Date	Severity	Status	Feedback
Sep 5 2016 7:53AM	Normal	Acknowledged	Hello, I have been looking at the structure for streptomycin on ChemSpider but am a little confused by the bonds shown joining the NH group in the upper part of the figure. In 2 places the bond is shown as two lines crossing each other, but I am unfamiliar with this usage. Could you explain to me what this means? Thanks in advance for your help. The crossed bonds indicate double bonds with unspecified double bond geometry.
Dec 9 2010 6:41PM	Normal	Rejected	Your structure for streptomycin appears not to be the correct tautomer - the double bonds in the guanidines are in the wrong position. You can see the correct structure in the WHO database of INNs, and in ISO 1750-1981 (Pesticides and other agrochemicals - Common names), and on my own website: http://www.alanwood.net/pesticides/streptomycin.html Alan Wood As structural representations of tautomeric species are 'freeze frame' representations of a delocalised system they are in one sense all wrong - but in reality one tautomeric representation is no more correct that another one (perhaps excepting cases where one is drawing mechanisms or performing computational calculations). However, I agree that all tautomers should be equally prominent in ChemSpider - I will link the different tautomeric representations using redirects
Feb 1 2009 9:59PM	Low	Fixed	3 structures for streptomycin Fixed