Related Experiment Video

Updated: Jun 19, 2026

High-resolution Tandem Mass Spectrometry for Studying Chemical Constituents of Gynura bicolor DC
07:16

High-resolution Tandem Mass Spectrometry for Studying Chemical Constituents of Gynura bicolor DC

Published on: February 2, 2024

[New homoisoflavanones from Polygonatum odoratum (Mill.) Druce]

Li-Hong Li1, Feng-Zhi Ren, Shu-Hong Chen

  • 1Department of Natural Products, Drug Discovery of North China Pharmaceutical Company, Shijiazhuang 050015, China. llhong21@163.com

Yao Xue Xue Bao = Acta Pharmaceutica Sinica
|October 8, 2009
PubMed

More Related Videos

Screening and Isolation of C-Glycoside-Cleaving Intestinal Bacteria06:38

Screening and Isolation of C-Glycoside-Cleaving Intestinal Bacteria

Published on: February 28, 2025

An Efficient and Rapid HPLC-QQQ-MS Method for the Quantitation of Tropane Alkaloids in Medicinal Plants09:10

An Efficient and Rapid HPLC-QQQ-MS Method for the Quantitation of Tropane Alkaloids in Medicinal Plants

Published on: June 12, 2026

Related Concept Videos

Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence01:27

Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence

Changes in polymorphic forms can significantly influence the bioavailability of poorly soluble drugs. Although the FDA defines pharmaceutical equivalence based on having the same active ingredient, dosage form, and route of administration, it does not automatically disqualify products with different polymorphic forms. This means two products with different polymorphs can still be deemed pharmaceutically equivalent. However, polymorphic differences can affect properties like wettability,...
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...
Preparation of Diols and Pinacol Rearrangement01:57

Preparation of Diols and Pinacol Rearrangement

Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
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...
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors01:19

Oral Hypoglycemic Agents: α-Glucosidase Inhibitors

α-glucosidase inhibitors, including acarbose (Precose), miglitol (Glyset), and voglibose (Voglib) (primarily available in Asia), are drugs that control blood sugar levels by delaying the digestion of starch and disaccharides. They achieve this by inhibiting α-glucosidase enzymes in the intestine, which slow the absorption of carbohydrates in the intestine, which in turn leads to a prolonged release of the glucoregulatory hormone GLP-1 from intestinal L-cells.
Acarbose and miglitol are typically...
Stereoisomerism of Cyclic Compounds02:33

Stereoisomerism of Cyclic Compounds

In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...