Timothy Ramadhar | Howard Profiles

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Faculty

Timothy R. Ramadhar

Assistant Professor

timothy.ramadhar@Howard.edu

Department/Office

Chemistry

School/College

College of Arts & Sciences

Education

Chemical Biology (Natural Products), Crystallography

Postdoctoral Fellowship
Harvard Medical School
2018

Chemistry (Organic)

Ph.D.
University of Toronto
2012

Honours Biochemistry

B.Sc.
University of Waterloo
2007

Expertise

Organic Chemistry (Synthetic and Computational)

Natural Products

Chemical Crystallography

Academics

Organic Chemistry Lecture I

Organic Chemistry Lecture II

Organic Chemistry Laboratory

Advanced Organic Chemistry

General Chemistry Laboratory I

General Chemistry Laboratory II

Research

Funding

National Science Foundation - Partnerships for Research and Education in Chemistry Planning Grant - Exploring a Partnership between Historically Black Universities in the District of Columbia and NSF's ChemMatCARS in Alignment with the NSF PREC Program (CHE-2334957, 2023-2025)

National Science Foundation - Major Research Instrumentation Grant - Acquisition of a High-Brilliance X-Ray Diffractometer for Fundamental Materials and Catalysis Research and Education at Howard University (DMR-2117502, 2021-2024)

Pfizer, Inc. (2019-2023)

Accomplishments

Selected Awards

NIH Ruth L. Kirschstein National Research Service Award (F32 Postdoctoral Fellowship Grant)

Grant Numbers: Year 1: 1F32GM108415-01A1 | Year 2: 5F32GM108415-02Granting Institute: National Institute of General Medical Sciences (NIGMS)

Natural Science and Research Engineering Council (NSERC) of Canada Alexander Graham Bell Canada Graduate Scholarship D3 (CGS D3)

NSERC Canada Graduate Scholarship M (CGS M)

Crystal structures, phase transition, and Hirshfeld surface analyses of the bromide and chloride congeners of aqua[2,4,6-tris(pyridin-4-yl)-1,3,5-triazine]zinc(II) halide

Dailey, M.; Jackson, E. W.; Ramadhar, T. R.* Acta Cryst. 2024, C80, 545–552.

The Crystalline Sponge Method: Quantum Chemical In Silico Derivation and Analysis of Guest Binding Energies

Cardenal, A. D.; Ramadhar, T. R.* CrystEngComm, 2021, 23, 7570–7575.

Application of Crystalline Matrices for the Structural Determination of Organic Molecules

Cardenal, A. D.; Ramadhar, T. R.* ACS Cent. Sci. 2021, 2021, 7, 406–414. Link

A conserved coccidian gene is involved in Toxoplasma sensitivity to the anti-apicomplexan compound, tartrolon E

Bowden, G. D.; Reis, P. M.; Rogers, M. B.; Bone Relat, R. M.; Brayton, K. A.; Wilson, S. K.; Di Genova, B. M.; Knoll, L. J.; Nepveux, F. J., V; Tai, A. K.; Ramadhar, T. R.; Clardy, J.; O'Connor, R. M.* Int. J. Parasitol. Drugs Drug Resist. 2020, 14, 1–7. Link

A Symbiotic Bacterium of Shipworms Produces a Compound with Broad Spectrum Anti-apicomplexan Activity

O'Connor, R. M.; Nepveux, F. J., V; Abenoja, J.; Bowden, G.; Reis, P.; Beaushaw, J.; Bone Relat, R. M.; Driskell, I.; Giminez, F.; Riggs, M. W.; Schaefer, D. A.; Schmidt, E. W.; Lin, Z.; Distel, D. L.; Clardy, J.; Ramadhar, T. R.; Allred, D. R.; Fritz, H. M.; Rathod, P.; Chery, L.; White, J. PLOS Pathogens 2020, 16, e1008600. Link

GABA-modulating bacteria of the human gut microbiota

Strandwitz, P.;‡ Kim, K. H.;‡ Terekhova, D.; Liu, J. K.; Sharma, A.; Levering, L.; McDonald, D.; Dietrich, D.; Ramadhar, T. R.; Lekbua, A.; Mroue, N.; Liston, C.; Stewart, E. J.; Dubin, M. J.; Zengler, K.; Knight, R.; Gilbert, J. A.; Clardy, J.; Lewis, K.* Nat. Microbiol. 2019, 4, 396. Link

