Teaching Areas and Courses:
Medicinal Chemistry I (PHA 340)
Medicinal Chemistry II (PHA 341)
Advanced Medicinal Chemistry (PHA 720)
Topic in Medicinal Chemistry (PHA 725)

Research Interests:
My current research is focused on developing novel approaches to increase cancer sensitivity to chemotherapy and radiotherapy.  The project involves rational design and synthesis of bioactive compounds followed by in vitro and in vivo evaluation of the synthesized compounds.  The laboratory techniques involved are structure characterization by NMR, IR, UV, and MS; in vitro evaluation of compounds of biological interest by employing enzyme assays and cell culture experiments; in vivo evaluation with mice, rats and other animal species; and biological sample analysis with HPLC, UV, and LC/MS.

Recent Publications:

1.   Seefeldt, T., Zhao, Y., Chen, W., Raza, A., Carlson, L., Herman, J., Stoebner, A., Hanson, S., Foll, R., Guan, X. Characterization of a novel dithiocarbamate glutathione reductase inhibitor and its use as a tool to modulate intracellular glutathione. Submitted to J. Biol. Chem. 2008, (Submitted)

2.   Zhao, Y., Seefeldt, T., Chen, W., Wang, X., Matthees, D., Hu, Y., Guan, X. Effects of glutathione reductase inhibition on cellular thiol redox and related systems. J. Biol. Chem. 2008, (submitted).

3.   Chen, W., Zhao, Y., Seefeldt, T., Guan, X. Determination of thiols and disulfides via HPLC quantification of 5-thio-2-nitrobenzoic acid. J. Pharm. Biomed. Anal.2008, (Submitted)

4.   Pisal, D.S., Yellepeddi, V.K., Kumar, A., Kaushik, R.S., Hildreth, M.B., Guan, X., Palakurthi, S. Permeability of surface-modified polyamidoamine (PAMAM) dendrimers across Caco-2 cell monolayers. Int J Pharm. 2008, 350, 113-121.

5.   Dwivedi, C.; Valluri, H.B.; Guan, X.; Agarwal, R. Chemopreventive effects of ?-santalol on ultraviolet B radiation-induced skin tumor development in SKH-hairless mice. Carcinogenesis. 2006, 27, 1917-1922.

6.   Seefeldt, T.; Dwivedi, C.; Peitz, G.; Carlson, L.; Herman, J.; Zhang, Z.; Guan, X. 2-Acetylamino-3-[4-(2-acetylamino-2-carboxy-ethylsulfanylcarbonylamino)phenylcarbamoyl-sulfanyl]propionic acid and its derivatives as a novel class of glutathione reductase inhibitors. J. Med. Chem. 2005, 48, 5224 - 5231.

7.   Dwivedi, C.; Maydew, E.R.; Hora, J.J.; Ramaeker, D.M.; Guan, X. Chemopreventive effects of various concentrations of alpha-santalol on skin cancer development in CD-1 mice.  Eur. J. Cancer Prev. 2005 14, 473-476.

8.   Kaur, M.; Agarwal, C.; Singh, R. P.; Dwivedi, C.; Guan, X.; Agarwal, R. Skin cancer chemopreventive agent, alpha-Santalol , induces apoptotic death of human epidermoid carcinoma A431 cells via caspases activation together with dissipation of mitochondrial membrane potential and cytochorme c release. Carcinogenesis 2005, 26, 369-380.

Book Chapters:

1.         Guan, X. Metabolic Activation and Drug Targeting. In Drug Deliveray Principles and Applications.   Wang, B., Siahaan, T., Soltero, R., Eds.; John Wiley and Sons: New York, 2005; pp 201-244.

2.       Guan, X. The role of drug metabolism in drug discovery. In Evaluation of Drug Candidates for Preclinical Development: Pharmacokinetics, Metabolism, Pharmaceutics, and Toxicology. Davis, C., Wang, B., Han, C., Eds; John Wiley and Sons: New York. (Submitted)

Research Grants:

1.       Study of antitumor mechanism of diarylsulfonylureas, PI, 1999-2003, National Institutes of Health.

2.       Glutathione reductase and tumor sensitivity to radiation, PI, 2003-2006, National Institutes of Health.

3.       Inhibition of Glutathione Reductase as a Novel Approach to Reverse Ovarian Cancer Resistance to Chemotherapy, PI, 2005 Governor Rounds’ Individual Research Seed Grant Awards.

4.       Inhibition of glutathione reductase and ovarian cancer drug resistance reversal, PI, 2006-2009, National Institutes of Health.

Active Research Projects:

1.       Design and synthesis of novel glutathione reductase inhibitors.

2.       Investigation of glutathione reductase inhibitors as agents to increase cancer sensitivity to chemotherapy.

3.       Investigation of glutathione reductase inhibitors as agents to increase cancer sensitivity to radiotherapy.

Professional Memberships:

1.       American Chemical Society, Division of Medicinal Chemistry

2.       American Association of Colleges of Pharmacy

3.       Rho Chi Honorary Society

4.       Sigma Xi Scientific Honor Society

5.       Chinese-American Chemistry & Chemical Biology Professors Association (CAPA)

Awards/Honors:

1.       Arthur W. Davidson Award for outstanding achievement as a graduate student in one of the chemically-based disciplines, received from the University of Kansas Chapter of Phi Lambda Upsilon (National Honorary Chemical Society).

2.       The 6th Annual Graduate Honor Award from the School of Pharmacy, University of Kansas.

3.       1991 Irsay-Dahle Award as an outstanding graduate student in the Department of Medicinal Chemistry, University of Kansas.

4.       College of Pharmacy Faculty Recognition Award for Research and Scholarship for 1997-1998 from the College of Pharmacy, South Dakota State University.

5.       College of Pharmacy Faculty Recognition Award for Research and Scholarship for 2000-2001 from the College of Pharmacy, South Dakota State University.