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 Concept Videos

Oxidation of Phenols to Quinones01:17

Oxidation of Phenols to Quinones

4.9K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
4.9K
Peroxisomes01:24

Peroxisomes

21.6K
Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
21.6K
Properties of Organometallic Compounds01:23

Properties of Organometallic Compounds

1.8K
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
1.8K
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

7.7K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
7.7K
Metal-Ligand Bonds02:51

Metal-Ligand Bonds

24.6K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
24.6K
ortho–para-Directing Deactivators: Halogens01:24

ortho–para-Directing Deactivators: Halogens

7.0K
Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...
7.0K

You might also read

Related Articles

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

Sort by
Same author

A phase II clinical trial of albumin-bound paclitaxel, cisplatin, gemcitabine (NABPLAGEM), and paricalcitol as neoadjuvant therapy in pancreatic cancer.

The oncologist·2026
Same author

Vedolizumab Dose Escalation Resolves Immune Checkpoint Inhibitor-Induced Colitis in Two Patients.

Case reports in oncological medicine·2025
Same author

Investigating biomarkers of exposure to jet aircraft oil fumes using mass spectrometry.

medRxiv : the preprint server for health sciences·2025
Same author

Underway measurement of cyanobacterial microcystins using a surface plasmon resonance sensor on an autonomous underwater vehicle.

Limnology and oceanography, methods·2025
Same author

Impact of Antioxidant and Anti-Inflammatory Functions of HDL in Diseases-2nd Edition.

Antioxidants (Basel, Switzerland)·2025
Same author

Immersive Virtual Reality for Enabling Patient Experience and Enrollment in Oncology Clinical Trials: A Feasibility Study.

Cancers·2025
Same journal

Correction to: Recent Structural Insights into the Molecular Architecture of Synapses.

Advances in neurobiology·2026
Same journal

Roles of Glia in Synapse Nano-organization.

Advances in neurobiology·2026
Same journal

Visualizing Postsynaptic Density in Excitatory Synapses with Electron Tomography.

Advances in neurobiology·2026
Same journal

Optical Approaches to Dissect the Structure and Dynamics of the Synapse at Nanoscale Resolution.

Advances in neurobiology·2026
Same journal

Functional Nano-segregation of Distinct Forms of Neurotransmission.

Advances in neurobiology·2026
Same journal

Scales of Postsynaptic Nanostructure: Molecules, Nanoclusters, and Nanodomains.

Advances in neurobiology·2026
See all related articles

Related Experiment Video

Updated: Feb 23, 2026

Fast and Specific Assessment of the Halogenating Peroxidase Activity in Leukocyte-enriched Blood Samples
05:17

Fast and Specific Assessment of the Halogenating Peroxidase Activity in Leukocyte-enriched Blood Samples

Published on: July 28, 2016

10.7K

Metals and Paraoxonases.

Lucio G Costa1,2, Toby B Cole3,4, Jacqueline M Garrick3

  • 1Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE, Suite 100, Seattle, WA, 98105, USA. lgcosta@uw.edu.

Advances in Neurobiology
|September 11, 2017
PubMed
Summary
This summary is machine-generated.

Paraoxonases (PONs) are crucial enzymes with antioxidant and protective roles. Metal exposure can negatively impact PON expression, affecting susceptibility to toxicity and neurotoxicity.

Keywords:
CadmiumLeadManganeseMercuryMetalsOxidative stressParaoxonases

More Related Videos

Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
05:47

Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts

Published on: August 7, 2018

8.2K
High Resolution Physical Characterization of Single Metallic Nanoparticles
09:56

High Resolution Physical Characterization of Single Metallic Nanoparticles

Published on: June 28, 2019

6.2K

Related Experiment Videos

Last Updated: Feb 23, 2026

Fast and Specific Assessment of the Halogenating Peroxidase Activity in Leukocyte-enriched Blood Samples
05:17

Fast and Specific Assessment of the Halogenating Peroxidase Activity in Leukocyte-enriched Blood Samples

Published on: July 28, 2016

10.7K
Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
05:47

Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts

Published on: August 7, 2018

8.2K
High Resolution Physical Characterization of Single Metallic Nanoparticles
09:56

High Resolution Physical Characterization of Single Metallic Nanoparticles

Published on: June 28, 2019

6.2K

Area of Science:

  • Biochemistry and Molecular Biology
  • Enzymology
  • Toxicology

Background:

  • Paraoxonases (PONs) comprise a three-gene family (PON1, PON2, PON3) with diverse enzymatic activities, including esterase, lactonase, and antioxidant functions.
  • PON1 and PON3 are secreted and associated with HDL, while PON2 is intracellular, with expression in various tissues including the brain.
  • PONs are implicated in cardiovascular health, oxidative stress-related diseases, infection susceptibility, and neuroprotection.

Purpose of the Study:

  • To explore the multifaceted roles of paraoxonases (PONs) in health and disease.
  • To investigate the impact of various factors, particularly metals, on PON expression and function.
  • To understand how PONs influence susceptibility to metal toxicity and neurotoxicity.

Main Methods:

  • Literature review of in vitro, animal, and human studies.
  • Analysis of PON gene family members (PON1, PON2, PON3) and their respective functions.
  • Examination of factors modulating PON expression, with a focus on metal interactions.

Main Results:

  • PONs exhibit esterase, lactonase, and significant antioxidant activities.
  • Metals have been shown to negatively modulate PON expression, especially PON1.
  • Altered PON expression levels can influence an individual's susceptibility to metal toxicity and neurotoxicity.

Conclusions:

  • Paraoxonases are vital enzymes with broad physiological relevance.
  • Metal exposure poses a risk by negatively affecting PON expression and function.
  • Understanding PON modulation is critical for addressing metal-induced toxicity and neurotoxicity.