What is Gentamicin Sulfate?

Discussion in 'Chemistry' started by Eagle9, Apr 22, 2014.

  1. Eagle9 Registered Senior Member

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    Good day!

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    We bought Gentamicin Sulfate as antimicrobial agent against E.Coli in 2 ml capacity ampules. It has got inscription in russian language indicating its name, concentration (4 %) and etc.

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    I wanted to know the molecular weight and formula of this substance and in internet I found the controversial information.
    Here http://www.scbt.com/datasheet-203334.html it is written its formula C60H125N15O25S, and molecular weight: 1488.79. The exact name is also provided- Gentamicin Sulfate.
    But here http://www.chemblink.com/products/1405-41-0.htm other formula is provided C21H43N5O7.H2SO4 and molecular weight is equal to 575.67. The name is also provided there, however a bit different: Gentamycin sulfate. But the melting point for both substances are exactly the same: 218-237 °C.
    So, could you please tell me, what substance do I have in those ampules? I need their exact molecular weight and formula.

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  3. Eagle9 Registered Senior Member

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    I need to know the exact chemical composition of this:

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  5. origin Trump is the best argument against a democracy. Valued Senior Member

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  7. Trippy ALEA IACTA EST Staff Member

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    I think in an odd way they both may be right.

    Stop and consider:

    3(C[sub]20[/sub]H[sub]41[/sub]N[sub]5[/sub]O[sub]7[/sub]).H[sub]2[/sub]SO[sub]4[/sub] Has the same empirical formula as C[sub]60[/sub]H[sub]125[/sub]N[sub]15[/sub]O[sub]25[/sub]S
     
  8. Trippy ALEA IACTA EST Staff Member

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  9. origin Trump is the best argument against a democracy. Valued Senior Member

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    Yeah, it is weird. I do not understand what the sources are trying to say.:shrug:
     
  10. Trippy ALEA IACTA EST Staff Member

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    The joys of dealing with a biological product - This stuff is produced by the fermentation of some other 'thing' (too lazy to go look it up right now).
     
  11. Eagle9 Registered Senior Member

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    origin
    Trippy
    Actually, I have found many sources in internet about Gentamicin Sulfate but they contain controversial information. In that ampules there might be C1, C1a, C2 or their mixture. How this can be clarified? I mean, what is the simplest method/device for measuring its molecular weight?

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  12. origin Trump is the best argument against a democracy. Valued Senior Member

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    I do not now of an easy way to determine the molecular weight of a large organic molecule like that. You could use a mass spectrometer if you have one.

    If this is really that important to you ask the manufacturer. It probably is the case that manufacturers use different ratios of the different chemical species so your sample is probably unique, I do not know this for sure I am speculating.
     
  13. Trippy ALEA IACTA EST Staff Member

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    That's kinda part of the point that I was making in my previous post.

    The difference is in specific functional groups, so NMR spec might work as well.
     
  14. Captain Kremmen All aboard, me Hearties! Valued Senior Member

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    ....

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    Here's the diagrams from wiki. of Gentamicin, unsulphated.
    http://en.wikipedia.org/wiki/Gentamicin

    There are 20 Carbons in the basic molecule.
    Perhaps Trippy could explain why 3 Gentamicin molecules would bond with one sulphate ion.
    Two sounds reasonable, but why three?

    Which one would you use for molar weight?


    Nice to see someone asking a proper chemistry question.
     
  15. Trippy ALEA IACTA EST Staff Member

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    I haven't done any additional research into it, but at this stage? I'm as mystified as you are.
     
  16. Michael 歌舞伎 Valued Senior Member

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    Why? What are you using gentamicin for? If it's for TC then I'd suggest (a) you don't need it if you're aseptic (b) just add to the appropriate effective percentage, it doesn't have to be perfect.
     
  17. Captain Kremmen All aboard, me Hearties! Valued Senior Member

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    From what I read, it is an older antibiotic used topically for conjunctivitis.
     
  18. Michael 歌舞伎 Valued Senior Member

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    P/S kills bacteria and GM is used to kill yeast.
     
  19. Eagle9 Registered Senior Member

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    Michael
    If you are asking me I will answer-it is my master’s thesis. I am exploring how the various antibiotics affect the bacterial proliferation. And therefore I need the exact formula of Gentamicin Sulfate


    As I understand from these sites:
    http://www.scbt.com/datasheet-203334.html
    http://lib.njutcm.edu.cn/yaodian/ep/EP5.0/16_monographs/monographs_d-k/Gentamicin sulphate.pdf
    http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=0bc9fa00-1755-4989-a222-a038e970371f
    The formula of this substance should be considered as C60H125N15O25S and molecular weight as 1488.79; would it be right?

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