100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Summary IB Chemistry Option D: Medicinal Chemistry £6.87   Add to cart
Quickly navigate to
Preview
  2.  
  3. International Baccalaureate Diploma
  4.  
  5. Chemistry SL and HL

Summary

Summary IB Chemistry Option D: Medicinal Chemistry
 34 views  1 purchase
  • Module
  • Chemistry SL and HL
  • Institution
  • International Baccalaureate Diploma
  • Book
  • IB Chemistry Course Book

Detailed objective-by-objective summary notes for Option D: Medicinal Chemistry for IB Chemistry SL/HL. Contains information on everything you need to know according to each understanding, application or skill. Written by a IB HL Chemistry student who graduated with a 45/45.

Preview 3 out of 20  pages

  View example

Getting your document ready...

mobile-preview

Document information

  • Unknown
  • May 2, 2019
  • 20
  • 2016/2017
  • Summary

Subjects

  • chemistry
  • ib chemistry
  • option d
  • options
  • medicinal chemistry
  • ib
  • hl
  • sl

Connected book

book image

Book Title:

Author(s):

  • Edition:
  • ISBN:
  • Edition:

Written for

  • International Baccalaureate Diploma
  • Chemistry SL and HL
All documents for this subject (21)

Seller

avatar-seller
Stratiotes_Cirrhilabrus.rubriventralis

Reviews received

Content preview

Option D.1: Medicinal chemistry – Pharmaceutical products and drug actions
Medicines and drugs have a variety of different effects on the functioning of the body.

• Understanding: In animal studies, the therapeutic index is the lethal dose of a drug for 50% of the population (LD50) divided by
the minimum effective dose for 50% of the population (ED50).
(𝐿𝑒𝑡ℎ𝑎𝑙 𝑑𝑜𝑠𝑒 𝑜𝑓 𝑑𝑟𝑢𝑔 𝑓𝑜𝑟 50% 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛)
• Animal therapeutic index:
(𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑒𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑑𝑜𝑠𝑒 𝑜𝑓 𝑑𝑟𝑢𝑔 𝑓𝑜𝑟 50% 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛)
▪ Lethal dose: minimum dose of the drug that causes death in 50% of laboratory animals
▪ Minimum effective dose: minimum dose of the drug that produces the desired therapeutic effect in 50% of animals

• Understanding: In humans, the therapeutic index is the toxic dose of a drug for 50% of the population (TD50) divided by the
minimum effective dose for 50% of the population (ED50).
(𝑇𝑜𝑥𝑖𝑐 𝑑𝑜𝑠𝑒 𝑜𝑓 𝑑𝑟𝑢𝑔 𝑓𝑜𝑟 50% 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛)
• Human therapeutic index: (𝑚𝑖𝑛𝑖𝑚𝑢𝑚
𝑒𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑑𝑜𝑠𝑒 𝑜𝑓 𝑑𝑟𝑢𝑔 𝑓𝑜𝑟 50% 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛)
▪ Toxic dose: minimum dose of the drug that causes toxicity (unacceptably adverse effect) in 50% of the patients
▪ Minimum effective dose: minimum dose of the drug that produces the desired therapeutic effect in 50% of animals

• Understanding: The therapeutic window is the range of dosages between the minimum amounts of the drug that produce the
desired effect and a medically unacceptable adverse effect.
• Applications and skills: Discussion of experimental foundations for therapeutic index and therapeutic window through both
animal and human studies.

• Therapeutic window: range of dosage between minimum amounts of drug that
produce desired effect and a minimum amount of drugs that produces a
medically unacceptable adverse effect
▪ Opens: typically opens below ED50 (where some patients can still be
provided with minimal beneficial effect)
▪ Closes: typically closes below TD50 (where some patients might
experience significant adverse effect)

▪ Implication: like TI, drugs with narrow therapeutic windows must be
administered with great care an often require constant monitoring

• Understanding: Dosage, tolerance, addiction and side effects are considerations of drug administration.

• Dosage: the amount of drug administrated to the patient through various means and purposes

• Tolerance: where regular administration of certain drugs reduce the body’s response to specific medications
▪ Cause: accelerated drug metabolism or change in cellular function
▪ Effect: drug users need progressively higher doses of drug to obtain desired therapeutic effect
▪ Consequences: increase doses may lead to more pronounced side effect which may close the therapeutic window

• Addiction: compulsive desire of the user to take the drug regardless of the health problem it might cause
▪ Cause: psychological and physiological dependence on drugs
▪ Effect: may cause withdrawal symptoms causing patient to continue drug registration
▪ Consequences: addictive properties may outweigh their medical benefits; especially if the drug can build tolerance

▪ Even most addictive drugs can be used as painkillers in life-threatening situation or for patients with incurable
diseases – the high risk of side effects may not be as important than the therapeutic results

• Side effects: non beneficial effect on the human body arisen from administration of a certain drug
▪ Penicillin: underuse may lead to antibiotic resistance
▪ Aspirin: overuse can increase risk of gastrointestinal bleeding
▪ Opiates: overuse can be additive; may become substances of abuse
▪ Paracetamol: overuse can cause kidney, liver and brain damage

• Understanding: Bioavailability is the fraction of the administered dosage that reaches the target part of the human body.

