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Pi-Boleda B, Bouzas M, Gaztelumendi N, Illa O, Nogués C, Branchadell V, Pons R, Ortuño RM. Chiral pH-sensitive cyclobutane β-amino acid-based cationic amphiphiles: Possible candidates for use in gene therapy. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.111856] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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2
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Raghavan V, Polavarapu PL. Specific optical rotation is a versatile tool for the identification of critical micelle concentration and micellar growth of tartaric acid-based diastereomeric amphiphiles. Chirality 2017; 29:836-846. [PMID: 28991388 DOI: 10.1002/chir.22767] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/14/2017] [Accepted: 08/29/2017] [Indexed: 11/09/2022]
Abstract
Four novel tartaric acid-based diastereomeric chiral amphiphiles, two being enantiomers of the other two, have been synthesized and investigated using chiroptical spectroscopic methods, along with tensiometry and dynamic light scattering experiments. We found that an inflection point in specific optical rotation (SOR) values at ~0.32 mM corresponds to the critical micelle concentration (CMC). The increase in magnitude of SOR values beyond CMC corresponds to the growth of aggregates. For enantiomers, oppositely signed SOR values were observed, ruling out the possibility for the presence of aggregation size mediated artefacts. SOR values did not exhibit concentration dependence for a chiral tartaric acid based non-aggregating analogue further establishing the absence of artefacts or anomalous interaction of tartaric acid based head group with solvent. Electronic circular dichroism spectra showed no significant changes in band positions or intensities with concentration. Due to the requirement for higher concentrations (~200 mM) needed to obtain vibrational circular dichroism spectra, these measurements are not found to be useful for studying concentration dependent properties of chiral amphiphiles.
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Affiliation(s)
- Vijay Raghavan
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
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3
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Merten C. Vibrational optical activity as probe for intermolecular interactions. Phys Chem Chem Phys 2017; 19:18803-18812. [DOI: 10.1039/c7cp02544k] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A detailed VCD spectroscopic analysis of well-selected chiral model systems can give valuable and unprecedented insights into intermolecular interactions such as solvation or reactant–substrate binding in catalysis.
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4
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Kononov LO, Fedina KG, Orlova AV, Kondakov NN, Abronina PI, Podvalnyy NM, Chizhov AO. Bimodal concentration-dependent reactivity pattern of a glycosyl donor: Is the solution structure involved? Carbohydr Res 2016; 437:28-35. [PMID: 27883907 DOI: 10.1016/j.carres.2016.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 11/30/2022]
Abstract
Changes in concentration (0.001-0.1 M) of an arabinofuranosyl donor (1) have been shown to modulate the temperature T at which activation of 1 occurs (from -23 °C to +7 °C), the reaction time (from 1.5 h to 3 days) and the yield of the disaccharide formed (from 14% to 82%). At concentrations exceeding 0.01 M, these parameters, as well as the specific optical rotation of the solution of 1, virtually do not depend on concentration suggesting formation of reacting species (supramers) of glycosyl donor with similar structures, hence reactivities, but considerably different from those formed in more dilute solutions. The found critical concentration (0.01 M) separates two concentration ranges of reaction solutions corresponding to two types of solution structure that are featured by the presence of fundamentally different supramers of glycosyl donor, which have distinct chemical properties. These results allow a fresh look at the problems of reactivity of chemical compounds and selectivity of the reactions in which they participate.
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Affiliation(s)
- Leonid O Kononov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation.
| | - Ksenia G Fedina
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Anna V Orlova
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Nikolay N Kondakov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Polina I Abronina
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Nikita M Podvalnyy
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
| | - Alexander O Chizhov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp., 47, 119991, Moscow, Russian Federation
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5
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Emile O, Emile J, Ghoufi A. Influence of the interface on the optical activity of confined glucose films. J Colloid Interface Sci 2016; 477:103-8. [PMID: 27254252 DOI: 10.1016/j.jcis.2016.05.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/23/2016] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
Abstract
We report on the time evolution of the optical activity of a thinning liquid film containing glucose, and confined between two glass slides. This dynamics strongly depends on the presence of surfactant molecules. With sodium dodecyl sulfate (SDS), we evidence favorable interactions of sugar molecules with the sulfate group. As previously observed for a freely suspended soap film in the air (see Emile et al., 2013), this corresponds to an anchoring of glucose molecules at the interface. For glucose alone, we also highlight a molecular rearrangement that is not instantaneous and occurs after several minutes. This interfacial organization leads to an unusual giant optical activity that is different with or without SDS. Molecular simulations confirm the anchoring of the glucose molecules at the glass/liquid interface, and show a different molecular orientation in each case.
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Affiliation(s)
- Olivier Emile
- Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France.
| | - Janine Emile
- Institut de Physique de Rennes, CNRS UMR 6521, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France
| | - Aziz Ghoufi
- Institut de Physique de Rennes, CNRS UMR 6521, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France
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6
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Covington CL, Polavarapu PL. Concentration Dependent Specific Rotations of Chiral Surfactants: Experimental and Computational Studies. J Phys Chem A 2016; 120:5715-25. [PMID: 27355395 DOI: 10.1021/acs.jpca.6b05039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent experimental studies have shown unexpected chiroptical response from some chiral surfactant molecules, where the specific rotations changed significantly as a function of concentration. To establish a theoretical understanding of this experimentally observed phenomena, a novel methodology for studying chiral surfactants via combined molecular dynamics (MD) and quantum mechanical (QM) calculations is presented. MD simulations on the +10 000 atom surfactant systems have been performed using MD and QM/molecular mechanics (MM) approaches. QM calculations performed on MD snapshots coupled with extensive analysis on lauryl ester of phenylalanine (LEP) surfactant system indicate that the experimentally observed variation of specific rotation with concentration may be due to the conformational differences of the surfactant monomers in the aggregates. Though traditional MM simulations did not show significant differences in the conformer populations, QM/MM simulations using the forces derived from the PM6 method did predict conformational differences between aggregated and nonaggregated LEP molecules, which is consistent with experimental data. Additionally the electrostatic environment of charged surfactants may also be important, since dramatic changes in the Boltzmann populations of surfactant monomers can be noted in the presence of an electric field generated by the chiral ionic aggregates.
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Affiliation(s)
- Cody L Covington
- Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Prasad L Polavarapu
- Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States
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7
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Reddy SMM, Shanmugam G, Duraipandy N, Kiran MS, Mandal AB. An additional fluorenylmethoxycarbonyl (Fmoc) moiety in di-Fmoc-functionalized L-lysine induces pH-controlled ambidextrous gelation with significant advantages. SOFT MATTER 2015; 11:8126-8140. [PMID: 26338226 DOI: 10.1039/c5sm01767j] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In recent years, several fluorenylmethoxycarbonyl (Fmoc)-functionalized amino acids and peptides have been used to construct hydrogels, which find a wide range of applications. Although several hydrogels have been prepared from mono Fmoc-functionalized amino acids, herein, we demonstrate the importance of an additional Fmoc-moiety in the hydrogelation of double Fmoc-functionalized L-lysine [Fmoc(Nα)-L-lysine(NεFmoc)-OH, (Fmoc-K(Fmoc))] as a low molecular weight gelator (LMWG). Unlike other Fmoc-functionalized amino acid gelators, Fmoc-K(Fmoc) exhibits pH-controlled ambidextrous gelation (hydrogelation at different pH values as well as organogelation), which is significant among the gelators. Distinct fibrous morphologies were observed for Fmoc-K(Fmoc) hydrogels formed at different pH values, which are different from organogels in which Fmoc-K(Fmoc) showed bundles of long fibers. In both hydrogels and organogels, the self-assembly of Fmoc-K(Fmoc) was driven by aromatic π-π stacking and hydrogen bonding interactions, as evidenced from spectroscopic analyses. Characterization of Fmoc-K(Fmoc) gels using several biophysical methods indicates that Fmoc-K(Fmoc) has several advantages and significant importance as a LMWG. The advantages of Fmoc-K(Fmoc) include pH-controlled ambidextrous gelation, pH stimulus response, high thermal stability (∼100 °C) even at low minimum hydrogelation concentration (0.1 wt%), thixotropic property, high kinetic and mechanical stability, dye removal properties, cell viability to the selected cell type, and as a drug carrier. While single Fmoc-functionalized L-lysine amino acids failed to exhibit gelation under similar experimental conditions, the pH-controlled ambidextrous gelation of Fmoc-K(Fmoc) demonstrates the benefit of a second Fmoc moiety in inducing gelation in a LMWG. We thus strongly believe that the current findings provide a lead to construct or design various new synthetic Fmoc-based LMW organic gelators for several potential applications.
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Affiliation(s)
- Samala Murali Mohan Reddy
- Bioorganic Laboratory, Council of Scientific and Industrial Research - Central Leather Research Institute, Adyar, Chennai 600020, India.
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Draper ER, Morris KL, Little MA, Raeburn J, Colquhoun C, Cross ER, McDonald TO, Serpell LC, Adams DJ. Hydrogels formed from Fmoc amino acids. CrystEngComm 2015. [DOI: 10.1039/c5ce00801h] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A number of Fmoc amino acids can be effective low molecular weight hydrogelators; we compare single crystal structures to fibre X-ray diffraction data.
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Affiliation(s)
| | | | - Marc A. Little
- Department of Chemistry
- University of Liverpool
- Liverpool, UK
| | - Jaclyn Raeburn
- Department of Chemistry
- University of Liverpool
- Liverpool, UK
| | | | - Emily R. Cross
- Department of Chemistry
- University of Liverpool
- Liverpool, UK
| | | | | | - Dave J. Adams
- Department of Chemistry
- University of Liverpool
- Liverpool, UK
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9
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Abbate S, Passarello M, Lebon F, Longhi G, Ruggirello A, Turco Liveri V, Viani F, Castiglione F, Mendola D, Mele A. Chiroptical Phenomena in Reverse Micelles: The Case of (1R,2S)-Dodecyl (2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium Bromide (DMEB). Chirality 2014; 26:532-8. [DOI: 10.1002/chir.22309] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/23/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Sergio Abbate
- Dipartimento di Medicina Molecolare e Traslazionale; Università di Brescia; Brescia Italy
- Consorzio Interuniversitario Scienze Fisiche della Materia; Roma Italy
| | - Marco Passarello
- Dipartimento di Medicina Molecolare e Traslazionale; Università di Brescia; Brescia Italy
- Department of Chemistry; Materials and Chemical Engineering “G. Natta,” Politecnico di Milano; Milano Italy
| | - France Lebon
- Dipartimento di Medicina Molecolare e Traslazionale; Università di Brescia; Brescia Italy
- Consorzio Interuniversitario Scienze Fisiche della Materia; Roma Italy
| | - Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale; Università di Brescia; Brescia Italy
- Consorzio Interuniversitario Scienze Fisiche della Materia; Roma Italy
| | - Angela Ruggirello
- Dipartimento di Chimica; Università degli Studi di Palermo; Palermo Italy
- ISMN; Istituto per lo Studio dei Materiali Nanostrutturati; Palermo Italy
| | - Vincenzo Turco Liveri
- Dipartimento di Chimica; Università degli Studi di Palermo; Palermo Italy
- ISMN; Istituto per lo Studio dei Materiali Nanostrutturati; Palermo Italy
| | - Fiorenza Viani
- Istituto di Chimica del Riconoscimento Molecolare - CNR; Milano Italy
| | - Franca Castiglione
- Department of Chemistry; Materials and Chemical Engineering “G. Natta,” Politecnico di Milano; Milano Italy
| | - Daniele Mendola
- Department of Chemistry; Materials and Chemical Engineering “G. Natta,” Politecnico di Milano; Milano Italy
| | - Andrea Mele
- Department of Chemistry; Materials and Chemical Engineering “G. Natta,” Politecnico di Milano; Milano Italy
- Istituto di Chimica del Riconoscimento Molecolare - CNR; Milano Italy
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10
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Orlova AV, Andrade RR, da Silva CO, Zinin AI, Kononov LO. Polarimetry as a tool for the study of solutions of chiral solutes. Chemphyschem 2013; 15:195-207. [PMID: 24357041 DOI: 10.1002/cphc.201300894] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 11/06/2022]
Abstract
Optical rotation of aqueous solutions of D-levoglucosan was studied experimentally in the 0.03-4.0 mol L(-1) concentration range and a nonlinear concentration dependence of specific optical rotation (SR) was revealed. Discontinuities observed in the concentration plot of SR (at 0.1, 0.3, 0.5, 1.0, and 2.0 mol L(-1)) are well correlated with those found by static and dynamic light scattering and identify concentration ranges in which different solution domains (supramers) may exist. The average SR experimental value for a D-levoglucosan aqueous solution ([α]D(28) -58.5±8.7 deg dm(-1) cm(-3) g(-1)) was found to be in good agreement with values obtained by theoretical calculation (TD-DFT/GIAO) of SR for 15 different conformers revealed by conformational sampling at the PCM/B3LYP/6-311++G(2d,2p)//B3LYP/6-31+G(d,p) level, which were shown to be strongly affected by the solvation microenvironment (0, 1, 2, and 3 explicit solvent molecules considered) due to local geometrical changes induced in the solute molecule. This exceptionally high sensitivity of SR makes polarimetry a unique method capable of sensing changes in the structure of supramers detected in this study.
