Aporphine alkaloids
All the aporphine alkaloids are based on the 4Hdibenzo quinoline structure or its 3-methyl
derivative commonly known as the aporphine
nucleus. The numbering system is as
indicated, so as to conform with the "Ring
Index"
Glaucine
This widely occurring alkaloid has now been
reported in Glaucium flavum (yellow horned
poppy), and other plants.
In mammals, glaucine produces slight narcosis
(‫ )ذهول‬followed by convulsions, and is
depressant to the heart and striated muscles .
Glaucium flavum (yellow horned poppy)
Glaucium flavum (yellow horned poppy) is a summer flowering plant
in the Papaveraceae family, which is native to Northern Africa,
Micronesia, temperate zones in Western Asia and the Caucasus, as
well as Europe. Habitat: the plant grows on the seashore and is
never found inland. All parts of the plant, including the seeds, are
toxic and can produce a range of symptoms up to and including
respiratory failure resulting in death FDA poisonous plants
database. It is a noxious weed(‫ )أعشاب ضارة‬in some areas of North
America.
Laurolitsine)Norboldine(
Laurolitsine has been isolated from the leaves of
Neolitsea sericea and the root, bark, and wood of
Litsea japonica . It is an amorphous powder which
can be characterized as the picrolonate, m.p. 239'
dec., or the picrate salt, m.p. 212' dec. The
alkaloid has two methoxyl and two hydroxyl
groups, and in addition possesses a secondary
aliphatic amine function as indicated by a positive
Feigl test. Laurolitsine exhibited potent
cytotoxicity towards pancreatic cancer cell line
Laurolitsine
Litsea japonica
Litsea is a genus trees or shrubs belonging to the Laurel family,
Lauraceae. The genus includes 200 to 400 species in tropical and
subtropical areas of both hemispheres. Trees or shrubs, dioecious.
The leaves can be either deciduous or evergreen depending on
species, and aromatic. The flowers are from greenish to white,
greenish-yellow, yellowish
Bulbocapnine
• Bulbocapnine is an alkaloid found in Corydalis cava
(Papaveraceae) and Dicentra, plants in the family
Fumariaceae that can cause fatal poisoning in sheep
and cattle. It has been shown to act as an
acetylcholinesterase inhibitor, and inhibits biosynthesis
of dopamine via inhibition of the enzyme tyrosine
hydroxylase.
• It "inhibits the reflex and motor activities of striated
muscle. It has been used in the treatment of muscular
tremors and vestibular nystagmus". The psychiatrist
Robert Heath carried out experiments on prisoners at
the Louisiana State Penitentiary using bulbocapnine to
induce stupor.
Bulbocapnine
Corydalis cava (Papaveraceae)
Nor-lupinane (Quinolizidine) Alkaloids
Quinolizidine alkaloids are a widely distributed, heterogeneous
group of alkaloids having known toxicity to humans and domestic
animals. Plants containing quinolizidine alkaloids with known
toxicity include the following:
• Baptisia species (false indigo)
• Cytisus species (scotch broom)
• Laburnum species (goldenchain, laburnum)
• Lupinus species (lupine, bluebonnet)
• Sophora species (mescal bean, frijolito)
Quinolizidine
Cytisine
Cytisine, also known as baptitoxine and sophorine, is a toxic alkaloid that
occurs naturally in several plant genera, such as Laburnum and Cytisus of
the family Fabaceae. Despite its toxicity (LD50 i.v., in mice ~2 mg/kg), it
has been used medically to help with smoking cessation: recent clinical
trials have shown cytisine to be more effective than conventional
smoking cessation aids and it is much cheaper than similar products. Its
molecular structure has some similarity to that of nicotine and it has
similar pharmacological effects. Excessive doses can interfere with
breathing and cause death. their stimulant effects and mild
hallucinogenic properties.
