ALKALOIDS…..

PRESENTED BY:- SYEDA BISMA.

HAFZA SHAHID.NIMRA MUNIR.

PESENTED TO:-SIR IMRAN.

ALKALOIDS:-

• one of a large group of small organic compounds, mainly derived from amino acids, and containing nitrogen, found in plants. They are water-soluble, usually bitter in taste and are characterized by powerful physiological activity. Examples are morphine, cocaine, atropine, quinine, nicotine and caffeine. The term is also applied to synthetic substances that have structures similar to plant alkaloids, such as procaine. When treated with acids they are converted to water-soluble salts. In cases of poisoning by alkaloids the recommended antidote is tannic acid, but heavy metal salts and iodine also precipitate them. Includes pyrrolizidine and solanaceous alkaloids.

HISTORY OF ALKALOIDS…..

• Among the most notorious poisons in the history of civilization are the alkaloids. Very early in history, human beings learned to exploit these organic compounds for different purposes such as therapeutic treatment, defense, cosmetics, and getting food. They also used alkaloids to murder disagreeable fellow beings. Because they were not aware of the toxic effects of some special alkaloids, the use of these compounds led to small and great disasters.

• During the course of civilization, knowledge of natural plant poisons and, accordingly, knowledge of poisonous plants was lost, especially in towns, which is documented by the increasing number of modern cases of poisoning

OCCURANCE:-

• The number of structurally different alkaloids has been estimated to be 6000. Most of them occur inflora, 1%in ∼animals, and not more than 0.5% in fungi and bacteria.

PHYSICAL AND CHEMICAL PROPERTIES;-

• Although numerous alkaloids exist, they have similar properties when separated. In general, they are colorless, crystalline solids that are basic, have a ring structure, and have definite melting points. They are also derived from plants and have a bitter taste. However, some exceptions are known. For instance, some alkaloids are not basic and others are brightly colored or liquid. Other alkaloids are produced synthetically. Most alkaloids are also chiral molecules, meaning they have non super imposable mirror images. This results in isomers that have different chemical properties. For example, one isomer may have a physiological function while the other does not.

THERAPEUTIC USES:-

• The physiological effects of alkaloids have made them important compounds in medicine. They have been used as painkillers, stimulants, muscle relaxants, tranquilizers, and anesthetics. The four types of alkaloids that have the most important economic impact include opiates, cocaine, caffeine, and nicotine.

Applications of alkaloids:-• Quinine:- • Quinine was purified as early as 1823,

and soon it replaced crude cinchona bark as the standard treatment for malaria. Not until the 1930s was quinine replaced by synthetic analogues that offered fewer side effects and a more reliable supply. Quinine is still used as the principal flavoring agent in tonic water—a beverage named for its ability to prevent malarial symptoms.

• Cinchona bark also produces quinidine. It is used primarily to control abnormalities of heart rhythm such as fibrillation, a series of rapidly quivering beats that do not pump any blood, and heart block, a condition in which electrical currents fail to coordinate the contractions of the upper and lower chambers of the heart.

Vinca alkaloids:-

• Vincaleukoblastine and vincristine, two alkaloids derived from the periwinkle plant (Catharanthus roseus), are used effectively for the treatment of white-blood-cell cancers. Vincaleukoblastine is especially useful against lymphoma (cancer of the lymph glands), while vincristine is used against the most common form of childhood leukemia.

ATROPINE:-

• Atropine is an alkaloid produced by several plants, including deadly nightshade (Atropa belladonna), Jimson weed (Datura stramonium), and henbane (Hyoscyamus niger). It has a variety of medical uses, as it is able to relax smooth muscle by blocking action of the neurotransmitter acetylcholine. Atropine is most commonly used to dilate the pupil.

Pilocarpine:-

• Pilocarpine, derived from several Brazilian shrubs of the genus Pilocarpus, is another alkaloid used in ophthalmology, the medical specialty that treats the eye. This drug stimulates the drainage of excess fluid from the eyeball, relieving the high pressure in the eye caused by glaucoma. If untreated, glaucoma can lead to blindness.

Classification of alkaloids:-They are broadly classified into• Proto or pseudo alkaloids• True or heterocyclic alkaloids• Pseudo alkaloids• The examples for pseudo alkaloids are ephedrine, colchicines, aconitine etc• True alkaloids• They are again subdivided into• Indole alkaloids eg. Strychnine, reserpine, ergotamine.• Steroidal alkaloids e.g. Conicine, withanine.• Quinoline alkaloids eg.quinine, quinidine.• Pyridine alkaloids e.g. Trigonelline.• Pyrrolidine alkaloids e.g. nicotine• Tropane group e.g. Atropine, cocaine• Iso-quinoline group e.g. Papaverine, narcine, berberine.• Phenanthrene group e.g. Morphine, codeine.• Phenethylamine group eg.ephedrine• Purine group etc eg caffeine• Other than these there are quaternary ammonium compounds like choline, neurine, muscharine.

