Page 128 - Pharmd general phytochemistry I-Final2024_LEUCTERS

BITTER PRINCIPLES AND OTHER MISCELLANEOUS NATURAL PRODUCTS

 Bitter Principles are a group of natural products which are non-homogenous from
the chemical point of view, they have in common an intensely bitter taste and are
neither alkaloids nor glycosides.

 They belong to different chemical groupings such as furanochromones,
furanocoumarins, sesquiterpene lactones, diterpenes, triterpenes, lignans, etc.

 Bitter principles are mainly of vegetative origin, rarely of animal origin.
 They essentially comprise of C, H, and O, but free from or rarely have N.
 They are abundant in certain plant families especially Compositae, Labiatae and

Umbelliferae.
 They were traditionally used in liquid medicaments to stimulate appetite as bitter

stomachic. It has been proposed that bitter principles stimulate the taste buds, thus
producing reflex secretion of gastric juices.
 Many of these bitters and drugs containing them are still included in tonic formulations
and are usually administered before meals. However, they are now mainly used for
other pharmacological activities.

Terpenoids

Definition: These are natural products that are built up of isoprene units. So, all terpe

noids structures can be divided into isoprene units, and they are also called isoprenoids;

they mainly occur in higher plants. The isoprene units arise biogenetically from acetate

via mevalonic acid, it is a branched chain (five carbon unit) containing two double

bonds. During the formation of terpenoids the isoprene units are usually linked in a head

CH3 to tail manner.

CH2=C-CH=CH2 (C5H8)

Head Tail

Isoprene unit

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