Mescal bean may have been used by Native American peoples for
ceremonial and medicinal purposes. Sophora root is used in traditional
Chinese medicine where it is known as "Ku Shen" and is used to treat
dysentery, scabies, itchy rashes such as with eczema, skin lesions,
jaundice, edema, urinary dysfunction, and vaginal discharge
Cytisine
Mescal bean
Sparteine
Sparteine is a lupin alkaloid containing a tetracyclic bis-quinolizidine
ring system derived from three C5 chains of L-lysine. It is a
antiarrhythmic agent; a sodium channel blocker. It is an alkaloid
and can be extracted from scotch broom. It is the predominant
alkaloid in Lupinus mutabilis, and is thought to chelate the
bivalents calcium and magnesium. It is not FDA approved for
human use as an antiarrhythmic agent.
It is also used as a chiral base in organic chemistry, and as a ligand in
an inorganic chemical synthesis.
Scotch Broom
Indolizidine Alkaloids
The indolizidine alkaloids can be divided into two
major groups, the phenanthroindolizidines from the
Asclepiadaceae and Moraceae families and the
simpler indolizidines from all other sources.
Indolizidine Nucleous
PHENANTHROINDOLIZIDINE ALKALOIDS
Phenanthroindolizidines are a series of plant-derived natural
alkaloids primarily found in the Asclepiadaceae and
Moracea plant family.
R-tylophorine, R-antofine, and R-cryptopleurine are well
known representatives in the family having been reported
to have potent antitumor activity. Phenanthroindolizidine
alkaloids have been isolated from only two plant families.
Their presence has been established in several species of
five genera, Tylophora, Cyanchum, Vincetoxzcum,
Pergularza and Antitoxzcum among the more than 300
genera of the Asclepiadaceae family and in one species of
the genus Ficus of the Moraceae family. A major side effect
of these natural alkaloids impacting their use as
therapeutic agents is their severe CNS toxicity.
Tylophorine
Tylophorine, a phenanthraindolizidine alkaloid
isolated from Tylophora indica exerts antiangiogenic
and antitumor activity by targeting vascular
endothelial growth factor receptor 2-mediated
angiogenesis, thus may be a viable drug candidate
in anti-angiogenesis and cancer therapy
Tylophorine
(R)-antofine
R-cryptopleurine
Imidazole Alkaloids
alkaloids containing the imidazole nucleus.
• the smallest group in terms of structure numbers, which are formed by
precursors derived directly from the amino acid L-histidine.
•
L-histidine.
imidazole nucleus
Pilocarpus alkaloids
Chemically, the majority of Pilocarpus alkaloids hold
simultaneously an imidazole and a γ-lactone ring.
Pilocarpine was first isolated, in 1875, by Hardy and by
Gerrard, in distinct works, as colourless crystalline
salts from P. jaborandi Holmes leaves . This alkaloids
is also found in several other species such as P.
microphyllus Stapf.,where total pilocarpine content
range from ca. 3.0 to 70% of total alkaloids.
Isopilocarpine is the epimerization product of
pilocarpine produced by enolization pathway.
Pilocarpine
Pilocarpine is a drug used to treat dry mouth (xerostomia) and
glaucoma. It is a parasympathomimetic alkaloid obtained
from the leaves of tropical American shrubs from the genus
Pilocarpus. It is a non-selective muscarinic receptor agonist
in the parasympathetic nervous system, which acts
therapeutically at the muscarinic acetylcholine receptor M3
due to its topical application, e.g., in glaucoma and
xerostomia.
It is on the World Health Organization's List of Essential
Medicines, a list of the most important medication needed
in a basic health system.
Pilocarpine stimulates the secretion of large amounts of saliva
and sweat.
Pilocarpine
Histamine
• Histamine is a biogenic amine formed by Lhistidine decarboxylation mediated by HDC
(histidine decarboxylase) and naturally occurs in
some fungi, marine and plant species. It was
isolated from aerial parts of Capsella bursapastoris L. (Brassicaceae), Lolium perenne L.
