In accordance with the structural characteristics of thiazolidinedione drugs and highly bioactive tyrosine derivatives, we tentatively designed the l-phenylglycine derivatives TM1 and TM2 based on basic principles of drug design and then synthesized them. The in vitro screening of peroxisome proliferator-activated receptor gamma (PPARγ) activated activity, α-glucosidase inhibitory and dipeptidyl peptidase-4 inhibitory activities showed that the novel molecule M5 had efficient PPAR response element (PPRE) activated activity (PPRE relative activity 105.04% at 10 μg·mL-1 compared with the positive control pioglitazone, with 100% activity). Therefore, M5 was selected as the hit compound from which the TM3 and TM4 series of compounds were further designed and synthesized. Based on the PPRE relative activities of TM3 and TM4, we discovered another new molecule, TM4h, which had the strongest PPRE relative activity (120.42% at 10 μg·mL-1). In addition, the concentration-dependent activity of the highly active compounds was determined by assaying their half-maximal effective concentration (EC50) values. The molecular physical parameter calculation and the molecular toxicity prediction were used to theoretically evaluate the lead-likeness and safety of the active compounds. In conclusion, we identified a potential PPARγ lead molecule and developed a tangible strategy for antidiabetic drug development.