• Bioavailability: fraction of the administered dosage that reaches the target part of the human body (or absorbed into bloodstream)
▪ Bioavailability in parenteral administration: 100%, or close to 100% by definition
▪ Bioavailability in oral/rectal administration: <100% due to decomposition and incomplete absorption

• Understanding: The main steps in the development of synthetic drugs include identifying the need and structure, synthesis, yield
and extraction.

• Identification of a lead compound (NCE)
▪ Lead compound (NCE): compounds that show any kind of promising activity towards specific biological target

▪ Drug discovery: compounds isolated from natural products or compounds synthesized and tested for therapeutic effect
▪ Drug design: complementary structure against target synthesized based on knowledge about drug receptor interaction
 Drug discovery is considerably more expensive and inefficient than drug design

, • Synthesis of compounds and preclinical trials
▪ Series of similar compounds to the lead compound is synthesized, characterized and subjected to experiments
▪ Properties: activity, toxicity, efficiency, stability, cost and other properties

• Yield and extraction
▪ High yield: potential drugs must be able to be synthesized with high yield
▪ Environmental effect: minimal environmental effect (minimal waste, easily extracted from source)

• Clinical trials
▪ Condition: drug is tested on humans through double blind experiment (patients are given drug or placebo)
▪ Only 1 in 10000 compounds synthesized is approved for medical used (phase IV)

▪ Phase I: small number of healthy volunteers (determine toxicity, safety dosage and side effects)
▪ Phase II: small number of patients (determine effectiveness and ED50, side effects)
Phase III: large number of patients (comparison with other drugs, further data on effectiveness)
▪ Phase IV: drug is released into public; post clinical trial (determine long term effects and chronic toxicity)

• Understanding: Drug–receptor interactions are based on the structure of the drug and the site of activity.

• Pharmaceutical drugs interact with binding sites of enzymes or receptors
▪ Binding to enzymes – reduce activity of enzymes by acting as biological inhibitors
▪ Binding to receptors – activates receptors so the cell responses to the chemical messages in its respective role

▪ Functional groups of the drugs and receptor should be complementary to one another for effective binding
▪ Efficient binding can be achieve by slight conformational changes (as noted in induced fit theory for enzymes)

• Drug receptor interactions
▪ Ionic groups (ammonium, -noate ions) – ionic bonding, coordinate bonding
▪ Polar groups (alcohol, carboxyl) – dipole-dipole interactions, hydrogen bonding
▪ Non-polar groups (alkyl, phenyl) – London dispersion forces

• Applications and skills: Discussion of drug administration methods.

• Oral registration: drugs delivered through mouth and absorbed through gastrointestinal tract
▪ Advantages: convenient, non-invasive, retrievable
▪ Disadvantages: low efficiency (disabled by stomach acid, reacts with food and beverage) low absorption

• Rectal registration: drug dissolved in suppository (dissolved in rectum)
▪ Advantages: avoid problems with stomach acid, can be used with nauseated patients
▪ Disadvantages: social stigma / distressing for some, cannot be taken in public, irretrievable

• Parenteral registration: drugs delivered by injections directly to the blood/target cells
▪ Advantages: fast delivery, ability to control precise amount of drugs
▪ Disadvantages: irretrievable, distasteful process for some patients

• Inhaled registration: drugs delivered as aerosol into the lungs
▪ Advantages: quick effect (hits brain and body simultaneously)
▪ Disadvantages: irretrievable, not possible with many drugs

• Applications and skills: Comparison of how functional groups, polarity and medicinal administration can affect bioavailability.

Polarity Functional groups Bioavailability
Polar Hydroxyl Soluble in water and are therefore quickly
Carboxyl absorbed from the gastrointestinal tract
Amino acids into bloodstream but cannot pass easily
through hydrophobic cell membrane
Non-polar Alkyl Insoluble in water and are therefore not
quickly absorbed from the gastrointestinal
tract into bloodstream but can pass easily
through hydrophobic cell membrane

• Nature of science: Risks and benefits—medicines and drugs go through a variety of tests to determine their effectiveness and safety
before they are made commercially available. Pharmaceutical products are classified for their use and abuse potential.

• International-mindedness: In some countries certain drugs are only available with prescription while in other countries these same drugs
are available over the counter.
• Guidance: For ethical and economic reasons, animal and human tests of drugs (for LD50/ED50 and TD50/ED50 respectively) should be
kept to a minimum.

