CHAPTER 7

• ALKALOIDS - are extremely difficult to define for they do not represent a homogenous group of compounds either from the chemical, biochemical or physiologic point of view.
• Alkaloids - Naturally occurring chemical compounds

  containing basic nitrogen atoms.
• Alkaloids - Commonly applied to basic nitrogenous

  compounds of plant origin that is

  physiologically active.
• Alkaloids - Usually classified according to the nature of the basic chemical structures from which they are derived.
• Alkaloids - All do occur in plants which have been the rich sources.
• Alkaloids - Some are found in animals and practically all have been reproduced by chemical synthesis.
• alkaloids in animals:

  Bacteria, Fungi, Frogs, Insects
• Alkaloids - Usually a bitter taste.
• Alkaloids - By agreement, chemical rules designate

  that the name of alkaloids should end in

  INE.
• Alkali-like - a.k.a. alkaloid, commonly used to designate basic heterocyclic nitrogenous compounds of plant origin that are physiologically active.
• Some alkaloids are not basic:

  • Colchicine
  • Piperine
  • Quaternary alkaloids
• The nitrogen in some alkaloids is not a heterocyclic ring:

  • Cochicine
  • Ephedrine
  • Mescaline
• TYPES OF ALKALOIDS:

  • True/Typical Alkaloids
  • Proto-Alkaloids
  • Pseudo-Alkaloids
  • False Alkaloids
• False Alkaloids - Non-alkaloids that gives false positive reaction with alkaloidal reagents.
• Pseudo-Alkaloids- Not derived from amino acids but have nitrogen in a heterocyclic ring. – Caffeine
• Proto-Alkaloids - Derived from amino acids and do not have nitrogen in a heterocyclic ring. – Ephedrine
• True/Typical Alkaloids - Derived from amino acids and have nitrogen in a heterocyclic ring. – Atropine
• Alkaloids - Are cyclic organic compounds

  containing nitrogen in negative state of oxidation with limited distribution among living organisms.
• Alkaloids (occurence) -Rare in lower plants.
• Alkaloids (occurence) -Dicots are more rich in alkaloids than monocots.
• Alkaloids (occurence) - Monocot plants with Alkaloids:

  • Amaryllidaceae
  • Amaryllidaceae
• Families free from Alkaloids:

  • Rosaceae
  • Labiatae
• Families rich in Alkaloids:

  • Apocynaceae
  • Solanaceae
  • Papaveraceae
  • Rubiaceae
  • Ranunculaceae
  • Berberidaceae
• Alkaloids - function as Poisonous agent protecting the plant against insects and hervibores due to its bitterness

  and toxicity
• Alkaloids - (function) End product of detoxification reaction representing a metabolic locking-up of

  compounds otherwise harmful to the plants–

  waste products.
• Alkaloids - function As regulatory growth factor in certain metabolic systems.
• Alkaloids - Reserved the substance capable of supplying nitrogen or other necessary elements to the plant’s economy– Sources of nitrogen in case

  of nitrogen deficiency.
• Alkaloids - (function) Utilized as source of energy in case of deficiency in carbon dioxide assimilation.
• Plant parts:

  • All parts – Datura
  • Leaves– Tobacco
  • Barks – Cinchona
  • Roots – Belladonna, Aconite
  • Fruits – Black pepper
  • Seeds – Areca, Nux vomica, Physostigma
  • Rhizomes and Roots – Ipecac, Hydrastis
  • Latex – Opium
  • Fungi – Ergot
• Ways in obtaining names of alkaloids:

  • Generic name of the plant
  • specific name of the plant
  • common name of the plant
  • their physiologic activity
  • discoverer
  • prefix or suffix
• From the Generic Name of the plant yielding them.

  • Atropine – Atropa
  • Hydrastine – Hydrastis
• From the Specific Name of the plant yielding them.

  • Cocaine – Coca
  • Belladonine - Belladonna
• From the Common Name of the plant yielding them.

  • Ergotamine – Ergot
• From their Physiologic Activity

  • emetine
  • morphine
• Occasionally, from the Discoverer

  Pelletierine– Pelletier
• Sometimes, a prefix or suffix is added to

  the name of a principal alkaloid to

  designate another alkaloid from the

  same source.

  • Quinine
  • Quinidine
  • Hydroquinidine
• Forms:

  • Free bases
  • Salts with Organic acids
  • Salts with Inorganic acids
  • Salts with Special acids
  • Glycosidal form
• Salts with Organic acids

  • Oxalic acid
  • Acetic acid
• Salts with Inorganic acids

  • Hydrochloric acid
  • Sulfuric acid
• Salts with Special acids:

  • Meconic acid – Opium
  • Quinic acid – Cinchona