Research Accomplishments

A. Early Research and Translational Activities, 1976-1982. Dr. Serianni did his graduate studies in the Department of Biochemistry at Michigan State University, working under the guidance of Dr. Robert Barker. During this early part of his career, Dr. Serianni worked on the synthesis of stable isotopically labeled saccharides, mainly 13C, to be used in conjunction with NMR to probe their structures, dynamics and reactivities (chemical and enzymic) in solution. At this time (1976-1980), applications of labeled saccharides were largely undeveloped, in part because access to labeled saccharides was very limited. Dr. Serianni’s work addressed this need in three ways: (1) he developed a new and general chemical method to incorporate 13C and other stable isotopes into aldoses site-specifically by the process of cyanohydrin reduction (to be distinguished from the well-known but less efficient Kiliani-Fischer synthesis); (2) he demonstrated the use of enzymes as reagents to transform labeled aldoses prepared by cyanohydrin reduction into other valuable labeled carbohydrates such as ketoses (via aldose-ketose isomerases) and oligosaccharides (via sugar nucleotides and glycosyltransferases); and (3) he discovered a novel mechanism of saccharide backbone rearrangement (C1-C2 transposition), catalyzed by molybdate ion, that revolutionized the synthesis of labeled saccharides.

These key developments, especially (1) and (3), represented disruptive technologies that changed the field of saccharide isotopic labeling tremendously, and made possible new structure/function studies in chemistry, biochemistry and biomedicine. Testimony to their disruptive character is demonstrated by the fact that, in 1982, Dr. Serianni cofounded a company in the state of New York, Omicron Biochemicals Inc. (since then incorporated in the state of Indiana). This company addressed the rapidly expanding needs of researchers for labeled saccharides in chemical, biochemical, biomedical and clinical research. It is noteworthy that this translational activity occurred at a time when entrepreneurial activities were rare and often discouraged in academics (which contrasts markedly with present day sentiments). More than thirty years later, Omicron Biochemicals Inc. remains in operation, recently occupying (in 2006) a newly constructed 8000 sq. ft. research facility, and employing >10 BS-PhD-level scientists. The company’s web site lists > 600 labeled (and unlabeled) sugars prepared routinely on-site, and offers custom synthesis services for special applications. Omicron serves thousands of clients worldwide, and presently prepares materials ranging from reagent grade to cGMP-grade appropriate for human clinical trials. The impact of this entrepreneurial effort with respect to supporting and promoting scientific research in many diverse fields has been enormous. Dr. Serianni still serves as President and CEO of Omicron, and oversees the technical aspects of its operations and the development of new products and services.

Key Papers:

B. Academic Career, 1982-1992. This period of Professor Serianni’s professional career focused mainly on the development of NMR methods to investigate the structures and reactivities of saccharides. Three main themes emerge from this body of work: (a) NMR-based kinetics measurements of saccharide anomerization; (b) the application of stable isotopes to investigate in vivo biological metabolism; and (c) the application of ab initio molecular orbital calculations to investigate saccharide structure and conformation.

Professor Serianni was the first to recognize that saturation–transfer NMR methods could be used to measure the unidirectional rate constants (as opposed to complex rate constants) of aldose anomerization in solution. The method hinges on the selective saturation of the acyclic carbonyl form of the aldose, or more specifically, the anomeric proton or carbon of the acyclic form, even though it comprises only a small percentage of the total forms (tautomers) present in solution (typically less than 1%). By measuring the rate of transfer of saturation to the cyclic forms (detected as a loss of signal intensity with increasing saturation time), first-order ring-opening rate constants for each cyclic form in solution can be measured. From the individual equilibrium constants also measured by NMR, ring-closing rate constants could be determined, thus fully defining these complex systems kinetically. The same methodology was applied to ketoses by limiting the experiment to carbon detection (e.g., C2 of fructose). The Serianni lab showed that furanose ring anomeric configuration controls the relative rates of ring-opening, with O1-O1 cis arrangements leading to enhanced ring-opening, presumably through an anchimeric assistance mechanism. In subsequent studies with phosphorylated sugars, his group showed the importance of intramolecular catalysis by phosphate in promoting anomerization, demonstrating that the magnitude of this catalysis is affected by ring configuration. These latter studies have important implications for biological metabolism when sugar phosphates are involved as metabolites; since many enzymes bind only one anomer, rates of anomerization can play a potential role in determining metabolic flux through some pathways (anomeric control).

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In a second line of investigation, Professor Serianni collaborated with Professor John Duman (Biological Sciences, Notre Dame) to develop stable-isotope based NMR tools to investigate sugar metabolism in a freeze-tolerant organism, Gynophora groenlandica. The Serianni lab designed a 16-mm 13C NMR probe into which live larvae, injected with labeled saccharides, were inserted, and real-time, non-invasive monitoring of the labeled sugar was performed. These in vivo studies were complemented by in vitro experiments where specific organs of the larvae were extracted and incubated with labeled sugars to elucidate pathways of metabolism. This work provided new insights in the metabolic triggers that promote the production of polyols such as glycerol in freeze-tolerant organisms, and provided new insights into the effects of hypoxia/anoxia, mitochondrial biogenesis and degradation, and other factors on cryoprotectant production in vivo. The results of these studies are of particular interest for the preservation of human organs for transplant purposes. This collaboration is still active, and recent work will be highlighted later in this summary.

Key Papers:

The third line of investigation in the early Serianni lab involved the use of ab initio molecular orbital theory to investigate saccharide structure and conformation. Before this work, little if any application of this theory had been applied to saccharides. The first publication appeared in 1987, in which the now crude (but then relatively sophisticated) STO-3G level of ab initio MO calculations was applied to structure/conformational studies of the tetrofuranose ring system. To conduct this work, Dr. Serianni collaborated with Dr. Daniel Chipman, who at that time was heavily involved with MO methods development and was a colleague in the Radiation Laboratory at Notre Dame. This new theoretical tool later became an integral part of the third research phase of the Serianni lab (1993 – present; see below) in which DFT calculations were not only used to predict structural features, but also to predict NMR parameters which could be used to assist in the analysis of experimental NMR data, from which a experimentally based structure could be deduced.

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C. Academic Career, 1993-present. The most recent period of research in the Serianni laboratory has focused mainly, but not exclusively, on the development of NMR spin-couplings as quantitative probes of saccharide structure and conformation in solution. This work was initiated in 1993 with the publication of a paper in JACS showing a Karplus-like relationship for 1JCC in saccharides; this study demonstrated the power of combining NMR studies with stable isotopes, and ab initio MO calculations, to investigate spin-coupling behaviors in these systems. This work was done in collaboration with Dr. Ian Carmichael of the Radiation Laboratory at Notre Dame. Since that time, the Serianni-Carmichael team has published over 50 papers on the characterization of NMR J-couplings in saccharides experimentally and theoretically (DFT), thereby extensively re-defining the importance and utility of carbon-based J-couplings (JCH and JCC) in saccharides. For example, in 1995, the Serianni-Carmichael team demonstrated the use of 1JCH values as conformational probes of furanose rings, and showed how these couplings respond to C-H bond orientational effects (pseudo-axial/pseudo-equatorial) and C-O bond rotations (vicinal lone-pair effects) in these ring systems. In 1998, this team published the first 3JCOCC Karplus curve relevant to the analysis of 3JCOCC values across O-glycosidic linkages. In this detailed work, they demonstrated the importance of terminal electronegative substituent effects on coupling magnitude and set the stage for quantitative interpretations of these couplings as a means of establishing linkage conformation in solution. In 2004, the Serianni group showed that J-couplings could be used to determine correlated conformations of exocyclic hydroxymethyl groups, since some of these couplings depend on two torsion angles. In 2005, 2JCCH values in saccharides were shown to depend heavily on C-O bond rotations involving the carbon bearing the coupled proton, leading to a new conformational constraint for O-glycosidic linkages. In 2006, Serianni’s group showed how 1JCH could be used to measure the strengths of H-bonds in aqueous solution, introducing the concept of “functional” J-couplings. In 2008, Serianni’s group demonstrated quantitatively the effect of internal electronegative substituents on 3JCOCC values, thus further defining the structural dependencies of these important NMR constraints. Most recently, the Serianni group has developed a new mathematical treatment of J-coupling ensembles (MA’AT) to calculate phi and psi populations in glycosidic linkages, thus providing experimentally based populations to validate MD predictions.

The Serianni group most recently has embarked on mechanistic studies of saccharide degradation using stable isotopes and NMR. Two studies are highlighted here. In 2011, they showed that the dicarbonyl sugar, 3-deoxyglucosone (3DG), degrades in aqueous solution via a 1,2-hydrogen transfer mechanism to give C2-epimeric metasaccharinic acids. This work follows up their prior work (Biochemistry, 2008) on the effect of pyridoxamine on 3DG degradation. These studies are relevant to diabetes mellitus, where high concentrations of glucose in blood and plasma result in the in vivo production of 3DG, which then inflicts cellular/tissue damage via protein glycation and other deleterious reactions. Very recently (2012), the Serianni group has discovered a novel rearrangement of the dicarbonyl sugar, D-glucosone, in which the molecule undergoes C1-C2 transposition during conversion to D-ribulose. This finding provides a second example of a reaction in saccharide chemistry in which C1-C2 transposition takes place (see molybdate reaction above).
Finally, in recent work performed in collaboration with Professor John Duman’s research group in the Department of Biological Sciences at Notre Dame, the Serianni team elucidated the structure of a novel non-protein thermal hysteresis compound built on a xylo-mannan oligosaccharide scaffold. This finding has recently been patented.