, Option D.2: Medicinal chemistry – Aspirin and penicillin
Natural products with useful medicinal properties can be chemically altered to produce more potent or safer medicines.

• Understanding: Mild analgesics function by intercepting the pain stimulus at the source, often by interfering with the production
of substances that cause pain, swelling or fever.

▪ Mild analgesics: drugs that relief mild pain by intercepting the pain stimulus at the source
• Achieved through interfering of the production of prostaglandin that causes pain, swelling (inflammation) and fever

▪ Mechanism of aspirin in intercepting pain stimulus
• Binding to cyclooxygenase: drug binds to cyclooxygenase resulting in suppression of prostaglandin production
• Reduction of prostaglandins: prostaglandin is responsible for fever, swelling and transmission of pain impulses
• Inhibition of thromboxane production: prostaglandins are involved in production of thromboxane that stimulate the
aggregation of platelets and blood clotting

• Understanding: Aspirin is prepared from salicylic acid.
• Applications and skills: Explanation of the synthesis of aspirin from salicylic acid, including yield, purity by recrystallization and
characterization using IR and melting point.

▪ Process of aspirin synthesis from salicylic acid
• Mixing of chemicals: salicylic acid is mixed with
excess ethanoic anhydride
• Addition of catalyst: acid catalyst (concentrated
phosphoric acid) is added to the mixture
• Heating process: mixture is heated for a short time
• Dilution and crystallization: mixture is diluted with
water to produce crystals of aspirins
• Alternative route: aspirin can also be synthesised from ethanoyl chloride using a base catalyst

▪ Process of recrystallization for purity
• Recrystallization: rapid way of purifying a solid organic compound utilizing their thermodynamic properties

• Dissolving of solute: solid solute (i.e. impure crystal) is dissolved in the hot solvent (i.e. hot ethanol)
• Crystallization: solution is cooled slowly and solute crystallizes with less impurities for a more stable state
• Filtering and drying: crystals are then collected, washed and dried while impurities stay in solution

▪ Determining purity of aspirin
𝑒𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝑦𝑖𝑒𝑙𝑑
• Yield: (expected yield according to stoichiometric data)
𝑒𝑥𝑝𝑒𝑐𝑡𝑒𝑑 𝑦𝑖𝑒𝑙𝑑
▪ Low percentage yield: the likelihood of the crystals being more pure increases (however is not absolute)
▪ High percentage yield: percentage yield above 100% suggests presence of impurities

• Characterization using IR: products are dissolved in chloroform and peaks are compared with reference spectrum
▪ Resemblance to reference spectrum: the closer the resemblance, the purer the substance

• Melting point: temperature is scanned until the start and end melting temperature is determined
▪ Melting point of aspirin: aspirin melting point is expected at 136°C
▪ The closer the melting point to the expected value, the purer the substance

• Understanding: Aspirin can be used as an anticoagulant, in prevention of the recurrence of heart attacks and strokes and as a
prophylactic.

▪ Anticoagulant: drugs that prevent blood clot and/or prevents existing clots from getting larger
• Aspirin as an anticoagulant: aspirin inhibits the production of thromboxane that stimulates blood clotting
• Prophylactic property: drugs are used to reduce the risk/recurrence of heart attacks and strokes
• Side effects: anticlotting action of aspirin can lead to excessive bleeding of stomach especially in presence of alcohol

• Understanding: Penicillins are antibiotics produced by fungi.
• Understanding: Some antibiotics work by preventing cross-linking of the bacterial cell walls.

▪ Penicillins: groups of compound produced by fungus that have antibiotic properties
• Effect: penicillin deactivates the enzymes (transpeptidases) that forms cross-linking of bacterial cell walls
• Consequences: transpeptidases cause cell walls to become more permeable, resulting in osmotic pressure causing
water to enter the bacteria until they burst open and die

• Understanding: A beta-lactam ring is a part of the core structure of penicillins.
• Applications and skills: Explanation of the importance of the beta-lactam ring on the action of penicillin.

▪ Structure of the beta-lactam ring
• Beta-lactam ring: core structure of penicillin; ring consisting of bonds between 3 carbons and 1 nitrogen

• Expected bond angle: sp3/sp2 hybridization suggest the atoms should be arranged in a tetrahedral or trigonal planar
• Ring strain: nitrogen and carbon form a square planar arrangement with bond angle of 90°; less than expected
• Reactivity: the ring strain increases the reactivity and enables it to form covalent bonds with enzyme transpeptidases

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller Stratiotes_Cirrhilabrus.rubriventralis. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £6.87. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

13 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling
£6.87  1x  sold
  • (0)
  Add to cart