Intro to pharmacognosy

• What is the discipline that studies drugs from natural sources?

  Pharmacognosy
• What is the role of Pharmacognosy in drug discovery?

  It studies natural products for drug development
• What are the two types of metabolites defined in pharmacognosy?

  Primary and secondary metabolites
• How many medicinal plants are listed globally by the WHO?

  20,000 medicinal plants
• What percentage of people worldwide rely on plant-based medicines?

  75-80%
• What fraction of 'Western' drugs are derived from natural products?

  Up to half
• What percentage of anti-cancer drugs are derived from natural products?

  60%
• What is the main focus of modern drug development?

  Biologically active natural products
• Why is correct identification crucial in botany?

  Incorrect identification can have serious consequences
• What is ethnopharmacology?

  The study of materials used by ethnic groups
• What is the purpose of bioassay-guided fractionation in phytochemistry?

  To identify biological activity in extracts
• What are the pharmaceutical roles of plants today?

  Used as crude drugs, isolated chemicals, semi-synthetics
• What is the active component in Willow Bark used for pain relief?

  Salicin
• What are the differences between conventional medicines and crude drugs?

  • Conventional medicines:
  • One active species
  • Defined dose
  • Clear quality specification
  • Crude drugs:
  • Many active species
  • Undefined doses
  • Variable quality specification
• What is the chemical formula for Salicin?

  $C_{13}H_{18}O_{7}$
• What is the significance of Salicin in drug development?

  It was a lead compound for Aspirin
• What is the main component of Aspirin?

  Acetylsalicylic acid
• What is the impact of Aspirin derived from Willow Bark?

  It led to the development of synthetic drugs
• What are primary metabolites produced by green plants?

  Carbohydrates, proteins, lipids, nucleic acids
• What are secondary metabolites formed through?

  Specific enzymatic reactions
• What is the function of secondary metabolites in plants?

  Protection from herbivory and predation
• What are the major classes of secondary metabolites?

  • Alkaloids
  • Phenylpropanoids
  • Phenolics
  • Terpenes and steroids
  • Polyketides and fatty acids
  • Specialized amino acids, peptides, carbohydrates
• What are glycosides?

  Molecules composed of sugar and non-sugar components
• What are the types of glycosidic links?

  O-glycoside, N-glycoside, S-glycoside, C-glycoside
• How are glycosides formed?

  By interaction of nucleotide glycosides with an OH group
• What sugars can be part of glycosides?

  Monosaccharides and disaccharides
• What is the non-sugar portion of glycosides called?

  Aglycones or genins
• How can biosynthetic routes be elucidated?

  By feeding radiolabelled precursors to plants