Group 13: Medicinal Inorganic Chemistry 5

Question 1

What are the elements within Group 13?

Answer 1

1. Boron (B)
2. Aluminum (Al)
3. Gallium (ga)
4. Indium (In)
5. Thallium (TI)

Question 2

Describe the chemistry of Boron group? (electron shells, oxidation number, reaction)

Answer 2

Three electron in outer energy levels (valence layers)

Boron and aluminium occur with oxidation number +3 in their compounds- few exceptions are called ionic

Boron is considered a metalloid

Substance can react as an acid and base (amphoteric)

Base (neutralizing an acid): Al(OH)3 + 3HCl → AlCl3 + 3H2O
Acid (neutralizing a base): Al(OH)3 + NaOH → NaAl(OH)4

Question 3

What is boron (boric acid) used for medicinally?

Answer 3

Antiseptic

Examples: 
Eye wash (very diluted) 
Acne treatment
Athlete's foot prevent
Bacterial vaginosis (high pH)
Topic astringent

Question 4

What is boron neutron capture therapy

Answer 4

Enriched 10B compounds selectively taken up by cancer tissues

Patients treated with beam of low energy neutrons (low neutron radiation dose)

Nuclear reaction between enriched 10B and neutron produces heavy ion radiation- bombards tumour cells from inside

Question 5

What is Aluminium is used for manly for purifying and how does this work?

Answer 5

Water purification

Al3+: settling or sedimentation of suspended matter in water is accelerated by adding lime (CaO) & Al2(SO4)3

Forms Gelatinous Precipitate of Al(OH)3 which carries with it suspended solids, colloidal material and most bacteria

Question 6

What are the equations for CaO and Al2(SO4)3 when producing a precipitate which is used in water purification?

Answer 6

Lime = slightly basic - precipitates added
CaO(s) + H2O(l) → Ca2+(aq) + 2OH-(aq)
Al3+(aq) + 3OH-(aq) → Al(OH)3(s)

Question 7

Describe aluminium in terms of diet?

Answer 7

1. Natural barriers limit the absorption of Al3+ in diet and are bypassed via intravenous administration
2. Al3+ in diet is around 2.5mg per day
3. Accumulation may occur if there are renal impairment issues but this is not normally a case

Question 8

Describe the use of aluminium as a phosphate binder?

Answer 8

1. Used in patients with end stage renal failure and Hyperphosphatemia
2. Al(OH)3 enters acidic stomach- Al3+ ions form
3. Small amount absorbed in stomach but majority is in the gut
4. Al3+ is freshly precipitated as colloidal amorphous Al(OH3) (large surface area adsorbs phosphate ions)
5. Dialysis dementia

Question 9

Define what an adjuvant is and its role?

Answer 9

1. Adjuvant- agent or a mixture of agents which possess the ability to bind to specific antigen
2. Increase anti-body response to vaccination

Question 10

Give examples of adjuvants?

Answer 10

1. Aluminium Al(OH)3, Al2O3 and other metal oxides (ZrO2, SiO2, Fe2O3)
2. Al3+ salts are licensed to be used in adjuvant anthrax vaccinations and improve the effectiveness of them

Question 11

Describe in detail how the aluminium adjuvant works?

Answer 11

1. Absorbs many antigenic molecules over wide surface area
2. Enhance the interaction of immune cells with presenting antigens and stimulating immune response (AlOH3) or AlPO4 used in Haemophilus influenza type B vaccinations

Question 12

Describe aluminium role as anti-perspirant?

Answer 12

Acts as a plug of Al(OH)3 within sweat duct

Question 13

Describe aluminium’s use as an antacids?

Answer 13

1. Major use of Al3+ based medication
2. Neutralise excess stomach acid
3. Cytoprotective effects towards attacks gastric mucosa
4. Heals gastric and duodenal ulcerations

Question 14

Describe the toxicity content of aluminium?

Answer 14

1. Accumulates in sensitive loci (amnesia, Alzheimer’s diseases- aluminium is present in brain of patients)
2. Embryonic and fetal toxic effects in humans and animals

Question 15

Describe the potential new role of gallium?

Answer 15

New chemotherapeutic agent thats under development

Question 16

Describe the role of Thallium?

Answer 16

1. Radio diagnostic agent

2. Radiotherapy