“…Functional groups which have been reported involved in the biosynthesis of NPs are alcohols, aldehydes, amines, carboxyls, ketones, hydroxyls, sulfhydryls (Baker et al, 2013;Rai and Yadav, 2013;Huang et al, 2015), so it can be assumed that virtually any biological compound to provide such groups is usable to convert metal ions in NPs. However, Rai and Yadav (2013) indicated that some compounds like terpenoids, flavonoids, various heterocyclic, polyphenols, reducing sugars, glutathione and ascorbate are directly involved in biosynthesis, while others such as proteins function as stabilizing agents, forming by adsorbing an organic cover called crown.…”