Any Chemists or chemestry students here that can answer?

Question

What is the difference between the kinds of sulpha found in things like Eggs and onions and the kinds of Sulpha based topicals used to treat skin conditions?

I mean like their structure and physical make up?

How does one effect and aggrevate skin conditions and the medications containing sulpha heal these same conditions?

Thanks Steve... That's exactly what i wanted to know!

Not dandruff exactly more like Metrogel for roseacea... but helpfull anyway!

Well darn it cain now who do I pick? Great answer as well because I obviously have made that exact mistake!

But I am not a chemist so... Thanks fo schooling me!

Answer 1

Well said, Steve. Ya stole m' thunder.

I wish to add, however, that the asker must be cautious not to confuse SULFUR with SULPHA. Sulpha (as in the sulpha drugs asked about originally), were antibacterials in use decades ago, that contained the SO2NH2, or sulfanilimide, functional group. These are fast fading because of the resistance to them that current strains of bacteria have.

Answer 2

Eggs contain the amino acids cystine and cysteine, which are organic sulfur compounds, building blocks of proteins. When eggs go bad, they emit H2S, which everyone knows has the smell of "rotten eggs." Onions also have organic sulfur compounds, allyl propyl disulfide, CH2=CHCH2-S-S-CH2CH2CH3, and the tear-jerker 1-propenylsulfenic acid, CH3CH=CH-SO2OH.

Sulfur compounds used to treat skin conditions like dandruff are selenium sulfide, SeS, Selsun Blue, and pyrithione, which is in Head&Shoulders. The structure of pyrithione is a hexagon of five carbon atoms and one nitrogen atom linked by alternating - and = bonds. The N is bonded to an O atom by a coordinate covalent bond, N->O. There is a mercapto group -SH attached to one carbon next to the nitrogen.