General scheme:-(extraction of alkaloids)

• Weighing.

• Soaking in alcohol.

• Boiling in water.

• Extraction using soxhelet principle.

• Identification test applied.

Weighing:-

• First of all an accurate amount of drug is weighed.

• Soaking:-

• Then soaked in 0.1NAcOH for 2HOUR.

• BOILING:-

• THEN BOILED IN WATER FOR 0.5 HOURS

Extraction:-

• Experimental conditions are worked out on a laboratory scale for the removal of alkaloids from seeds of bitter Peruvian lupin, Lupinus mutabilis. Four trials were carried out in this study using dilute aqueous solutions of HC1 and AcOH, and water. A simple und quick procedure is recommended for the removal of alkaloids from the whole seeds. The seeds are first soaked in 0.1N AcOH for 2hr, then boiled in water for 0.5hr, and eventually extracted with water for 8hr following the Soxhlet principle. More than 95% of the alkaloids are extracted by this procedure without leading to environmental pollution. The debittered whole seeds have a bland taste and contain around 50% protein and 20% fat Following Soxhlet extraction, the alkaloids are easily obtained as a side product.

PURIFICATION OF ALKALOIDS:-

• An efficient method for purification of alkaloids.By using HPLC purification is done, featuring a polar-copolymerized stationary phase named C18HCE. As ionizable solutes, the crude alkaloid sample often suffered from serious peak tailing problem on conventional RP-LC columns, and the separation would rapidly became destroyed with the increasing of load amount. However, on the new stationary phase, good peak shapes (asymmetry factor <1.5) as well as good loadability were easily obtained in a commonly used acidic mobile phase condition. The loading amount could reach 10 mg per injection on an analytical C18HCE column for laboratory-scale purification. About 6.8 mg of palmatine (HPLC purity >98%) and 44.4 mg of dehydrocorydaline (HPLC purity >98%) were rapidly derived from 200 mg of the crude alkaloid sample, and the recoveries of these two compounds were 76.5 and 81.7%, respectively. The purified alkaloids were characterized by comparing retention times with standard compounds as well as (1)H-NMR data. The new method is simple and high yielding, and it may provide a promising tool for purification of alkaloids as well as other alkaline compounds.

EXTRACTION OF ALKALOIDS:-

• EXTRACTION OF ALKALOIDS FROM MUSHROOMS:-

IDENTIFICATION OF ALKALOIDS:-

• 1. Brown – Ring Test :• It is used for chemical analysis

of nitrates in which the solution to be tested is mixed with iron sulphate solution in a test tube and concentrated H2SO4 (sulphuric acid) is carefully poured along the side of the test tube.

• In nitrate containing substances a brown ring is formed where the layer of acid touches the solution (FeNO)SO4

FLAME TEST:-• It is used to identify certain

elements in which a clean platinum wire is dipped into the mixture to be tested and the wire is heated using a busen flame.

• The presence of certain elements can be detected by the change in the colour of flame.

• For example, a brilliant organe – yellow will indicate sodium; crimson, strontium; and apple green barium.

BEILSTEIN’S TEST:-

It is used for the detection of halogen in an organic compound in which a clean copper wire is heated in an oxidizing flam till the flame is no longer green.

• The wire is then dipped in a solution of the substance to be analyzed and heated again. If CI, Br or I is present the flame turns a bright green.

FEHLING’S TEST:-

• It is used to detect sugars and aldehydes in a solution. Equal amounts of solution of copper sulphate (Fehling A) and sodium tartrate (Fehling B) are mixed in a test tube, On boiling this with a given solution a red precipitate forms is sugar or aldehyde is present.

MOLISCH’S TEST:-

• 6. Molish’s Test :• It is used to detect

carbohydrates in a solution. The solution to be tested is mixed with a small quantity of alcoholic alphanaphthol and concentrated sulphuric acid is slowly poured down the side of the test tube.

When the two liquids meet the formation of deep violet rings indicates presence of carbohydrate.

RAST’S METHOD:-

• It is used to determine molecular weight by measuring the depression of freezing point of a camphor by a known weight of the solute.

SCHIFF’S TEST:-• It is used to distinguish between

aldehydes and ketones. An aqueous solution of resoniline and sulphurous acid (Schiff’s reagent) is used to test for the presence of aldehydes, which oxidize the reduced from of the dye rosaniline backIt is used to distinguish between aldehydes and ketones. An aqueous solution of resoniline and sulphurous acid (Schiff’s reagent) is used to test for the presence of aldehydes, which oxidize the reduced from of the dye rosaniline back to its original magenta colour.

• The aldehydes restore the colour immediately whereas ketones, restore the colour slowly. to its original magenta colour.

• The aldehydes restore the colour immediately whereas ketones, restore the colour slowly.

“THANKYOU”