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

Co-activators and Co-repressors02:04

Co-activators and Co-repressors

8.6K
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
8.6K
tRNA Activation02:26

tRNA Activation

23.0K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
23.0K
Activation Energy01:26

Activation Energy

86.7K
Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the rate of the reaction. However, adding heat to the reaction will increase the rate, since it causes molecules to move faster and increase the likelihood that molecules will collide. The collision and breaking of bonds represents the uphill phase of a reaction and generates the transition state. The transition state is an unstable high-energy state...
86.7K
Eukaryotic Transcription Activators02:42

Eukaryotic Transcription Activators

12.8K
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
12.8K
Secondary Active Transport01:55

Secondary Active Transport

137.9K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
137.9K
Primary Active Transport01:47

Primary Active Transport

198.9K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction...
198.9K

You might also read

Related Articles

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

Sort by
Same author

Phytochemical Profiling and Antioxidant and Enzymatic Evaluation of Extracts from the Antarctic Lichens <i>Polycauliona candelaria</i> and <i>Placopsis antarctica</i>.

Molecules (Basel, Switzerland)·2026
Same author

<i>Larrea ameghinoi</i> Speg. (Zygophyllaceae) "Jarilla Rastrera": UHPLC-ESI-QTOF-MS Analysis, Antioxidant, Antimicrobial Properties, and Inhibition of Enzymes of Interest to Human Health.

Antioxidants (Basel, Switzerland)·2026
Same author

Chemical Composition, Antioxidant, and Anti-Inflammatory Activity of the Antarctic Lichen <i>Leptogium puberulum</i>: A Combination of Metabolomic, In Vitro, and In Silico Approaches.

International journal of molecular sciences·2026
Same author

Phytochemical Profiling of <i>Sticta caulescens</i> De Not.: Green Extraction and Multiscale Chemotaxonomic Analysis.

Plants (Basel, Switzerland)·2026
Same author

Screening for antioxidant and enzyme inhibitory activities of medicinal plants traditionally used as antidiabetics in the Peruvian amazon.

Natural product research·2026
Same author

Nanostructured Lipid Carriers as Physicochemical Modulators of Complex Natural Extracts: Release Behavior and Bile-Induced Remodeling in Biorelevant Media.

Molecules (Basel, Switzerland)·2026

Related Experiment Video

Updated: Feb 5, 2026

Measurement of Larval Activity in the Drosophila Activity Monitor
09:30

Measurement of Larval Activity in the Drosophila Activity Monitor

Published on: April 30, 2015

9.9K

Gastroprotective Activity of Parastrephia quadrangularis (Meyen), Cabrera from the Atacama Desert.

Alejandro Ardiles1, Ruth Barrientos2, Mario J Simirgiotis3,4

  • 1Departamento de Química y Farmacia, Facultad de Ciencias, Universidad Católica del Norte, Angamos 0610, Antofagasta 1240000, Chile. alejandro.ardiles@ucn.cl.

Molecules (Basel, Switzerland)
|September 19, 2018
PubMed
Summary

This study identified new compounds in P. quadrangularis, with some tremetones and clerodanes showing significant gastroprotective activity. P-coumaroyloxytremetone demonstrated superior efficacy compared to lansoprazole in a mouse model.

Keywords:
LC-MS/MSclerodanesendemic plantsgastric ulcergastroprotectivetremetones

More Related Videos

In vitro Reconstitution of the Active T. castaneum Telomerase
09:25

In vitro Reconstitution of the Active T. castaneum Telomerase

Published on: July 14, 2011

12.1K
Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software
06:50

Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software

Published on: October 30, 2018

9.9K

Related Experiment Videos

Last Updated: Feb 5, 2026

Measurement of Larval Activity in the Drosophila Activity Monitor
09:30

Measurement of Larval Activity in the Drosophila Activity Monitor

Published on: April 30, 2015

9.9K
In vitro Reconstitution of the Active T. castaneum Telomerase
09:25

In vitro Reconstitution of the Active T. castaneum Telomerase

Published on: July 14, 2011

12.1K
Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software
06:50

Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software

Published on: October 30, 2018

9.9K

Area of Science:

  • Phytochemistry
  • Pharmacology

Background:

  • The ethanolic extract of P. quadrangularis is traditionally used in ethnobotany.
  • Understanding its chemical constituents and their biological activities is crucial.

Purpose of the Study:

  • To identify metabolites in P. quadrangularis.
  • To evaluate the gastroprotective potential of isolated compounds.

Main Methods:

  • Ultra-high-performance liquid chromatography-quadrupole Orbitrap mass spectrometry (UHPLC-Orbitrap-MS) for metabolite identification.
  • In vivo gastroprotection assay using the HCl/EtOH-induced lesion model in mice.

Main Results:

  • Forty-three metabolites, including methoxylated flavonoids, tremetones, and ent-clerodane diterpenes, were identified.
  • A new tremetone (compound 6) was isolated and characterized.
  • Isolated clerodanes and tremetones exhibited gastroprotective effects.
  • Compound 7 (p-coumaroyloxytremetone) showed the highest gastroprotective activity (76%), surpassing the control drug lansoprazole (72%).

Conclusions:

  • P. quadrangularis is a rich source of bioactive tremetones and terpenoids.
  • P-coumaroyloxytremetone serves as a promising lead compound for developing novel gastroprotective agents.
  • The findings support the ethnobotanical applications of P. quadrangularis.