Where does the suffix -tine come from? For e.g., Ovaltine, Creatine, etc. all have a -tine suffix. What is the meaning connoted to the noun attached?
It's not -tine, but rather -ine, from the Latin -inus, in turn from the Greek -inos, meaning "of", "pertaining to", "made from" or "similar to".
Ovaltine < Ovomaltine < Ovo (Latin: egg) + malt + -ine.
Creatine < kreat- (Greek: stem of kreas) + -ine.
While Ovaltine is a brand (with an interesting history) of health drink, the supplement Creatine, technically isn't in itself a brand. It's the name of an amino acid which can help build muscle-mass. Furthermore, proteins are made up of combinations of amino acids. All these -tines and -ines lend an air of scientific reliability to brand names which like to tack them on at the end. That said, a number of these products do tend to be health-oriented and often actually are full of protein.
Etymonline provides the following explanation for the -ine suffix often seen in Chemistry: