Nuclei are spinning at the new UP Diliman NMR Core Facility

Last Monday, the UP Diliman NMR (Nuclear Magnetic Resonance) Core Facility was inaugurated at the new research building of the Institute of Chemistry, National Science Complex, University of the Philippines, Diliman. Attending this historic event were UP, DOST and other government officials, UP faculty, researchers and students, and guests from other universities, research institutions, industry and media. The facility hosts 400 MHz and 500 MHz Varian NMR spectrometers. The NMRs were acquired by UP through the PharmaSeas Marine Drug Discovery Research Program funded by the DOST-PCAMRD (Philippine Council for Aquatic and Marine R&D), with the UP System committing counterpart funding for the preventive maintenance and operations of the NMR facility. The PharmaSeas program, based at the UP Diliman Marine Science Institute, aims to isolate and characterize anti-infective (antibacterial, antiviral) compounds from marine microorganisms associated with marine sponges, and anti-pain peptides from venomous marine snails. The study of marine organisms, which yield very small quantities of pure compounds for analysis, requires special features and capabilities of the NMRs. The 400 MHz machine is equipped with a 5-mm direct detection probe, while the 500 MHz machine has a 5-mm direct detection probe, a 3-mm triple resonance indirect detection probe and a nanoprobe. 

Aside from being used for research, the NMR facility is also a service laboratory that can routinely run 1D and 2D NMR experiments. The 400 MHz machine will also be used for hands-on training as part of regular spectroscopy courses in the Institute of Chemistry, as well as for short-term training courses, while the 500 MHz machine will be dedicated to research. Details about the submission of samples and requests for NMR class time are available at http://www.science.upd.edu.ph/. Nuclear magnetic resonance spectroscopy, commonly known as NMR spectroscopy, is a research technique that is used to determine the chemical structures of compounds by providing detailed information about the chemical environment of their component atoms. Certain nuclei (e.g. Hydrogen, 1H) can behave as tiny, spinning bar magnets that generate a magnetic field. When placed in an external magnetic field and irradiated with radiofrequency waves, these nuclei absorb energy of particular (resonant) frequencies. The specific pattern of radiofrequency absorption for different samples provides their signature NMR spectrum.A typical one-dimensional (1D) 1H or proton NMR spectrum may be interpreted by looking for the 1) number of signals (denotes how many kinds of protons), 2) position of the signals (identifies what kinds of protons), 3) intensities of the signals (quantifies the protons of each kind), and 4) multiplicity of the signals designates any neighboring protons). Similarly, Carbon-13 (13C) NMR spectra show the different chemical environments of the carbon atoms present in the molecule.  

Multi-dimensional NMR spectroscopy provides further information on through-bond or through-space couplings or connectivities. Two-dimensional NMR can be used to detect neighboring protons (COSY spectrum), to determine direct connectivity between two different nuclei (HSQC or HMQC spectrum), to assign connectivity between nuclei several bonds apart (HMBC spectrum), and to define the orientations and separations of these nuclei in space (NOESY spectrum).

The range of information obtained through NMR makes it among the most powerful instruments for elucidating chemical structures. Suitable samples range from small organic molecules to large polypeptides and proteins. Samples may either be in solution, gels, or solids. The diversity of applications for this technique allows its use for the many research projects conducted in our country.

NMR spectroscopy is the workhorse of scientists involved in the discovery of bioactive compounds from terrestrial plants, marine plants and animals, and microorganisms as a source of drug leads, and their subsequent synthesis. Of course, utmost care is observed to ensure that these researches will not have adverse effects on Philippine biodiversity and ecology. Ongoing drug discovery researches in the UP Diliman Institute of Chemistry include the isolation of bioactive constituents from plants with anti-diabetic, anti-inflammatory, anti-ulcer, anti-hypertensive, anti-infectious, anti-cancer and anti-malarial activities, as well as cholinesterase, lipooxygenase, and xanthine oxidase inhibitors.NMR spectroscopy allows the observation of both intramolecular and intermolecular interactions. This provides the opportunity to characterize different proteins through structure determination and investigations of their interactions with binding partners and target molecules. A current research project in the UP Diliman National Institute of Molecular Biology and Biotechnology focuses on investigating the interaction of recombinant integrin heterodimers and their ligands. This project aims to elucidate the relationship of these proteins and cancer metastasis, in hopes of identifying potential targets for drug therapy.NMR spectroscopy is also used in materials science. Ongoing researches include the synthesis of bioactive compounds and analogues, synthesis and development of diagnostic bioconjugates, synthesis of nanomaterials, nanocomposites, and hybrid nanocomposites, synthesis of drug immunoliposomes for drug delivery, synthesis of novel ionic liquids as green solvents and catalysts, and synthesis of ionic liquids for carbon capture technology development. NMR spectroscopy is also a complementary tool for the characterization of sedimentary organic matters (SOMs) in sediments or rock formations.Magnetic resonance is such a rich physical phenomenon that it has also found applications in medicine, specifically in the form of Magnetic Resonance Imaging (MRI). Based on the NMR characteristics of water (which makes up ~80 percent of the human body), the technique allows one to visually distinguish between the different chemical environments within the human body. To date, MRI is the safest medical radiologic technique for soft body tissue imaging, providing image resolution down to the millimeter range, and is extensively used to visualize physiological phenomena such as blood flow or disease states such as cancers. To this end, current research projects in the Institute of Chemistry also include the synthesis of radiologic pharmaceuticals which will further improve contrast enhancement in MRI.

The acquisition of the NMR spectrometers promises to hasten the rate of R&D work in the Philippines a hundred-fold! With this new development, we may limit the issues on IPR (intellectual property rights) and technology transfer that are associated with our previous need to outsource our data acquisition. By having our own facility, the National Science Complex provides the means for international collaboration on equal footing.

* * *

The members of the UPD NMR Guild are: Dr. Gisela P. Concepcion (Marine Science Institute), Dr. Irene M. Villaseñor (Institute of Chemistry), Dr. Florecita S. de Guzman (Institute of Chemistry), Dr. Neil Andrew D. Bascos (National Institute of Molecular Biology and Biotechnology), Dr. Aaron Joseph L. Villaraza (Institute of Chemistry), Dr. Portia Mahal G. Sabido (Institute of Chemistry), Dr. Christine C. Hernandez (Institute of Chemistry), Dr. Evangeline C. Amor (Institute of Chemistry), Dr. Armando S. Somintac (National Institute of Physics), Dr. Nemesio E. Montaño (Marine Science Institute), Ms. Arlene P. Bartolome (Institute of Chemistry), and Miguel Enrique Ma. A. Azcuna (Marine Science Institute). Contact us at [email protected].