Chemical compound names in the "Reference"

Question

I am using EasyThesis template to write my thesis. I use bibtex to look after my entries in "References" section. There is one entry in the reference like :

@Article{sakya1994lyotropic,
  Title                    = {Lyotropic phase behaviour of n-octyl-1-O-$\beta$-{\footnotesize{D}}-glucopyranoside and its thio derivative n-octyl-1-S-$\beta$-{\footnotesize{D}}-glucopyranoside},
  Author                   = {Sakya, P. and Seddon, J. M. and Templer, R. H.},
  Journal                  = {Journal de Physique {II}},
  Year                     = {1994},
  Pages                    = {1311--1331},
  Volume                   = {4}
}

I expect the 'D' in the title should appear capital once finish compile, but I get 'd'.

I tried many ways to get the 'D' by removing the curly brackets {} but avail. Additionally, I need to use \footnotesize{D} because the D is smaller size.

Hope I get some help.