(Poaceae)
and
Spinacea
oleracea
L.
(Chenopodiaceae). This amine may act as an
intermediate in many imidazole derivatives
biosynthesis such as amides.
Histamine involved in local immune responses as well as regulating
physiological function in the gut and acting as a neurotransmitter.
Histamine is involved in the inflammatory response. As part of an
immune response to foreign pathogens, histamine is produced by
basophils and by mast cells found in nearby connective tissues.
Histamine increases the permeability of the capillaries to white
blood cells and some proteins, to allow them to engage pathogens in
the infected tissues
Histamine
Purine (Xanthine) Alkaloids
The purines are consisting of a six-membered pyrimidine ring fused to
a five-membered imidazole ring. The pharmaceutically important
bases of this group are all methylated derivatives of 2,6 dioxy-purine
(Xanthine). This group includes mainly Caffeine, theobromine and
theophylline alkaloids. These alkaloids are weak bases, they give no
precipitate with Mayer's reagent.
Purine
Xanthine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid and a stimulant
drug. Caffeine is found in varying quantities in the seeds, leaves, and
fruit of some plants, where it acts as a natural pesticide that
paralyzes and kills certain insects feeding on the plants, as well as
enhancing the reward memory of pollinators. It is most commonly
consumed by humans in infusions extracted from the seed of the
coffee plant and the leaves of the tea bush, as well as from various
foods and drinks containing products derived from the kola nut.
Other sources include yerba mate, guarana berries, guayusa, and the
yaupon holly.
In humans, caffeine acts as a central nervous system stimulant,
temporarily warding off drowsiness and restoring alertness. It is the
world's most widely consumed psychoactive drug, but unlike many
other psychoactive substances, it is legal and unregulated in nearly all
parts of the world. Beverages containing caffeine, such as coffee, tea,
soft drinks, and energy drinks, enjoy great popularity.
Caffeine
Theobromine
Theobromine, is a bitter alkaloid of the cacao plant, with the chemical formula. It
is found in, chocolate as well as in a number of other foods, including the
leaves of the tea plant, and the kola (or cola) nut. It is classified as a xanthine
alkaloid. Despite its name, the compound contains no bromine—theobromine
is derived from Theobroma, the name of the genus of the cacao tree, (which
itself is made up of the Greek roots theo ("God") and broma ("food"), meaning
"food of the gods") with the suffix -ine given to alkaloids and other basic
nitrogen-containing compounds. Theobromine is a slightly water-soluble
(330 mg/L), crystalline, bitter powder. Theobromine is white or colourless, but
commercial samples can be yellowish. It has a similar, but lesser, effect to
caffeine in the human nervous system, making it a lesser homologue.
Theobromine is an isomer of theophylline, as well as paraxanthine.
Theobromine is categorized as a dimethyl xanthine. In modern medicine,
theobromine is used as a vasodilator (a blood vessel widener), a diuretic
(urination aid), and heart stimulant.
Theobromine
Theophylline
Theophylline, also known as 1,3-dimethylxanthine, is a methylxanthine drug
used in therapy for respiratory diseases such as COPD(Chronic obstructive
pulmonary disease) and asthma under a variety of brand names. As a
member of the xanthine family, it bears structural and pharmacological
similarity to caffeine. The main actions of theophylline involve:
• relaxing bronchial smooth muscle
• increasing heart muscle contractility and efficiency
• increasing heart rate
• increasing blood pressure
• increasing renal blood flow
• anti-inflammatory effects
• central nervous system stimulatory effect mainly on the medullary
respiratory center
Theophylline
Coffee Tree
Cacao Tree
STEROIDAL ALKALOIDS
steroid nucleus
Classification
Steroidal alkaloids may be divided into three groups on the basis of
botanical source:
(a)solanum alkaloids, obtained from S. tuberosum (potato), S.
lycopersicum (tomato), and other species ;
(b) veratrum alkaloids usually from V. album and V. viride (European
and American “ hellebore ”) or from sabadilla (V. sabadilla) seeds ;
(c) kurchi or holarrhena
alkaloids from ‘‘ kurchi ” (H. antidysenterica), a small Indian shrub, and
from other Indian and African species of Holarrhena.
