Eight new C21-steroidal glycosides from the roots of Cynanchum auriculatum

Ya-Yu Wu1, Lan-Wen Gao2, Yu-Jun Tang1

  • 1State Key Laboratory of Bioactive Molecules and Druggability Assessment, Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou 511443, PR China.

Fitoterapia
|April 2, 2025
PubMed

Related Concept Videos

Covalent Bonding and Lewis Structures02:46

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual attraction of atoms for a “shared” pair of electrons. 
47.4K
Lattice Centering and Coordination Number02:33

Lattice Centering and Coordination Number

The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
9.5K
Exceptions to the Octet Rule02:55

Exceptions to the Octet Rule

Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:
27.2K
Electron Configuration of Multielectron Atoms03:26

Electron Configuration of Multielectron Atoms

The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
38.0K
Five-Membered Heterocyclic Aromatic Compounds: Overview01:13

Five-Membered Heterocyclic Aromatic Compounds: Overview

Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom,...
3.6K
Cattell's 16 Personality Factors01:24

Cattell's 16 Personality Factors

Raymond Cattell's trait theory offers a structured framework for understanding personality by distinguishing between two critical traits: surface and source traits. Surface traits are observable patterns of behavior, such as indecisiveness, anxiety, and irrational fears. These traits are less stable, varying across situations and over time. This means that they are less helpful in understanding the deeper aspects of an individual's personality.
In contrast, source traits are the...
322