SpectRIM: Scientific Publications-Presentations

2005

1. "The Use of Raman Spectroscopy in the Detection of Counterfeit and Adulterated Pharmaceutical Products", Mark R. Witkowski, Ph.D., American Pharmaceutical Review, Jan/Feb 2005, 1-5

2. "New Dimensions in Pharmaceutical Diagnostics", Corasi Ortiz" Penelope Cipriani, Ph.D., Yong Xie, Xiuping Liu, Dongmao Zhang, Ph.D., Gotam K. Jarori, Ph.D. and Dor Ben-Amotz, Ph.D., American Pharmaceutical Review, 2004, 30-35

4. "Characterization of select members of the Taxane family using Raman spectroscopy", Penelope Cipriani and Dor Ben-Amotz, JOURNALOF RAMAN SPECTROSCOPY, 2005, ASAP

Abstract:  Experimentally derived Raman spectra of three members of the taxane family are presented and discussed. The taxoids investigated were docetaxel (Taxotere ® ), baccatin III and cephalotaxine. These analytes were studied because of their potent antitumor capability or they are potential precursors for the synthesis of highly valuable pharmaceutical drugs. Drop coating deposition Raman (DCDR) spectroscopy is utilized in order to examine the vibrational wavenumbers of the powders and solutions, down to concentrations as low as 1 μM. Normal Raman modes of two of the three taxanes are confirmed by comparing experimental spectra with related literature and quantum mechanical ab initio calculations.

2004

1. " The Raman Detection of Peptide Tyrosine Phosphorylation", Yong Xie, Dongmao Zhang, Gotam K. Jarori, V. Jo Davisson and Dor Ben-Amotz, Analytical Biochemistry 332 (2004) 116–121.

Abstract: Drop-coating-deposition-Raman (DCDR) is used to detect spectral changes induced by phosphorylation of tyrosine amino acid residues in peptides. Four peptides are investigated, with sequences derived from the human protein-tyrosine kinase, p60c-src, with Y-216, Y-419, and Y-530 phosphorylation sites. Although the spectra of the four peptides are quite di V erent, tyrosine phosphorylation is found to invariably induce the collapse of a doublet at 820–850 cm¡1 and the attenuation of a peak around 1205 cm¡1. Moreover, amide III band shifts suggest that tyrosine phosphorylation may promote _ sheet formation, particularly in peptides that lack phenylalanine residues. The degree of tyrosine phosphorylation in peptide mixtures is determined using DCDR combined with partial least squares multivariate calibration with a 2% root mean standard error of prediction.

2. " Identification of Insulin Variants using Raman Spectroscopy ", Corasi Ortiz, Dongmao Zhang, Yong Xie, V. Jo Davisson, and Dor Ben-Amotz, Anal. Biochem., 332, 245–252 (2004).

Abstract: Drop coating deposition Raman (DCDR) spectroscopy is used to obtain high-quality normal Raman spectra from small volumes (10ll) of dilute insulin solutions (3–400lM) for spectral identification and chromatographic detection. The results are used to demonstrate the spectroscopic classification (identification) of three natural insulin variants—human, bovine, and porcine—that differ by between one and three amino acid residues. DCDR measurements were performed on solutions obtained from reverse phase high-performance liquid chromatography (RP-HPLC) eluent fractions, either before or after lyophilization. Classification is demonstrated using replicate DCDR measurements, followed by normalized Savitsky–Golay second derivative preprocessing and partial least squares training with either leave-one-out or batch-to-batch testing.

3. " Chemical Segregation and Reduction of Raman Background Interference Using Drop Coating Deposition ", Dongmao Zhang, Melissa F. Mrozek, Yong Xie, and Dor Ben-Amotz. APPLIED SPECTROSCOPY, Volume 58, Number 8, 2004, 929-93.