Tundrenone: An Atypical Secondary Metabolite from Bacteria with Highly Restricted Primary Metabolism

Puri, A. W.;‡ Mevers, E.;‡ Ramadhar, T. R.;‡ Petras, D.; Liu, D.; Piel, J.; Dorrestein, P. C.; Greenberg, E. P.; Lidstrom, M. E.; Clardy, J.* J. Am. Chem. Soc. 2018, 140, 2002–2006. (‡ - Equal First Authorship) Link

Sequential O-Arylation/Lanthanide(III)-Catalyzed [3,3]-Sigmatropic Rearrangement of Bromo-Substituted Allylic Alcohols

Ramadhar, T. R.; Kawakami, J.; Batey, R. A.* Synlett 2017, 28, 2865–2870. (Contribution to a special issue dedicated to the 80th birthday of Prof. Victor A. Snieckus) Link

The Crystalline Sponge Method: A Solvent-Based Strategy to Facilitate Noncovalent Ordered Trapping of Solid and Liquid Organic Compounds

Ramadhar, T. R.;* Zheng, S.-L.; Chen, Y.-S.; Clardy, J.* CrystEngComm 2017, 19, 4528–4534. (Co-corresponding first author) Link

Macrotermycins A–D, Glycosylated Macrolactams from a Termite-Associated Amycolatopsis sp. M39

Beemelmanns, C.;‡* Ramadhar, T. R.;‡ Kim, K. H.;‡ Klassen, J. L.; Cao, S.; Wyche, T. P.; Hou, Y.; Poulsen, M.; Bugni, T. S.; Currie, C. R.; Clardy, J.* Org. Lett. 2017, 19, 1000–1003. (‡ - Equal First Authorship) Link

Homodimericin A: A Complex Hexacyclic Fungal Metabolite

Mevers, E.; Saurí, J.; Liu, Y.; Moser, A.; Ramadhar, T. R.; Varlan, M.; Williamson, R. T.; Martin, G. E.; Clardy, J.* J. Am. Chem. Soc. 2016, 138, 12324–12327. Link

Variable Genetic Architectures Produce Virtually Identical Molecules in Bacterial Symbionts of Fungus-Growing Ants

Sit, C. S.;‡ Ruzzini, A. C.;‡ Van Arnam, E. B.; Ramadhar, T. R.; Currie, C. R.; Clardy, J.* Proc. Natl. Acad. Sci. USA 2015, 112, 13150–13154. (Open Access) Link

Small Molecule Reactivation of Mutant p53 to wt-like p53 through the p53-Hsp40 Regulatory Axis

Hiraki, M.;‡ Hwang, S.-Y.;‡ Cao, S.;‡ Ramadhar, T. R.; Byun, S.; Yoon K. Y.; Lee, J. H.; Chu, K.; Gurkar, A. U.; Kolev, V.; Zhang, J.; Namba, T.; Murphy, M. E.; Newman, D. J.; Mandinova, A.; Clardy, J.;* Lee, S. W.* Chem. Biol. 2015, 22, 1206–1216. Link

Identification of a Dual Inhibitor of Janus Kinase 2 (JAK2) and p70 Ribosomal S6 Kinase1 (S6K1) Pathways

Byun, S.; Lim, S.; Mun, J. Y.; Kim, K. H.; Ramadhar, T. R.; Farrand, L.; Shin, S. H.; Thimmegowda, N. R.; Lee, H. J.; Frank, D. A.; Clardy, J.,* Lee, S. W.,* Lee, K. W.* J. Biol. Chem. 2015, 290, 23553–23562. Link

The Crystalline Sponge Method: MOF Terminal Ligand Effects

Ramadhar, T. R.; Zheng, S.-L.; Chen, Y.-S.; Clardy, J.* Chem. Commun. 2015, 51, 11252–11255. (Open Access) LinkFeatured in an RSC Chemistry World Magazine Article: "Confronting the Crystalline Sponge" (June 24, 2015)

Analysis of Rapidly Synthesized Guest-Filled Porous Complexes with Synchrotron Radiation: Practical Guidelines for the Crystalline Sponge Method