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Affiliation(s)
- Anna V Orlova
- N. K. Kochetkov Laboratory of Carbohydrate Chemistry, N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, 11991 Moscow (Russian Federation), Fax: (+7) 499-135-5328
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11
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Vijay R, Baskar G, Mandal AB, Polavarapu PL. Unprecedented relationship between the size of spherical chiral micellar aggregates and their specific optical rotations. J Phys Chem A 2013; 117:3791-7. [PMID: 23574486 DOI: 10.1021/jp401544g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Transmission electron microscopy (TEM) images and fluorescence quenching methods indicated that lauryl ester of L-phenylalanine (LEP) and lauryl ester of L-tyrosine (LET) form spherical chiral micelles in the 50-200 mM range and their size increases with concentration. The number of molecules present in these spherical chiral aggregates varied from 80 to 160 for LEP and 80-100 for LET. The specific optical rotation, representing circular birefringence, for LEP at 405 nm and 32 °C is found to increase linearly from 37 deg cc g(-1) dm(-1) for an isolated molecule to 56 deg cc g(-1) dm(-1) for ∼200 nm size aggregate. A similar trend was found for temperatures up to 70 °C and at other visible wavelengths. A linear relation between specific optical rotation and the size of aggregate is also observed for LET. Circular dichroism, as measured in both the visible and infrared wavelength regions, however did not reveal any concentration dependent changes. The unique sensitivity uncovered for specific optical rotation as a function of the size of spherical chiral aggregates is unprecedented and opens new areas of enquiry for physical chemists.
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Affiliation(s)
- R Vijay
- Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States
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12
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Vijay R, Polavarapu PL. FMOC-Amino Acid Surfactants: Discovery, Characterization and Chiroptical Spectroscopy. J Phys Chem A 2012; 116:10759-69. [DOI: 10.1021/jp308134m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- R. Vijay
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United
States
| | - Prasad L. Polavarapu
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United
States
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13
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Polavarapu PL, Donahue EA, Hammer KC, Raghavan V, Shanmugam G, Ibnusaud I, Nair DS, Gopinath C, Habel D. Chiroptical spectroscopy of natural products: avoiding the aggregation effects of chiral carboxylic acids. JOURNAL OF NATURAL PRODUCTS 2012; 75:1441-1450. [PMID: 22877358 DOI: 10.1021/np300341z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Determination of the absolute configurations and predominant conformations of chiral natural products, occurring as carboxylic acids, using chiroptical spectroscopic methods becomes challenging due to the formation of solute aggregates (in the form of dimers, etc.) and/or solute-solvent complexes resulting from intermolecular hydrogen bonding with solvent. A hypothesis that such aggregation effects can be avoided by using corresponding sodium salts or acid anhydrides for chiroptical spectroscopic measurements has been tested. For this purpose, vibrational circular dichroism, electronic circular dichroism, and optical rotatory dispersion spectra for disodium salts of two natural products, hibiscus acid and garcinia acid, and the anhydride of acetylated garcinia acid have been measured. These experimental spectra are analyzed in combination with quantum chemical calculations of corresponding spectra. The spectral analysis for sodium salts and anhydride turned out to be simpler, suggesting that the conversion of carboxylic acids to corresponding salts or anhydride can be advantageous for the application of chiroptical spectroscopy.
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14
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Haleema S, Sasi PV, Ibnusaud I, Polavarapu PL, Kagan HB. Enantiomerically pure compounds related to chiral hydroxy acids derived from renewable resources. RSC Adv 2012. [DOI: 10.1039/c2ra21205f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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