Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Are lignins optically active?

J Ralph1, J Peng, F Lu

  • 1U.S. Dairy Forage Research Center, Agricultural Research Service, U. S. Department of Agriculture, Madison, Wisconsin 53706, USA. jralph@facstaff.wisc.edu

Journal of Agricultural and Food Chemistry
|December 20, 1999
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Editorial Expression of Concern: Identification of mutations that disrupt phosphorylation-dependent nuclear export of cyclin D1.

Oncogene·2026
Same author

Experimental Observation of Anomalous Stopping of Mega-ampere Electron Current in Porous Materials.

Physical review letters·2026
Same author

Enhanced S-Factor for the ^{14}N(p,γ)^{15}O Reaction and Its Impact on the Solar Composition Problem.

Physical review letters·2025
Same author

[Trends in adenoidectomy in children in Beijing tertiary hospitals from 2013 to 2022].

Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine]·2025
Same author

Association of High-Sensitivity Cardiac Troponin I, Platelet Counts, and Total Bilirubin/Albumin Ratio with the Severity of Neonatal Hyperbilirubinemia.

Physiological research·2025
Same author

Factors associated with core competencies of infection prevention and control practitioners in 511 hospitals: a large cross-sectional survey in Guizhou, south-west China.

The Journal of hospital infection·2025
Same journal

Discovery of Novel Pyrazole-Benzothiazine Hybrids as Potential HPPD Inhibitors.

Journal of agricultural and food chemistry·2026
Same journal

Structural Regulation of Lignin Using an Al<sup>3+</sup>/Zn<sup>2+</sup> Bimetallic Lewis Acid System to Enhance Enzymatic Saccharification.

Journal of agricultural and food chemistry·2026
Same journal

Comparative NMR-Based Metabolomic and Functional Assessment of Fruit and Vegetable Extracts under Regenerative Agricultural Practices.

Journal of agricultural and food chemistry·2026
Same journal

Fenoxaprop-<i>P</i>-ethyl Disrupts Lipid Homeostasis in Rice Seedlings: A Multiomics Study Linking the Inhibition of Acetyl-Coenzyme A Carboxylase with a Coordinated Repression of Fatty Acid Elongation Processes.

Journal of agricultural and food chemistry·2026
Same journal

Exploiting Biomacromolecular Oligomerization for Next-Generation Pesticide Discovery: Challenges and Perspectives.

Journal of agricultural and food chemistry·2026
Same journal

Design, Synthesis, and Insecticidal Potential of 1,2,4-Oxadiazole-Fused Isoxazoline Derivatives as GABA Receptor Antagonists.

Journal of agricultural and food chemistry·2026
See all related articles

Lignins are generally assumed to be optically active, but this study found they are not. Using advanced techniques, researchers confirmed that lignin samples from various sources exhibit no optical activity within detection limits.

Area of Science:

  • Biochemistry
  • Polymer Science
  • Organic Chemistry

Background:

  • The biosynthesis of lignin, a complex plant polymer, is traditionally attributed to non-enzymatic radical coupling reactions.
  • This proposed mechanism implies that lignins should possess optical activity due to their chiral centers.
  • Recent challenges to this derivation necessitate a re-evaluation of lignin's optical properties.

Purpose of the Study:

  • To definitively determine whether lignins are optically active or inactive.
  • To investigate the stereochemical properties of lignin biosynthesis.
  • To provide empirical evidence regarding the optical nature of lignins.

Main Methods:

  • Derivatization followed by reductive cleavage (DFRC) was used to isolate specific lignin dimers (beta-5 and beta-beta units) from pine lignins.

Related Experiment Videos

  • Circular dichroism (CD) spectroscopy was employed to detect optical activity in isolated dimers and whole lignin samples.
  • Chiral high-performance liquid chromatography (HPLC) was utilized for enantiomeric separation and analysis of DFRC-derived dimers.
  • CD measurements of lignin isolates from diverse plant sources (pine, kenaf, maize) and a CAD-deficient pine mutant were performed above 250 nm to exclude carbohydrate interference.

    • Main Results:

    • DFRC-derived dimers from pine lignins, specifically beta-5 and beta-beta units retaining chiral centers, were found to be optically inactive.
    • Circular dichroism (CD) analysis of these dimers, even after enantiomeric separation, showed no detectable optical activity.
    • No optical activity was detected in lignin isolates from pine, kenaf, maize, or a CAD-deficient pine mutant using CD spectroscopy.
    • The sensitivity of the CD method was confirmed by its ability to detect optical activity in beta-5 derived dimers following enantiomeric separation.

    Conclusions:

    • Representative lignins from various sources are not optically active within the detection limits of the applied methods.
    • The findings challenge the assumption of optical activity in lignins derived from non-enzymatic radical coupling.
    • This study provides critical empirical data for understanding lignin biosynthesis and structure.