolia L. was investigated using several spectroscopic methods, inducing Fourier transform infrared spectroscopy (FTIR), solid-state 13C-nuclear magnetic resonance spectroscopy ( 13C-NMR) and Xray photoelectron spectrometry (XPS). Interpretation of the experimental data shows that the greater part of oxygen found in sporopollenin originates from hydroxyl groups and must be derived from aliphatics and not from aromatics. This result indicates that not only aromatics and long unbranched aliphatics but also poly-hydroxyl aliphatic components are involved in the complex structure of the polymer. Furthermore, it is most probable that the monomers of the sporopollenin skeleton are linked by ether- and not by ester-linkage. Two possible approaches are suggested for the characterisation of sporopollenin structure.

1973 ◽  
Vol 46 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Yasuhide Alaki ◽  
Toshio Yoshimoto ◽  
Mamoru Imanari ◽  
Makoto Takeuchi

Abstract Carbon-13 proton nuclear magnetic resonance (NMR) of poly(butadiene) s consisting of various ratios of cis-1,4-, trans-1,4- and 1,2-structures were measured by the pulsed Fourier transform NMR method. The spectra of poly(butadiene)s with two or three kinds of butadiene configurations show several new signals which were not observed for homopolymers comprising merely one kind of butadiene configuration. All of these peaks are ascribed to the carbons linked by different kinds of configurations. From these results, the configurational sequence structure of butadiene units in polymer chains has been revealed.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chuanjiang Li ◽  
Hui Wang ◽  
Manuel Juárez ◽  
Eric Dongliang Ruan

Maillard reaction is a nonenzymatic reaction between reducing sugars and free amino acid moieties, which is known as one of the most important modifications in food science. It is essential to characterize the structure of Amadori rearrangement products (ARPs) formed in the early stage of Maillard reaction. In the present study, the Nα-acetyl-lysine-glucose model had been successfully set up to produce ARP, Nα-acetyl-lysine-glucose. After HPLC purification, ARP had been identified by ESI-MS with intense [M+H]+ ion at 351 m/z and the purity of ARP was confirmed to be over 90% by the relative intensity of [M+H]+ ion. Further structural characterization of the ARP was accomplished by using nuclear magnetic resonance (NMR) spectroscopy, including 1D 1H NMR and 13C NMR, the distortionless enhancement by polarization transfer (DEPT-135) and 2D 1H-1H and 13C-1H correlation spectroscopy (COSY) and 2D nuclear overhauser enhancement spectroscopy (NOESY). The complexity of 1D 1H NMR and 13C NMR was observed due to the presence of isomers in glucose moiety of ARP. However, DEPT-135 and 2D NMR techniques provided more structural information to assign the 1H and 13C resonances of ARP. 2D NOESY had successfully confirmed the glycosylated site between 10-N in Nα-acetyl-lysine and 7′-C in glucose.


1996 ◽  
Vol 79 (2) ◽  
pp. 423-425 ◽  
Author(s):  
George A Moniz ◽  
Gerald B Hammond

Abstract A new method for the separation and identification of ambrein in ambergris using adsorption chromatography and 1H and 13C Fourier transform nuclear magnetic resonance spectroscopy (FT-NMR) is presented. We demonstrated the effectiveness of this method by analyzing an approximately 85-year-old sample of suspected ambergris from the New Bedford Whaling Museum (New Bedford, MA). Results prove that ambrein remains a major constituent of ambergris even after 85 years of storage under ordinary conditions.


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