l-histidine

natural amino acid that is converted to histamine

diphenhydramine

ethanolamine H1 first generation antihistamine

clemastine

ethanolamine H1 first generation antihistamine

extra C part of ring system

Cl- more antihistamine than anticholinergic activity

pyrilamine

ethylenediamine first generation H1 antihistamine

meclizine

piperazine derivative

cyclic ethylenediamine

hydroxyzine

piperazine derivative

chlorpheniramine

chiral center and Cl

tripolidine

alkene amine

E configuration

promethazine

phenothiazine ring system with ethylenediamine

olopatadine

dibenzoxepine ring system, carboxylic acid

terfenadine

first non-sedating antihistamin

caused arrythmia

fexofenadine

added carboxylic acid- polar groups and zwitterion formation

no arrythmias or anticholinergic action

loratadine

doesnt cross BBB- polar groups, h bond capability and efflux pump substrate

desloratadine

more potent than loratadine with carbamate hydrolyzed

polarizable groups, H bond capability and efflux pump substrate

cetirizine

formed from hydroxyzine

carboxylic acid instead of alcohol on terminal C

forms zwitterion

khellin

natural product

bronchodilating activity

chromome ring system

cromoyln sodium

 bichromome ring system

cimetidine

- imidazole ring

ranitidine

- furan bound to tertiary amine

famotidine

- thiazole bound to guanidine

nizatidine

- thiazole ring bound to guanidine

omeprazole

- 2 methoxy groups- 1 on each ring

- can form esomeprazole from s-enantiomer

lansoprazole

- OCH2CF3 on pyridine ring

- no subst. on benzimidazole ring

- dexlansoprazole from r-enantiomer

rabeprazole

- O(CH2)3OCH3 on pyridine

- no subst on benzimidazole

pantoprazole

- OCH3 on pyridine ring

- OCHF2 on benzimidazole ring- F directly bound making it e- withdrawing so N has lower pKa than others

l-tryptophan

biosynthesis of serotonin step 1

l-5hydroxytryptophan

 add OH to indole ring via tryptophan hydroxylase

serotonin

formed from l-aromatic amino acid decarboxylase, lose CO2H by amine on side chain

5-HIAA (5-hydroxyindole acetic acid)

- formed from serortonin metabolized by MAO and aldehyde dehydrogenase

5-hydroxytryptophol

- formed from serotonin metabolized by MAO then aldehyde reductase

melatonin

- formed from acetylated serotonin via 5-hydroxyindole-omethyltransferase

- add methyl on OH on indole ring

sumatriptan

- 5ht 1B/1D receptor agonist

- polar group, indole, methylamine side chain

lasmiditan

- selective 5HT 1F agonist (NAAMA)

- blocks pain transmission from trigeminal nerve

lorcaserin

- selective 5HT 2C receptor agonist

- for obesity

dolasetron

- metabolized quickly to hydrodolasetron as active metabolite

- has indazole, carbonyl and basic amine so 5HT3 antagonist

- changes carbonyl to OH on amine ring system

granisetron

- has indazole, carbonyl and basic N so 5HT3 antagonist

- basic N part of granatane ring system

ondansetron

- indazole, carbonyl, and basic N part of imidazole

- serotonin 5HT3 antagonist

palonosetron

- more complicated ring system- binds to lipophilic pocket to increase affinity for receptor

- N part of quinachidine ring system