10. Aromatic hydrocarbons, glycols and aldehydes

Question 1

Aromatic Hydrocarbons: Benzene?

Answer 1

Benzene: used for its solvent properties and as an intermediate in the synthesis of other chemicals important component of gasoline. acute toxic effect: depression of the CNS, Vertigo, drowsiness, headache Chronic exposure: bone marrow injury (Aplastic anemia, leukopenia, pancytopenia, leukemia) Toluene (methylbenzene): does not possess the myelotoxic properties of benzene CNS depressant and a skin and eye irritant Xylene (dimethylbenzene) Comparable to toluene Fenols

Question 2

Aromatic nitro- and amino compounds

Answer 2

relatively rare in nature and have been introduced into the environment mainly by human activities widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. The nitro group - electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines.

Question 3

Aromatic nitro- and amino compounds: (aminobenzene, aminophen, arylamine, benzenamine):

Answer 3

fishy odor Inhalation, Ingestion Acute Exposure: Many of the adverse health effects of aniline are due in part to the formation of methemoglobinemia

Question 4

Aniline

Answer 4

CNS: Begins with euphoria, confusion, ringing in the ears, weakness, disorientation, dizziness, impaired gait, lethargy drowsiness, convulsions, loss of consciousness, and coma - probably secondary to lack of oxygen Chronic exposure: neurasthenia, hypochrom anaemia, cyanosis. Urinary bladder carcinoma treatment: Symptomatic individuals should be administered supplemental oxygen methemoglobin antidote, methylene blue, as soon as possible standard - iv 1 to 2 mg of methylene blue /kg body weight activated charcoal - 1 g/kg

Question 5

Nytrobenzene

Answer 5

• Approximately 97% of nitrobenzene is consumed in the production of aniline, which is a precursor to rubber chemicals, pesticides, dyes, explosives, and pharmaceuticals
• Acute intoxication symptoms: irritation of mucosa , CNS depression, methemoglobinaemia
• Chronic: anaemia, haemolytic icterus, CNS

Question 6

2,4-dinitrophenol (DNP) , 4,6-Dinitrocresol

(DNOC)

Answer 6

• Used as pesticide
• Used as Weight Loss Agent!!!

MOA:

• uncoupling of oxidative phosphorylation - stopping the final energy conversion by exporting the proton ions (H+) needed for ATP
• Adenosine triphosphate (ATP) - final product of the tricarboxylic acid (Krebs) cycle in mitocondria along with CO2 and H2O.
• ATP synthetase converts ADP to ATP with the addition of an inorganic phosphate molecule.
• This shift in the proton electrochemical gradient then results in potential energy dissipating as heat, instead of being converted to ATP, with rapid consumption of calories
• The heat production represents a failure in thermoregulatory homeostasis, leading to uncontrolled hyperthermia
• Symptoms:

–acute hyperpyrexia, dehydration, blood pressure ¯ heart frequency ­, dyspnoe, cyanosis, anoxia, lung edema

–Chronic: loss of weight, fever, impairment of kidney-, liver-, heart-, bone marrow function, hemolytic anaemia

•Therapy (acute)

–cold bath, O2 inhalation, 0,9 % NaCl, glucose infusion