I can't understand how can we get to and be so sure about so detailed information about the molecular structure of certain substances. How do we get this information? What tests are used to such?

Let's take for example somatostatin:

Molecular structure of somatostatin

you can see it is a big and extremely complex molecule, and my question is, how have we arrived to this structure? How can we know this to such detail? What tests do we use to know this?

  • $\begingroup$ Although this does not answer the general question, I should point out that your example is a polypeptide, so the atom connectivity could be determined mostly from its sequence (AGCKNFFWKTFTSC). That, plus the disulphide bond $\endgroup$
    – gilleain
    Mar 20, 2017 at 13:05
  • $\begingroup$ @gilleain that is one possibility for my example, in fact. But I'm still curious about a general answer $\endgroup$ Mar 20, 2017 at 13:25
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    $\begingroup$ I'd take a look at this wikipedia page on chemical structure. The take home point wont be whats on the page, but the techniques it references. Sometimes it's a combination of 3 or more different techniques that elucidate the final chemical structure, and all of them are somewhat difficult to understand at first. $\endgroup$
    – CKM
    Mar 20, 2017 at 14:56
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    $\begingroup$ Usually X-ray crystallography maybe, have a look at PDB for proteins. It (probably) has info on the original observations of discoverers. Also, many such structures are flexible and the accepted structure is chosen by consensus. $\endgroup$ Mar 21, 2017 at 6:04


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