Glycosides:- Digitalis PDF/ PPT

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Description

Glycosides

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Content

Glycosides

✓ Source, diagnostic characters, constituents, uses, adulterants and

substitutes of Digitalis

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Objectives

• At the end of this lecture, student will be able to

– Discuss the source, diagnostic characters, constituents,

uses, adulterants and substitutes of Digitalis

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Digitalis

Synonym

Digitalis leaf, foxglove leaf

Source

Dried leaves of Digitalis purpurea, dried at temp below 60oC,

immediately after collection, should not contain more than 5 %

moisture

Family

Scrophulariaceae

Geographical source

England, Europe, US, India
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Digitalis
Macroscopy

Colour – Dark greyish green

Odour – Slight

Tatse – Bitter

Size – 10-40 cm in length, 4-20 cm wide

Shape- ovate- Lanceolate to broadly ovate

Margin – Irregularly crenate or serrate or occasionally dentate margin

Venation – Pinnate

Texture – Pubescent

Veinlets prominent in the lower surface

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Digitalis
Microscopy

✓ Dorsiventral

✓ Stomata – Anamocytic

✓ Trichomes

❖ Covering – uniseriate, multicellular (3-5 cells), blunt apex,

(collapsed cell covering trichomes)

❖ Glandular – Unicellular stalk, uni or bicellular head, seen in

veins

✓ Free from calcium oxalate and scelerenchyma

✓ Collenchyma – upper epidermis, lower epidermis, pericycle

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Digitalis
Microscopy

 

Digitalis
Powder characters

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Digitalis
Constituents

✓ Cardiac glycosides – cardenolides

✓ Pupurea glycosides A & B, Glucogitaloxin – primary glycosides

✓ Purpurea glycoside A – Digitoxin + glucose – digitoxigenin + 3 –

digitoxose

✓ Purpurea glycoside B – Gitoxin + glucose – Gitoxigenin + 3 –

digitoxose

Other glycosides

✓ Odoroside H, Gitaloxin, verodoxin, glucoveradoxin

✓ Saponin glycosides

✓ Digitonin, gitonin
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Digitalis
Tests

Keller KIliani test (For digitoxose)

1 gm Drug + 10 ml 70% alcohol, Boil

Filter, to the filtrate add 5 ml water, 0.5 ml strong lead acetate solution

Shake and separate the filtrate

Clear filtrate treated with chloroform and evaporated to dryness

Extract dissolved in glacial acetic acid

Cooled, 2 drops of ferric chloride solution is added

Content transferred to test tube with 2 ml conc, sulphuric acid

Reddish brown layer acquiring bluish green colour after standing – Digitoxose

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Digitalis
Tests

Legal test

Extract dissolved I pyridine, sodium nitro prussiade solution is added,

made alkaline – pink or red colour

Baljet test

Section of digitalis- sodium picrate – yellow to orange

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Digitalis

Assay

✓ Bioassay – IP suggests pigeon or guinea pig

Use

✓ CHF – blocks the Na-K ATPase pump, hence intracellular Na level

increase- leads to increase in Ca ions – protein action is enhanced

(actin, myosin) – forceful contraction of myocardium

✓ Slows ventricular rate in atrial fibrillation, atrial flutter,

supraventricular tachycardia and premature extra systoles

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Digitalis
Adulterants

✓ Verbascum Thapsus – Scrophulariaceae – Candelabra trichomes

✓ Primrose leaves – Primula vulgaris – Primulaceae – uniseriate

covering trichomes (8-9 cells)

✓ Comfrey leaves – Symphytum officinale – Boraginaceae –

Multicellular trichome with hook in top

V. thapsus Pw.w vwu.lDgualroiMs i x .c o m S1. 3officinale

 

Digitalis
Allied drugs

Digitalis lanata – Scrophulariaceae – Wooly fox glove

Constituents

✓ Primary glycosides – Lanotoside A, B, C, D, E (glycone- digitoxose is

acetylated)

Use

✓ Commercial source for digoxin, lanatoside C,

Lanatoside A and mixture of lanatosides

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Digitalis
Allied drugs

Digitalis lutea – Scrophulariaceae – Straw fox glove

✓ Sessile, oblanceolate with serrate or dentate margin

✓ As potent as D. purpurea

✓ Common substitute for official drug

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Digitalis
Allied drugs

Digitalis thapsi –Scrophulariaceae – Spanish fox glove

✓ Small leaves, yellowish green, lanceolate with crenate

✓ Covering trichome absent

✓ Calcium oxalate present

Other species

✓ D. subalpine

✓ D. dubia

✓ D. grandiflora

✓ D. ferruginea

✓ D. mertonensis www.DuloMix.com 16

 

Summary

➢ Digitalis – Digitalis purpurea, dried at temp below 60oC, immediately

after collection, should not contain more than 5 % moisture –

Cardenolides – Purpurea glycoside A & B – Kellerkiliani test – cardio

tonic

➢ Allied drugs include D. lanata, D. lutea, D. thapsi etc

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Thank You
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