19 - MIXED ORIGIN ALKALOIDS Flashcards
MIEXED ORIGIN ALKALOIDS
A.- Imidazole alkaloids: histidine derivatives • B.- Terpenoid alkaloids: Diterpenoid Steroidal • C.- Purine alkaloids
HISTIDINE-DERIVED ALKALOIDS (CHARACTERISTICS AND CRUDE DRUGS)
The amino acid L-histidine contains an imidazole ring, and a precursor of alkaloids containing this ring system.
Jeborandi, Pilocarpus
Alkaloid; policarpine
HISTIDINE-DERIVED ALKALOIDS (ALKALOIDS)
The crude drug contains 0.5–1.0% of the imidazole alkaloid pilocarpine together with small amounts of pilosine and related structures such as isopilocarpine.
PILOCARPINE
HISTIDINE-DERIVED ALKALOIDS
Pilocarpine salts are valuable in ophthalmic practice and are used in
eyedrops as miotic (cause contraction of the pupil of the eye, being
antagonistic to that of atropine) and for the treatment of glaucoma (serve
to increase the irrigation of the eye and relieve pressure).
Pilocarpine is a cholinergic agent and stimulates the muscarinic
receptors in the eye, causing constriction of the pupil and enhancement
of outflow of aqueous humour.
As antagonistic to atropine, pilocarpine relief dryness of the mouth that
results in patients treated with radiotherapy for mouth and throat
cancers.
HISTIDINE-DERIVED ALKALOIDS (SPANISH PHARMACEUTIC SPECIALITIES)
Salagen® tablets, composition per unit:
Pilocarpine hydrochloride 5 mg
Therapeutic indications: Relief of symptoms of salivary glands hypofunction
in patients with severe xerostomia (dry mouth), post-radiotherapy in head and
neck cancer. Treatment of symptoms of dry mouth and dry eyes in patients with
Sjögren’s syndrome.
Colircusí Pilocarpina® eye drops, composition: 2% solution of pilocarpine
chloride.
Therapeutic indications: glaucoma, induction of myosis.
Salagen® tablets
HISTIDINE-DERIVED ALKALOIDS (SPANISH PHARMACEUTIC SPECIALITIES)
Salagen® tablets, composition per unit:
Pilocarpine hydrochloride 5 mg
Therapeutic indications: Relief of symptoms of salivary glands hypofunction
in patients with severe xerostomia (dry mouth), post-radiotherapy in head and
neck cancer. Treatment of symptoms of dry mouth and dry eyes in patients with
Sjögren’s syndrome.
Colircusí Pilocarpina® eye drops,
HISTIDINE-DERIVED ALKALOIDS (SPANISH PHARMACEUTIC SPECIALITIES)
Colircusí Pilocarpina® eye drops, composition: 2% solution of pilocarpine
chloride.
Therapeutic indications: glaucoma, induction of myosis.
TERPENOID ALKALOIDS
Many alkaloids are synthesized primarily from non-amino acid precursors,
being the nitrogen atom inserted into the structure at a relatively late stage.
These structures are frequently based on terpenoid or steroidal skeletons,
and in most of cases the nitrogen atom is donated from an amino acid source
through a transamination reaction with a suitable aldehyde or ketone.
DITERPENOID ALKALOIDS
Aconite, Wolfsbane, Monkshood Root of Aconitum napellus L. (Ranunculaceae) The crude drug contains toxic alkaloids (0.3–1.5%) that are complex diterpene-derived esters. Aconitine (main compound, about 30%) with no therapeutic use due to its toxicity, is a diester of aconine with acetic and benzoic acids. These alkaloids appear to behave as neurotoxins by acting on sodium channels.
STEROIDEAL ALKALOIDS (CHARACTERISTICS AND CRUE DRUGS)
Steroidal alkaloids arise by the inclusion of a basic nitrogen atom at some
point in the steroid molecule.
Kurchi, Holarrhena
White Hellebore
Kurchi, Holarrhena
STEROIDEAL ALKALOIDS
Kurchi contains numerous steroidal-type alkaloids (1.8-4.5%)
including conessine used as starting material of some hormones
such as aldosterone.
Antiprotozoal activity. The drug is used as a treatment for amoebic
dysentery.
White Hellebore
STEROIDEAL ALKALOIDS
Alkaloids: jervine, protoveratrine A, protoveratrine B (protoveratrines
are medicinal alkaloids esters of protoverine)
Antihypertensive activity. Narrow therapeutic range.
Solanaceae containing steroidal alkaloids
Many plants in the Solanaceae family accumulate steroidal alkaloids based
on a C27 cholestane skeleton. They are usually present as glycosides which
have as the saponins, surface activity and hemolytic properties.
Nevertheless these compounds are also toxic by ingestion.
Since the production of medicinal steroids from steroidal saponins
requires preliminary degradation to remove the ring systems containing
the original cholesterol side-chain, it is indifferent whether these rings
contain oxygen or nitrogen.
In this sense, plants rich in solasodine or solanidine could also be
employed for commercial steroid production.
Potato and Woody Nighshade
Potato
Solanaceae containing steroidal alkaloids
Solanidine
Woody Nighshade
Solanaceae containing steroidal alkaloids
Toxicity due to soladulcidine and solasodine glycosides