Shu-yi Sophie Chen

Polytechnic University, Hong Kong

Title: The structure activity relationship of antidepressants and the specificity in drug therapy


Shu-yi Sophie Chen is the fi nal year student in the Department of Applied Biology and Chemistry Technology at the Hong Kong Polytechnic University in Hong Kong. She had been a visitor student in the Department of Life Sciences at the Peking University in Beijing, China in 2017. Shu-yi Sophie Chen had received the Talents Development scholarship by the Hong Kong S.A.R. government in 2017 and Reaching Out Award in 2016 for her medical volunteer placement in Sri Lanka by the Hong Kong S.A.R. government respectively. She had been exploring the medicinal chemistry in pharmacological therapy in antidepressants research as her fi nal year project under the guided by Dr Ga-Lai LAW at the Hong Kong Polytechnic University. Shu-yi Sophie Chen had also completed a medical placement and volunteer works in the Paediatric Surgery Units in the Karapitiya Teaching Hospital in Sri Lanka in 2016.


Antidepressants are prescribed commonly in depression therapy in the pharmaceutical methods; however, the long term administration time which is approximately 10 to 20 days and the unpleasant side eff ects are still accompanied during the medication therapy. Consequently, the full profi le of the medicinal chemistry of the antidepressants is discussed for an ideal structure in drug affi  nity. Antidepressants can be divided into diff erent types that depend on diff erent neurotransmitters as a target to serve as reuptake inhibitors. Furthermore, antidepressants can be categorized into (SSRIs) selective serotonin reuptake inhibitors and (SNRIs) selective norepinephrine selective reuptake inhibitors. Th e structure activity relationship of antidepressants is the goal in this project to explore the full profi le of specifi c structure in binding affi  nity and specifi city. A better view of the structure in antidepressants is benefi cial to establish a highly potent and precise antidepressant design. Halogens are found common in the antidepressants compound for the purpose of drug affi  nity. Especially, the fl uorine atom will serve as hydrogen bond acceptors that contribute to a high affi  nity in protein-ligand interaction, particularly in association with O-H or N-H group in the binding protein. Both the fl uoxetine and paroxetine contains fl uorine as the substituted group. However, the position matters when it comes to the affi  nity that the substituted group in fl uoxetine occupy only 4’-position while paroxetine occupies both 4’- and 3’-position on the aryloxy ring that proposes the spatial confi guration of the substitution group is signifi cant. Furthermore, the fl uoxetine contains trifl uoromethyl group on the phenolic rings in the Para-position exhibit 6-fold potency in SSRI activity compared to its parent non-fl uorinated structure.  In summary, a more clear direction in the development of antidepressants can be suggested to be related to both the types and positions of substituents on the aromatic rings.  Mostly, these antidepressants are not only treated to depression disorder but also can be used in other health condition such as NRIs in chronic pains and ADHD. Hence, an outcome of improved effi  cacy in terms of its specifi city and potency of antidepressants can benefi t people to overcome the healthy condition and provide a more profi le in the drug design