Ramadhar, T. R.; Zheng, S.-L.; Chen, Y.-S.; Clardy, J.* Acta Cryst. 2015, A71, 46–58. (Open Access) LinkInterviewed for an article in ACS Chemical and Engineering News (C&EN) Magazine: "Crystalline Sponges Catching on with Chemists" (Vol 93, Issue 7, pages 29-30, Feb. 16, 2015) Featured on the "In the Pipeline" blog in a post titled "Guidelines for MOF Crystallography" (December 12, 2014) and mentioned again in "X-ray Sponges Ride Again" (June 15, 2015)Gave commentary on Prof. Fujita's Chem. Sci. article (2015, 6, 3765-3768) in an RSC Chemistry World magazine story: "Crystalline sponge method strikes again" (May 26, 2015)Gave commentary on Prof. Fujita's J. Am. Chem. Soc. article (2016, 138, 32, 10140–10142) in an RSC Chemistry World magazine story: "Explosive intermediates muzzled by crystalline sponge" (August 24, 2016)

The Crystalline Sponge Method: Synthetic and Crystallographic Guidelines Published Conference Abstract

Ramadhar, T.; Zheng, S.-L.; Chen, Y.-S.; Clardy, J.* Acta Cryst. 2014, A70, C1784 (Published conference abstract for IUCr2014 in Montréal, Québec, Canada, August 5–12, 2014). Link

Natalamycin A, an Ansamycin from a Termite-Associated Streptomyces sp.

Kim, K. H.;‡ Ramadhar, T. R.;‡ Beemelmanns, C.;‡ Cao, S.; Poulsen, M.; Currie, C. R.; Clardy, J.* Chem. Sci. 2014, 5, 4333–4338. (‡ - Equal First Authorship) Link

Bacterial Symbionts in Agricultural Systems Provide a Strategic Source for Antibiotic Discovery

Ramadhar, T. R.; Beemelmanns, C.; Currie, C. R.; Clardy, J.* J. Antibiot. 2014, 67, 53–58 (Review article, contribution to a special issue dedicated to Prof. Christopher T. Walsh). Link

Mild Double Allylboration Reactions of Nitriles and Acid Anhydrides Using Potassium Allyltrifluoroborate

Ramadhar, T. R.; Bansagi, J.; Batey, R. A.* J. Org. Chem. 2013, 78, 1216–1221. Link

Recent Advances in Nucleophilic Addition Reactions of Organoboronic Acids and their Derivatives to Unsaturated C–N Functionalities

Ramadhar, T. R.; Batey, R. A.* in Boronic Acids: Preparation and Applications in Organic Synthesis, Medicine and Materials, Second Edition. Hall, D.G. Ed. Wiley-VCH: Weinheim, Germany. 2011, Chapter 9, pp. 427–477. (Book chapter) Link

Accurate Prediction of Experimental Free Energy of Activation Barriers for the Aliphatic-Claisen Rearrangement through DFT Calculations

Ramadhar, T. R.;* Batey, R. A.* Comp. Theor. Chem. 2011, 976, 167–182. (First co-corresponding author) Link

Resolving the Mechanistic Origins of E/Z-Selectivity Differences for the Aryl-Claisen Rearrangement through DFT Calculations

Ramadhar, T. R.; Batey, R. A.* Comp. Theor. Chem. 2011, 974, 76–78. Link

Allylation of Imines and their Derivatives with Organoboron Reagents: Stereocontrolled Synthesis of Homoallylic Amines

Ramadhar, T. R.; Batey, R. A.* Synthesis 2011, 1321–1346. (Review article) Link

Stereocontrolled Synthesis of Contiguous C(sp3)-C(aryl) Bonds by Lanthanide(III)-Catalyzed Domino Aryl-Claisen [3,3]-Sigmatropic Rearrangements

Ramadhar, T. R.; Kawakami, J.; Lough, A. J.; Batey, R. A.* Org. Lett. 2010, 12, 4446–4449. Link

Cyclobutanone Mimics of Penicillins: Effects of Substitution on Conformation and Hemiketal Stability

Johnson, J. W.; Evanoff, D. P.; Savard, M. E.; Lange, G.; Ramadhar, T. R.; Assoud, A.; Taylor, N. J.; Dmitrienko, G. I.* J. Org. Chem. 2008, 73, 6970–6982. Link

Inverse H-C ex situ HRMAS NMR Experiments for Solid-Phase Peptide Synthesis

Ramadhar, T. R.; Amador, F.; Ditty, M. J. T.; Power, W. P.* Magn. Reson. Chem. 2008, 46, 30–35. Link