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

Green Algae01:21

Green Algae

Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
Red Algae01:23

Red Algae

Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in...
Tonicity in Plants00:53

Tonicity in Plants

Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity delimits the magnitude and direction of osmosis and results in three possible scenarios that alter the volume of a cell: hypertonicity, hypotonicity, and isotonicity. Due to differences in structure and physiology, tonicity of plant cells is different from that of animal cells in some scenarios.Plants and Hypotonic EnvironmentsUnlike animal cells,...
Opioid Analgesics: Morphine and Other Natural Cogeners01:20

Opioid Analgesics: Morphine and Other Natural Cogeners

Opioids are a class of drugs that mimic endogenous opioid peptides and act on opioid receptors, and help in pain relief. These compounds are classified as natural, synthetic, or semi-synthetic. Natural opioids, like morphine, codeine, and thebaine, are derived from the opium poppy plant (Papaver somniferum or Papaver album) and are termed opiates. Synthetic opioids are artificial, while semi-synthetic opioids combine natural and synthetic compounds. Morphine, a prototypical opioid, possesses a...
Seedless Vascular Plants03:24

Seedless Vascular Plants

Seedless Vascular Plants Were the First Tall Plants on Earth
Antifungal Agents01:15

Antifungal Agents

Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to cholesterol contributes to...

You might also read

Related Articles

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

Sort by
Same author

Phytochemical and Pharmacological Studies of Campylospermum Species (Ochnaceae): An Updated Review.

Mini reviews in medicinal chemistry·2026
Same author

Guineenoside B a triterpenoid saponin from Piper guineense (Piperaceae) triggers apoptosis and PI3K/Akt/mTOR inactivation and inhibits metastasis.

BMC complementary medicine and therapies·2026
Same author

Isolation of two polyphenolic compounds from <i>hydnora abyssinica</i> A. Br. Rhizomes by centrifugal partition chromatography and sephadex LH-20.

Natural product research·2026
Same author

New Prenylated Isoflavonoids From Erythrina addisoniae With Anti-Neuroinflammatory Activity via Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells Pathway Suppression.

Chemistry & biodiversity·2026
Same author

Antioxidant potential of a new macrocyclic bisbibenzyl and other compounds from <i>Combretum molle</i>: <i>in vitro</i> and docking analyses.

Drug target insights·2025
Same author

A new limonoid, digsecokigelianolide, among the secondary metabolites from <i>kigelia africana</i> (lam.) benth. and evaluation of their antibacterial and antioxidant activity.

Natural product research·2025

Related Experiment Video

Updated: Jul 20, 2026

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
09:50

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade

Published on: August 14, 2019

Two biflavonoids from Ouratea nigroviolacea.

Josephine Ngo Mbing1, Cécile Enguehard-Gueiffier, Alex de Théodore Atchadé

  • 1Department of Organic Chemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.

Phytochemistry
|September 5, 2006
PubMed
Summary

This study identified two novel biflavonoids, ouratine A and B, from Ouratea nigroviolacea leaves. These compounds, along with known ones, were characterized using spectral and chemical methods.

More Related Videos

Flavonoid Content During the Growth and Floral Development of Calendula officinalis L.
04:54

Flavonoid Content During the Growth and Floral Development of Calendula officinalis L.

Published on: June 27, 2025

Related Experiment Videos

Last Updated: Jul 20, 2026

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
09:50

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade

Published on: August 14, 2019

Flavonoid Content During the Growth and Floral Development of Calendula officinalis L.
04:54

Flavonoid Content During the Growth and Floral Development of Calendula officinalis L.

Published on: June 27, 2025

Area of Science:

  • Phytochemistry
  • Natural Products Chemistry
  • Organic Chemistry

Background:

  • Ouratea nigroviolacea is a plant species belonging to the Ochnaceae family.
  • Biflavonoids are a class of natural products with diverse biological activities.
  • Previous phytochemical investigations of Ouratea species have revealed various secondary metabolites.

Purpose of the Study:

  • To isolate and characterize the chemical constituents from the leaves of Ouratea nigroviolacea.
  • To identify novel biflavonoids and other compounds present in the plant.
  • To elucidate the structures of isolated biflavonoids using spectroscopic and chemical techniques.

Main Methods:

  • Extraction of plant material (leaves of Ouratea nigroviolacea).
  • Chromatographic separation techniques (e.g., column chromatography) for isolation of compounds.
  • Spectroscopic analysis including NMR (Nuclear Magnetic Resonance) and Mass Spectrometry for structural elucidation.
  • Chemical transformation studies to confirm structural assignments.

Main Results:

  • Two biflavonoids, designated ouratine A and ouratine B, were isolated from the leaves.
  • Agathisflavone and stigmasterol were also identified in the extract.
  • Ouratine A was characterized as 4'-O-methylated apigeninyl-(I-6, II-8)-4'-O-methylatedapigenin.
  • Ouratine B was characterized as 4'-O-methylated apigeninyl-(I-6, II-8) apigenin.

Conclusions:

  • The leaves of Ouratea nigroviolacea are a source of unique biflavonoids, ouratine A and B.
  • The structural elucidation confirmed the presence of specific methylation patterns in the isolated biflavonoids.
  • This study contributes to the phytochemical knowledge of the Ouratea genus and the Ochnaceae family.