Pharmacognosy Questions and Answers

Answer: A

Devil's dung is asafoetida, whose botanical source is Ferula asafoetida.

Asafoetida (hing) is the oleo-gum-resin from the roots and rhizome of Ferula species of the family Apiaceae. Its strong, foul smell comes from sulphur compounds, which gave it the name devil's dung. It is used as a carminative and as a spice.

Rauwolfia serpentina is sarpagandha, the source of reserpine. Datura stramonium is the thorn apple, and Atropa belladonna is deadly nightshade; both contain tropane alkaloids.

Answer: A

The part mainly used is the leaves.

Belladonna leaf (the dried leaves and flowering tops of Atropa belladonna) is the official drug. It contains the tropane alkaloids hyoscyamine and atropine, which are anticholinergic and are used as antispasmodics and to reduce secretions.

Belladonna root is also used and is in fact richer in alkaloids, which makes the root a common trap here, but the leaf is the part the standard pharmacognosy texts give as the main drug. The flowers and seeds are not the drug of commerce.

Answer: A

Eugenia caryophyllus is the botanical name of clove.

Clove is the dried flower bud of the tree now usually called Syzygium aromaticum (family Myrtaceae). Its volatile oil is rich in eugenol, used as a dental analgesic and antiseptic.

Cardamom is Elettaria cardamomum, nutmeg is Myristica fragrans, and cinnamon is Cinnamomum zeylanicum (C. verum), so none of them carries the name Eugenia.

Answer: A

Mulethi is liquorice, Glycyrrihiza glabra (usually spelt Glycyrrhiza glabra).

The dried roots and stolons are used. They contain the sweet saponin glycoside glycyrrhizin, and the drug is used as a demulcent and expectorant, as a flavouring, and in the treatment of peptic ulcer.

The other names belong to different plants: Aloe barbadensis is aloe (ghritkumari), Withania somnifera is ashwagandha, and Ocimum sanctum is tulsi (holy basil).

Answer: B

The laxative drug is senna.

Senna leaves and pods (Cassia angustifolia and C. acutifolia) contain anthraquinone glycosides, the sennosides. Bacteria in the colon release the active aglycones, which stimulate the bowel wall, so senna is a stimulant purgative usually taken at night to act by morning.

Clove and fennel are carminatives, used to relieve flatulence, and clove oil is also a dental analgesic. Ashoka (Saraca asoca) bark is a traditional uterine tonic used for menstrual disorders. None of the three is a laxative.

Answer: D

The inert insoluble residue left after extraction is called marc.

In maceration or percolation, the solvent (menstruum) dissolves the active constituents of the crude drug. The solution obtained is the extract, and the exhausted plant material left behind is the marc, which is pressed to recover the remaining liquid.

A distillate is the condensed vapour collected in distillation. The extract is the useful product, the opposite of the residue. 'Particles' is not a pharmaceutical term for the residue.

Answer: C

Vincristine and vinblastine come from Vinca.

They are alkaloids of the Madagascar periwinkle, Vinca rosea (now Catharanthus roseus). Both bind tubulin and stop the mitotic spindle forming, which halts cell division, so they are used as anticancer drugs: vincristine in leukaemias and lymphomas, vinblastine in Hodgkin's disease and testicular cancer.

Ephedra is the source of ephedrine, ginseng contains ginsenosides, and rhubarb contains anthraquinone purgatives. None of them yields the vinca alkaloids.

Answer: B

Rauwolfia is used as an antihypertensive.

The root of Rauwolfia serpentina (sarpagandha) contains the alkaloid reserpine. Reserpine depletes noradrenaline from sympathetic nerve endings, which lowers blood pressure, and it was once also used as a tranquilliser.

It is not an analgesic, an expectorant or a laxative. Those uses belong to other drugs: opium alkaloids for pain, ipecacuanha or ammonium chloride for expectoration, and senna for constipation.

Answer: A

The scientific name of nutmeg is Myristica fragrans.

Nutmeg is the dried seed of Myristica fragrans (family Myristicaceae), and mace is the dried red aril around the same seed. It is used as a spice, a carminative and a flavouring, and its oil contains myristicin, which is toxic in large doses.

'Frula foetida' (properly Ferula) is asafoetida, Zingiber officinale is ginger, and Piper nigrum is black pepper.

Answer: A

Glycosides are condensation products of sugar + aglycone.

A glycoside forms when a sugar (the glycone) joins a non-sugar part (the aglycone or genin) through a glycosidic bond, with loss of a molecule of water. Acid or enzyme hydrolysis reverses this and releases the sugar and the aglycone. The aglycone usually carries the drug's action, as in the cardiac glycosides of digitalis and the anthraquinone glycosides of senna.

Proteins and fats are not the partners in a glycoside, so the other combinations are wrong.