Presented byKIRAN.B

3rd B-pharmaSSCP, Tumkur

Digitalis LeavesFox Glove Leaves

FAMILYScrophulariaceae

Digitalis is a biennial herb grows wild in European countries.

For medicinal purposes, the plant is cultivated in Holland, England, France, Germany & North America.

In India it is cultivated in Kashmir region.

Digitus (Latin)- Finger Purpurea – refers to the purple colour of the flowers.

Digitalis consists of dried leaves of Digitalis purpurea containing not less than 0.3% of total cardenolides calculated as Digitoxin.

After collection, leaves are dried immediately at a temperature not exceeding 60 degree & stored in a moisture proof container, the drug is required to contain not more than 5% of moisture.

General apperance: Usually broken & crumpled

Type: Simple Colour: Dark Greyish-Green Size: 10-40cm long & 4-20cm

wide Base: Tapering,

decurrent(winged petiole) Margin: Crenate or Serrate,

also Dentate Apex: Obtuse or Rounded

Venation:Pinnate venation, prominent on the lower surface & close network of veinlets

Upper surface: Dark green & minutely hairy

Lower surface: Greyish green, very pubescent

Shape: Ovate-lanceolate to broadly ovate

Odour: Characteristic Taste: Bitter

Digitalis mainly contain Cardiac glycosides i.e,Cardenolides (C-23)

Saponin glycosides:Gitonin, Digitonin Digitalis contains 0.2-0.45% mixture of both

primary & secondary cardiac glycosides

(Enzymatic hydrolysis) Primary glycoside Secondary glycoside

(Acid Hydrolysis) Secondary glycoside Aglycone

Digitalis also contains several other glycosides such as Odoroside H, Glucogitaloxin, Gitaloxin, Verodoxin and Glucoverodoxin.

Primary Glycosides Secondary Glycosides Aglycone Purpurea Digitoxin Digitoxigenin glycoside A (EH) +Glucose (AH) +3Digitoxose

Purpurea Gitoxin Gitoxigenin glycoside B (EH) +Glucose (AH) +3Digitoxose

Glucogitaloxin Gitaloxin Gitaloxigenin (EH) +Glucose (AH) +3DigitoxoseEH - Enzymatic Hydrolysis Enzyme:DigipuridaseAH - Acid Hydrolysis The primary glycosides are less absorbed & less stable

than secondary glycosides

Digitalis increases excitability of Cardiac muscles and produces more powerful contractions.

It is effective in Congestive cardiac failure to increase cardiac output and to relieve venous congestion.

Hence it is described as a Cardiotonic.

The improvement of circulation through kidney results in diuresis and loss of edema.

Keller-Kiliani’s Test: Boil 1gm of drug with 70% of alcohol for 2-3min. Filter, to

the filtrate add 10ml of water+0.5ml of strong lead acetate solution. Shake & filter. Filtrate is shaken with chloroform & allow to separate. Chloroform layer is seperated and evaporated gently in porcelin dish. Dissolve the cooled residue in 3ml of glacial acetic acid containing 2 drops of 5% Fecl3. Carefully transfer this solution to 2ml of Con.H2SO4

A reddish brown layer forms at the junction of two liquids, & the upper layer slowly becomes bluish green darkening with standing.

Balget Test: Glycosidal extract+ Sodium picrate Yellow to orange colour Legals Test: The extract is dissolved in pyridine +sodium nitro prusside soln. to make alkaline Pink to Red Keddes Test: Glycoside extract+2% 3,5 dinitro benzoic

acid in methanol+ KOH soln. Blue or violet colour that fades out(Cardenolide aglycone present)

Digitalis lanata

The leaves of Digitalis lanata have 3-4 times greater activity than Digitalis purpurea.

The leaves of Digitalis lanata used as commercial source of the most widely used cardio active glycoside Digoxin.

Wolly fox glove leaf , Austrial Digitalis.

SOURCE These are the dried leaves of Digitalis

lanata, belonging to family Scrophulariacece, & contain 1%-1.4%

of a mixture of cardiac glycosides.

Leaves are sessile, linear lanceolate.

Size: 25-30cm long & 4-5cm wide Margin: Entire Apex : Acuminate

Lanatosides A, B, C & E. lanatosides resembling those of Digitalis purpurea but are acetylated at the Digitoxose moiety adjacent to terminal glucose.

The greater activity of Digitalis lanata is due to Digoxin.

(On hydrolysis) Digoxin Digoxigenin, contain a hydroxy (OH) group in the 12th position.

Mullein Leaves Comfrey Leaves Primrose Leaves

Other species of Digitalis containing Cardiac glycosides

Digitalis scubalpina, Digitalis dubina, Digitalis grandiflora, Digitalis ferruginea, Digitalis mertonensis,,etc

Digitalis purpurea Epidermis: Wavy anticlinal walls. Stomata: Ranunculaceous or anomocytic. CoveringTrichomes: Multicelluar & finely

warty with blunt tips. Certain cells of covering trichomes are collapsed.

Glandular Trichomes: Rare, unicellular & multicellular stalk having unicellular or bicellular head.

Note: Calcium oxalate crystals are absent.

Epidermis: Irregular beaded walls

Stomata: Anomocytic or Ranunculaceous.

Trichomes: very rare

Note: Calcium Oxalate crystals are absent. If covering trichomes are present they are long(10-14 celled) & glandular trichomes with unicellular stalk & bicellular head or multicellular stalk with unicellular head.