Alkaloids Derived from Anthranilic Acid

2.2 Alkaloids Derived from Anthranilic Acid

Anthranilic acid is found to be a key intermediate in the biosynthesis of L-tryptophan. Therefore, it has been established that this biotransformation ultimately is solely responsible to the elaboration of the indole alkaloids. In the course of this conversion, the anthranilic acid residue is specifically decarboxylated, thus the C₆N skeleton is further utilized. In general, there are several such instances wherein the anthranilic acid itself serves as an alkaloid precursor, by employing various means and processes that essentially retain the full skeleton and further exploit the carboxyl function legitimately.

Interestingly, in mammals, L-tryptophan gets degraded back to anthranilic acid. However, this particular route is of least importance in the plant kingdom.

The alkaloids derived from anthranilic acid may be classified into three major categories, namely:

(i)Quinazoline alkaloids,

(ii)Quinoline alkaloids, and

(iii)Acridine alkaloids.

The aforesaid categories of alkaloids shall be discussed in an elaborated fashion hereunder individually.
Source:Pharmacognosy And Pharmacobiotechnology By Ashutosh Kar