All the kurchi alkaloids of well-authenticated structure contain a
carbon framework of twenty-one atoms similar to that of the steroid
hydrocarbon pregnane ; owing however to the presence of N-methyl
groups the number of carbon atoms in the molecules of these
alkaloids may rise to twenty-four (the alkaloid conkurchinine may
contain twenty-five carbon atoms in the molecule.
a)solanum alkaloids
α-chaconine and α-solanine, derived from the aglycone solanidine,
solanidine
The sugar portion of these glycoalkaloids hydrolyses in the body,
leaving the solanidine portion
Solanine
Solanine is a glycoalkaloid poison found in species
of the nightshade family (Solanaceae), such as
the potato (Solanum tuberosum) and the tomato
(Solanum lycopersicum). It can occur naturally in
any part of the plant, including the leaves, fruit,
and tubers. Solanine has fungicidal and pesticidal
properties, and it is one of the plant's natural
defenses. Solanine was first isolated in 1820 from
the berries of the European black nightshade
(Solanum nigrum), after which it was named.
Solanine
Solanine poisoning
Solanine poisoning is primarily displayed by gastrointestinal and
neurological disorders. Symptoms include nausea, diarrhea,
vomiting, stomach cramps, burning of the throat, cardiac
dysrhythmia, nightmare, headache and dizziness. In more severe
cases, hallucinations, loss of sensation, paralysis, fever, jaundice,
dilated pupils, hypothermia and death have been reported.
Ingestion of solanine in moderate amounts can cause death. One study
suggests that doses of 2 to 5 mg per kilogram of body weight can
cause toxic symptoms, and doses of 3 to 6 mg per kilogram of body
weight can be fatal. Symptoms usually occur 8 to 12 hours after
ingestion, but may occur as rapidly as 30 minutes after eating highsolanine foods. Solanum glycoalkaloids can inhibit cholinesterase,
disrupt cell membranes, and be teratogenic (cause birth defects).
Chaconine
α-Chaconine is a steroidal glycoalkaloid that
occurs in plants of the Solanaceae family. It is
a natural toxicant produced in green potatoes
and gives the potato a bitter taste. Tubers
produce this glycoalkaloid in response to
stress, providing the plant with insecticidal
and fungicidal properties
Tomatidine
It is obtained from the roots of Rutgers tomato
plant [Lycopersicon esculentum Mill., cultivar.
“Rutgers”] (Solanaceae).
Identification Test Its hydrochloride derivative
(C27H45NO2.HCl) is obtained as crystals from
absolute ethanol having mp 265-270°C and
[α ]D25 -5o (methanol).
b)Veratrum Alkaloids
Veratridine
Veratridine is a steroid-derived alkaloid from
plants in the Liliaceae family that functions as
a neurotoxin by abolishing inactivation of
sodium ion channels. It is primarily obtained
from the herb Veratrum and sabadilla seeds
It is used in ointments for the treatment of
neuralgia and rheumatoid pain
Veratridine
Jervine
it is a teratogen implicated in birth defects when
consumed by animals during a certain period
of their gestation.
c) Alkaloids from ‘‘ kurchi
The plant Holarrhena antidysenterica Linn. is
commonly known in India as , Kurchi.
Kurchi
Conessine
Conessine is a steroid alkaloid found in a number of plant
species from the Apocynaceae family, including
Holarrhena antidysenterica. several of which are used
in traditional herbal medicine as a treatment for
amoebic dysentery. It acts as a histamine antagonist.
The following two alkaloids in high dilutions, kill Paramecia, Colpidia
and Daphnia
conkurchine
holarrhenine