24 Questions
What type of nucleus do the alkaloids in Solanaceous leaves belong to?
Tropane
What is the effect of atropine on the pupil of the eye?
Dilation
What is the characteristic shape of the head of glandular trichomes in Solanaceous leaves?
Club-shaped
What is the therapeutic use of Solanaceous alkaloids as a cough medication?
Sedative
What is the characteristic type of stomata present in Solanaceous leaves?
Anisocytic
What is the characteristic type of crystals present in Solanaceous leaves?
Calcium oxalate
What is the therapeutic use of Solanaceous alkaloids as an antispasmodic?
Relieving muscle cramps
What is the characteristic type of trichomes present in Solanaceous leaves?
Glandular
What is the primary effect of alkaloids on the body?
Decrease body secretions
What is the purpose of using alkaloids as pre-operative medication?
To decrease body secretions
What is the purpose of Mayer's test?
To identify general alkaloids
What is the result of adding potassium-mercuric iodide to the filtrate in Mayer's test?
A white precipitate is immediately formed
What is the purpose of Vitaly's test?
To identify solanaceous alkaloids
What is the result of adding alcoholic KOH solution to the residue in Vitaly's test?
A violet color is produced
What is the active constituent of Belladonna leaf?
Alkaloids, mainly hyoscyamine
What is the use of atropine and hyoscine in ophthalmic practice?
To dilate the pupil of the eye
What is the main characteristic of idioplasts?
They differ from ordinary cells in either form, size or content
What is the main active constituent of Datura stramonium?
Alkaloids, mainly hyoscyamine and hyoscine
What is the use of hyoscine in medicine?
It has a sedative action and is used in motion sickness
What is the characteristic of epidermal cells in the powder of Datura stramonium?
They have a wavy wall and showing stomata of anisocytic type
What is the characteristic of glandular hairs in the powder of Datura stramonium?
They are clavate and have a one or two-celled stalk
What is the characteristic of crystal layer in the powder of Datura stramonium?
Each cell contains a cluster crystal of calcium oxalate
What is the similarity between Hyoscyamus muticus and Datura stramonium?
They resemble each other in action but Hyoscyamus muticus is somewhat weaker
What is the characteristic of epidermal cells in the powder of Hyoscyamus muticus?
They have a striated cuticle and stomata of anisocytic type
Study Notes
Solanaceous Leaves
- Solanaceous leaves come from plants such as Atropa belladonna (Belladonna), Datura stramonium (Thorn apple), Hyoscyamus muticus (Egyptian Henbane), and Hyoscyamus niger (European Henbane).
Histological Characters
- Presence of anisocytic stomata
- Presence of multicellular, uniseriate, 3- to 5-celled covering trichomes
- Presence of glandular trichomes, each with a short or long stalk and a multicellular, club-shaped head (clavate)
- Presence of calcium oxalate crystals, which are of different and characteristic types for the individual leaves
Active Constituents
- Solanaceous leaves contain a group of alkaloids belonging to the tropane nucleus, including:
- Atropine
- Hyoscyamine
- Scopolamine (Hyoscine)
Therapeutic Effects (Uses)
- Solanaceous alkaloids possess a variety of therapeutic uses that include:
- Dilating the pupil of the eye (Mydriatic effect)
- Internally, as a cough sedative and antispasmodic
- Possessing parasympatholytic properties (decrease the body secretions), so they are used as pre-operative medication
- Externally, as a local anaesthetic to relieve pain
Chemical Identification
- Mayer's Test (General Test for Alkaloids): a white precipitate is immediately formed when 0.2 g of powdered Belladonna leaf is shaken with 2 mL of dilute HCl and then a drop of potassium-mercuric iodide (Mayer's reagent) is added
- Vitaly's Test (Special Test for Solanaceous Alkaloids): a yellow solution is produced when 1 g of powdered Belladonna leaf is boiled with 10 mL of dilute HCl, and then a violet color is produced when two drops of alcoholic KOH solution are added to the residue.
Belladonna Leaf
- Plant Source: Dried leaves with or without the flowering tops of Atropa belladonna (Family: Solanaceae)
- Active Constituents: Alkaloids, mainly hyoscyamine, small amounts of hyoscine and little or no atropine
- Uses: As antispasmodic and cough sedative, decreasing body secretions, and used as pre-operative medication
Stramonium Leaf
- Plant Source: Dried leaves with or without the flowering tops of Datura stramonium (Family: Solanaceae)
- Active Constituents: Alkaloids (0.26-0.45%), mainly hyoscyamine and hyoscine, and atropine may be formed from racemization of hyoscyamine
- Uses: Hyoscine has sedative action and is used in motion sickness, atropine is used in ophthalmic preparations to dilate the pupil of the eye, and as antispasmodic in colic.
Hyoscyamus muticus (Egyptian Henbane)
- Plant Source: Dried leaves and flowering tops of Hyoscyamus muticus (Family: Solanaceae)
- Uses: Resembles Belladonna and Stramonium in action but is somewhat weaker
This quiz covers the histological characteristics of Solanaceous leaves, including Atropa belladonna, Datura stramonium, and Hyoscyamus species. Learn about the presence of anisocytic stomata, multicellular covering trichomes, and glandular trichomes.
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