Chemistry of alkaloidNORSYAMIMI BT CHESULAMAN (153504) NUR FATIHAH BT ABAS (154120) G4NURUL FADZILLAH BTMOHD HATA (152266) NOR HIDAYAT BT YUSOF (152356)
INTRODUCTION• Alkaloid~ an example of secondary metabolites• Naturally occurring organic compounds containing nitrogen moiety, and are usually heterocyclic in nature.• Contains nitrogen ~ usually derived from an amino acid.• Normally have a significant physiological action on humans and animals.
CHARACTERISTICS OF ALKALOIDS• Basic in nature due to the presence of nitrogen in their ring• Mostly obtained from plant materials.• Have bitter tasting.• Give a precipitate with heavy metal iodides• Have high pharmacological and physiological activities.
Quinine •an antipyretic alkaloid •Functional groups present in quinine are: methoxy –OCH3, hydroxyl –OH, tertiary amine group, and etcCocaine •obtained from coca leaves. •highly narcotic. •stimulates the central nervous system i.e. CNS depressant. •can lead to psychiatric problem when taken in high dose or when addicted to it.Caffeine •obtained from tea leaves. •also a strong stimulant which can increases alertness, thereby causing insomnia when the body gets addicted.
Occurrence of Alkaloids• Occur in bacteria (Pseudomonas aeruginosa) and rarely in fungi (pscilocin from hallucinogenic mushrooms).• Some alkaloids occur in several genera from different species (caffeine), but most occur in closely related species.• Some occur in certain families (hyoscyamine), while others occur only in a specific species (morphine).• Rarely do plants contain more than 1 type of alkaloid.• All alkaloids of one plant will have a common biogenenetic origin
• Alkaloids occur in all plant parts, but are usually localized in one organ (e.g. the bark or seeds).• Within the plant, [alkaloid] can vary widely from part to part – some parts may contain no alkaloids.• Occasionally, different alkaloids also form in different parts of the plant.• Alkaloid concentrations occur in wide ranges – e.g. Madagascan periwinkle contains 3g per (anti- cancer) alkaloids per tonne of leaves.
Classification of alkaloids Alkaloids have a large variety in their botanical & biochemical origin, in chemical structure and pharmaceutical action. Therefore, like flavonoids, a range of different classification systems exist for grouping alkaloids. They can therefore be classified according to their• Biological origin• Chemical structure - 2 divisions • i. Atypical/non-heterocyclic alkaloids (protoalkaloids or biological amines) • ii. Typical/heterocyclic alkaloids (divided into 14 groups according to their ring structure)• Biosynthetic pathway
Classification of alkaloids• Terpenoid Indole Alkaloids• Benzylisoquinoline Alkaloids• Tropane Alkaloids• Purine Alkaloids• Pyrrolizidine Alkaloids• Other alkaloids: Quinolizine, Steroidal glycoalkaloids
Terpenoid Indole Alkaloids• Large group of about 3,000 compounds• Indole moiety provided by Tryptamine (derived from Tryptophan) and a Terpenoid component• Moneterpenenoid indole alkaloid:• the iridoid glycoside secologanin (derived from the monoterpene Geraniol) and Tryptamine
Benzylisoquinoline Alkaloids• A large and diverse class present in a range of plant families.• The first biosynthetic step is decarboxylation of Tyrosine by Tyrosine Decarboxylase (TYDC) to form Tyramine.• Coupling of two Tyramine derivatives yields (S)- Norcoclaurine.• Norcoclaurine is the precursor of several thousand benzylquinoline alkaloids.
Tropane Alkaloids• Plants containing these alkaloids have been used throughout history as poisons, but many of the alkaloids do have valuable pharmaceutical properties.• Known to be present in the Solanaceae family• The TA Cocaine was found in very small amounts in the original Coca-Cola formula, but was not the main concern of the USDA at the time. Caffeine was considered to be the major problem with the drink. Cocaine
Purine Alkaloids• Caffeine the most important example in coffee, tea, mate, cacao, camellia.• Purine alkaloid biosynthesis starts with xanthosine, a nucleotide degradation product.
Pyrrolizidine Alkaloids• The leading plant toxins.• Over 360 different structures, found in 3% of the world flowering plants.• Primarily restricted to; Boraginaceae, Asteraceae, Fabaceae, and Orchidaceae.• Most of them are esters of basic alcohols known as necine bases.
Alkaloids in modern medicineAtropine-antidote to nerve gas poisoning Codeine, Morphine -Analgesic (painkiller)
Alkaloids in modern medicine Sanguinarine Antibacterial showingCaffeine-central nerve anti plaque activity, used system stimulant in toothpastes and oral rinses Quinine-anti malarial, facilitated exploration of the tropics
Biosynthesis of morphineMORPHINE CODEINE•Obtained from the opium •Occur naturally whichpoppy Papaver somniferum. simply the methyl ether of• used in medical field for morphine and converted torelief the pain since early morphine in the body1500s. •Used in prescription cough medicines and as analgesic. HEROIN •Does not occur naturally but synthesized in laboratory by diacetylation of morphine.