Abstract: A new application of the recently described drop coating deposition Raman (DCDR) method facilitates the segregation and independent spectral characterization of mixture components. The quality of the normal (un-enhanced) Raman spectra are significantly improved as a result of reduced spectral interference from fluorescent impurities and buffer compounds. Fluorescence of commercial amino acid (Ophospho-L-serine) and protein (myoglobin) samples is reduced by over an order of magnitude using DCDR, more effectively than prolonged photo-bleaching. Furthermore, DCDR is used to obtain high-quality Raman spectra of proteins, lysozyme, and insulin, derived from solutions with up to 1000-fold excess buffer concentration. Possible thermodynamic and kinetic contributions to the observed segregation phenomena are discussed.

4. "New Substrate for Raman, Infrared and Mass Spectroscopic –Chemical Analysis", Dongmao Zhang, Yong Xie, Dor Ben-Amotz and Raymond F DeGrella, B usiness Briefing: L A B T E C H 2 0 0 4, 49-52

2003

1. " New Dimensions in Proteomic Sensing", D. Ben-Amotz, D. Zhang, V. Shalaev, V. Drachev, Federation of Analytical Chemistry and Spectroscopy Societies, October 21, 2003.

Abstract: The Indiana Proteomic Consortium was founded in 2002 by Eli Lilly, Purdue University and Indiana University In order to promote the development of new protein sensing instruments.  One branch of the effort is focused on evaluating the potential of Raman/SERS as a proteomic sensing technology for bio-medical/pharmaceutical diagnostics. The talk presents the results of the successful first year pilot project phase of this major ongoing research and development effort

The complexity of proteins, particularly with regard to post translational modifications such as phosphorylations and glycosylation, poses a significant challenge to existing chromatographic, mass spectral and fluorescence based proteomic separation and diagnostic technologies. The high chemical information content of Raman spectroscopy provides a valuable orthogonal dimension of chemical information pertaining to primary, secondary and tertiary structural changes. Examples of compounds that are impossible to differentiate by mass spec (without further chemical processing) include peptides and proteins of the same mass that are phosphorylated at different sites of glycans (sugars) of the same mass with different branching structures. Since Raman is sensitive to even subtle changes in bonding and branching it is capable of distinguishing such structure differences. However, conventional Raman detection methods are not compatible with many proteomic applications, as these are often require analysis samples available in very small quantities and/or low concentrations.

This talk reports recent progress made in implementing new sample handling and micro-Raman sensing methods for the analysis of such samples. These demonstrate that high quality Raman spectra of proteins, peptides and glycans can be obtained from solutions with uM to mM analyte concentrations, even in the presence of up to 100-fold excess of strongly Raman active buffer compounds. Results include the detection of amol to fmol quantities of protein (probe by the Raman excitation laser beam) well as demonstrations of the Raman-based classifications (identification) of peptides/proteins conformational changes and post-translational modifications, glycan isomers of different branching, structure and quantification of the composition of glycan mixtures. These results are based on statistically significant (leave one-batch-out) tests using multivariate analysis of spectra collected form independently prepared samples.

2. " Raman Detection of Proteomic Analytes", D. Zhang, Y. Xie, M. F. Mrozek, C. Ortiz, V. J. Davisson, and D. Ben-Amotz, Anal. Chem.2003, 75, 5703-5709.

Abstract: The compatibility of nonenhanced Raman spectroscopy with chromatographic and mass spectroscopic proteomic sensing is demonstrated for the first time. High-quality normal Raman spectra are derived from protein solutions with concentrations down to 1 íM and 1 fmol of protein nondestructively probed within the excitation laser beam. These results are obtained using a drop coating deposition Raman (DCDR) method in which the solution of interest is microdeposited (or microprinted) on a compatible substrate, followed by solvent evaporation and backscattering detection. Representative applications include the DCDR detection of insulin derived from an HPLC fraction, nondestructive DCDR followed by MALDI-TOF of lysozyme, the DCDR detection of protein spots deposited using an ink-jet microprinter, and the identification of spectral differences between glycan isomers of equal mass (such as those derived from posttranslationally modified proteins).