The physical and chemical properties and uses of quinolones

11.
1.
1 Physical and chemical properties and uses

Quinolones (quinolones, QNs), also known as pyridonic acids or pyridonic acids, are compounds with 1,4-dihydro-4-oxopyridine-3-carboxylic acid as the basic ring structure.
They are derived from nalidixic acid or The basic structure of a synthetic antibacterial drug derived from pyridoxine is shown in Figure 11-1
.

In 1962, Lesher et al.
discovered the first QNs-nalidixic acid, and through structural modification and modification of it, it enhanced its biological and pharmacological activities
.

Figure 11-1 Basic structure of QNs

The introduction of fluorine atoms at the C _⁶ position has become a significant feature of the FQs structure
.

In 1997, Aandriole proposed to use the Aandriole-Schellhore classification method compiled by Schellhore to divide QNs into four generations.
The international academic community also divided the development of QNs into four stages according to this method: the first generation of QNs, the main representative is nalidixic acid, Only effective against Escherichia coli, Shigella, Pneumoniae, Proteus and Salmonella, etc.
: It has weak or ineffective effect on Gram-positive bacteria and Pseudomonas aeruginosa
.

11.
1.
1.
1 Physical and chemical properties

QNs are all white or light yellow crystalline powders
.

Table 11-1 Physical and chemical properties of commonly used QNs