Key Papers:

Year-by-Year Descriptors of Key Research Results

1977: Early use of glycolytic enzymes in the synthesis of stable isotopically labeled carbohydrates

1979: First description of the cyanohydrin reduction method for 13C-labeling of aldohexoses, aldopentoses, aldotetroses, glyceraldehyde and glycolaldehyde

1980: Modification of the cyanohydrin reduction method to prepare 2H-labeled aldoses

1980: Integrated use of trans-O-glycoside 3JCOCH and 3JCOCC in oligosaccharide conformational analysis

1982: First description of NMR saturation-transfer to measure unidirectional rate constants of anomerization of aldofuranoses; structure/reactivity relationships in furanose anomerization

1982: Elucidation of unique molybdate-catalyzed rearrangement mechanism of aldose C2-epimerization

1982: Chemo-enzymic synthesis of various isotopically labeled saccharides

1982: Commercialization of the cyanohydrin reduction technology; founding of Omicron Biochemicals Inc.

1983: Synthesis of saccharides containing chiral (deuterated) hydroxymethyl groups

1984: Description of the integrated use of JHH, JCH and JCC in the conformational analysis of furanosyl rings

1986: Experimental measurements of unidirectional rates of anomerization in aldopyranoses

1987-1992: Systematic investigations of JCC in aldoses

1987: First molecular orbital calculations on intact aldofuranose rings

1988-1990: Synthesis and NMR investigations of nucleosides containing chirally-deuterated hydroxymethyl groups

1988-1994: In vivo NMR studies of freeze tolerance in lepidoptera

1990-1997: NMR studies of JCH and JCC in nucleosides

1990: Development of an automated synthesizer of labeled saccharides

1988-1991: Studies of Thorpe-Ingold effects in aldoses; refined structure/reactivity relationships in furanose and pyranose anomerization; synthesis of labeled ketoses; ketose anomerization

1990-1992: Description of cross-peak displacement method for measuring J-couplings in saccharides; use of homonuclear 2D J-spectroscopy to measure JCH in labeled saccharides; use of 2D 13C exchange spectroscopy to measure overall rates of anomerization; application of DESERT method in oligosaccharide conformational analysis

1993: First investigation of 1JCC in saccharides; correlations with molecular torsion angles

1994: Early NMR study of site-specifically labeled oligodeoxyribonucleotides (CCAAT sequences)

1995: Systematic study of JCH in methyl aldopyranosides

1995: Description of 1JCH as a conformational probe in aldofuranosyl rings

1996-2000: Development of the projection resultant rule to interpret 2JCOC in saccharides; measurement of 2JCCC and 2JCOC coupling signs by 13C-13C COSY-45 in triply-labeled saccharides; elucidation of the effect of COC bond-angle on 2JCOC magnitude

1996-1997: First systematic experimental and theoretical analyses of JCH and JCC in the beta-D-ribofuranosyl and 2-deoxy-beta-D-ribofuranosyl rings

1997-2000: Quantum mechanical studies of the effect of ring-oxygen and N1 protonation on the molecular structures of aldofuranoses and aldofuranosylamines

1998: Quantification of cyclic and acyclic forms of aldopentoses in solution; description of isotope-edited HMQC-TOCSY applications in saccharides

1998: Development of a new Karplus relationship for 3JCOCC in saccharides; applications in oligosaccharides

1999: First theoretical (DFT) treatment of 3JCOCC across O-glycosidic linkages

2000: Studies of JHH, JCH and JCC in conformationally-constrained Pt-saccharide complexes

  • H. Junicke, A.S. Serianni and D. Steinborn, Platinum(IV)-Carbohydrate Complexes: Structure Determination Based on 1H-1H, 13C-1H and 13C-13C Spin-Spin Coupling Constants. J. Org. Chem. 2000, 65, 4153-4161.

    2000: First systematic investigation of 2H quadrupolar coupling constants in saccharides

    2000: Theoretical study of N-substitution effects on structure, conformation and J-couplings in aldofuranoses















    Last Update: 02/07/16