PCOG LEC M5 Glycosides - Cardiac Glycosides (Theoretical)

Cardiac Glycosides

This type of glycoside displays powerful action on the cardiac muscle: increase muscle contractility or tone of cardiac muscle

Cardenolides

Type of cardiac glycoside that is C23 steroid, and 5 member lactone ring

Cardenolides

What type of cardiac glycoside is digitoxigenin

Bufanolides or bufadienolides

Type of cardiac glycoside that is C24 steroid, and 6 member lactone ring.

Bufanolides or bufadienolides

What type of cardiac glycoside is scillarenin

Four sugar units

The sugar moieties of cardiac glycosides, attached to the aglycone by a C-3, β-linkage, are composed of up to _______ sugar units which may include glucose or rhamnose together with other deoxy-sugars whose natural occurrence is, to date, known only in association with cardiac glycosides

Digitoxose and Cymarose

Examples of deoxy-sugars found in cardiac glycosides

Cardiotonic

The genins of all cardiac glycosides are steroidal in nature, that act as __________ agents

Increasing

Cardiac glycosides are characterized by their highly specific action cardiac muscle: (increasing/decreasing) tone, excitability and contractility of this muscle, thus allowing the weakened heart to function more efficiently

Cardenolides

Cardiac glycosides 5-membered lactose ring in position C-17 are known as

digitalis and strophanthus group

Cardenolides are represented by the _____ and _______ groups

Pigeons

Most sensitive animal used in the assay of cardiac glycosides

Digoxin has an OH Group in R3 Position

Differentiate structure of digoxin and digitoxin

Methyl group (CH3)

Digitalis glycosides have a ___________ group in their R chain

Aldehyde group (CHO) or Hydroxyl group (CH2OH)

Strophanthus glycosides have a ___________ group or __________ group in their R chain

Digitalis glycosides

These Cardenolides contain angular methyl group at C-10

Strophanthus glycoside

These cardenolides are characterized by presence of either an aldehydic (CHO) or primary alcoholic (C`H2OH) group at C-10.

Cymarose, K-strophanthidin

Cymarin hydrolysis yields _______

Cymarose, Beta-glucose, K-strophanthidin

K-strophanthin B hydrolysis yields ______

Cymarose, Beta-glucose, Alpha-glucose, K-strophanthidin

K-strophanthoside hydrolysis yields ______________

Ouabain

The seeds of Strophanthus gratus contains another glycoside named

G-strophanthin

Ouabain is also known as ________

Ouabagenin, rhamnose

Ouabain yields ___________ upon hydrolysis

Bufadienolides

Cardiac agents that have doubly unsaturated 6- membered lactone ring in position C-17 are referred to as ___________________

Bufadienolides

This group includes the squill glycosides and the toad venom, bufotoxin

Squill glycosides

Bufadienolides that have a hydroxyl group (OH) at R1 and hydrogen at R2

Bufotoxin

Bufadienolides that have an ester group at both the R1 and R2

Scillaren A

the most important constituent of squill

Scillaridin A

Aglycone of scillarins

Rhamnose, Scillaridin A

Proscillaridin A hydrolysis yields ______

Glucose, Rhamnose, Scillaridin A

Scillaren A hydrolysis yields _______

2 Glucose, Rhamnose, Scillaridin A

Glucoscillarin A hydrolysis yields _______

Alcohol and Aldehyde

The presence of __________ and ___________ in cardiac glycosides makes them prone to hydrolysis, making it hard to isolate pure compounds

chloroform and ethylacetate

Cardiac glycosides are usually soluble in water or aqueous alcohol and insoluble in the fat solvents with exception of ____________ and _______________

Greater solubility in water; lesser solubility in chloroform

The higher number of sugar units in the molecule, the (greater/lesser) solubility in water and (higher/lower) solubility in chloroform

Alcohol

It is a good solvent for both the glycosides and the aglycones; Solvent of choice for the extraction of all CG from drugs.

Petroleum ether and ether

These are used for defatting process of drug, they do not dissolve CG

Acid hydrolysis

This reaction cleave the cardiac glycosides into aglycones and sugar residues

Less sugar units

Specific enzyme usually coexist with CG in plants, which may split the primary G into G with (less/more) sugar units. Thus, CG deteriorate during drying and storage unless special precautions are taken

Cardiotonic, CHF, rheumatic heart disease, atherosclerosis, HTN; Diuretics

Medical importance of Cardiac Glycosides

200μg/tablet

Digitoxin tablet doses accdng to BP/USP

0.0025% digoxin

Digoxin content of digoxin injections accdng to BP/USP

250μg/tablet

Digoxin tablet doses accdng to BP/USP

Cucurbitaceae (pepos)

Bitter glycosides are usually acquired in what plant family -________

Bitter glycosides

Glycosides with bitter taste, also referred to as "bitter principle", "Bitter Tonic)

Bitter glycosides

Complex organic compounds containing lactone ring, soluble in water and very bitter in taste even in much diluted solutions

Increase

Bitter glycosides (decrease/increase) the secretions of GIT by reflex action and are used as stomachic, febrifuge and bitter tonic

Gentiopicrin and amarogentin

Bitter glycosides from Gentian root and Chirata

Picroside and kutkoside

Bitter glycosides from Picrorrhiza

Andrographolides

Bitter glycosides from kalmegh

Quassin

Bitter glycosides from Quassia wood

Cucurbitacins

Bitter glycosides present in Cucurbitaceae

Keller Killiani, Liebermann Burchard, Kedde test

Tests for Cardiac Glycosides (3)

2-deoxy sugar

Keller Killiani is a test for the presence of _________

Steroid

Liebermann Burchard is a test for the presence of __________

unsaturated lactone

Kedde test is a test for the presence of __________

reddish brown color turn to blue purple

Keller Killiani positive result

blue green to pink purple or violet

Liebermann Burchard positive result

purple

Kedde test positive result

Dried, fleshy, inner scales of the bulb

Part of squill that is medically important

Seed

Part of Strophantus gratus that is medically important

Dried Rhizomes and Roots

Part of Black Hellebore/Christmas rose that is medically important

Dried rhizomes and roots

Part of Black Indian Hemp that is medically important

Dried rhizomes and roots

Part of Lily of the Valley that is medically important

Digitalis or Foxgloves

Most medically important source of cardiac glycosides