Enantioseparation of selected chiral sulfoxides using polysaccharide-type chiral stationary phases and polar organic, polar aqueous-organic and normal-phase eluents

Separation of isotopologues of amphetamine with various degree of deuteration on achiral and polysaccharide-based chiral columns in high-performance liquid chromatography

Hydrogen/deuterium (H/D) isotope effects are not unusual in chromatography and such phenomena have been observed in both gas- and liquid-phase separations. Despite the numerous reports on this topic, the understanding of mechanisms and the underlying noncovalent interactions at play remains rather challenging. In our recent study, we reported baseline separation of isotopologoues of some amphetamine (AMP) derivatives on achiral and polysaccharide-based chiral columns, as well as some correlations between the degree of separation of enantiomers and isotopologues on (the same) polysaccharide-based chiral column(s). Following our previous findings on isotope effects in high-performance liquid chromatography, we report herein a comparative study on the isotope effects observed with AMP and methamphetamine (MET). The impact of some pivotal factors such as the number of deuterium atoms part of AMP isotopologues, the structure of its isotopomers, the chemical structure of the achiral and chiral stationary phases used in this study, and the use of methanol- vs acetonitrile-containing mobile phases on the isotope effects was examined and discussed. Quantitative correlations between the observed isotope effects and the enantioselectivity of the chiral columns used are also shortly discussed. Furthermore, considering the chromatographic results as benchmark experimental data, we attempted to elucidate the molecular bases of the observed phenomena using quantum mechanics calculations.

Separation of undeuterated and partially deuterated enantioisotopologues of some amphetamine derivatives on achiral and polysaccharide-based chiral columns in high-performance liquid chromatography

The different behavior of enantiomers of chiral compounds in non-isotropic environments (among them in living organism) is well known. On the other hand, the importance of a kinetic isotope effect in the biomedical field has become evident during past few decades. Thus, separation of both, enantiomers and isotopologues is now critical. Only very few published studies have attempted the simultaneous separation of enantioisotopologues. In this article we report baseline separation of partially deuterated isotopologues of a few amphetamine derivatives in high-performance liquid chromatography (HPLC) using achiral columns. In addition, the simultaneous separations of enantiomers and isotopologues (i.e. enantioisotopologues) were attempted on polysaccharide-based chiral columns. For several compounds the isotope effect was tunable and could be switched from a "normal" to "inverse" by making changes to the mobile-phase composition. A stronger isotope effect was observed in acetonitrile-containing mobile phases compared to methanol-containing ones with both chiral and achiral columns. In a separation system where both "normal" and "inverse" isotope effects were observed the "normal" isotope effect was favored in polar organic solvents while increasing content of the aqueous component in the reversed-phase (RP) mobile phase favored an "inverse" isotope effect. This observation indicates that polar, hydrogen bonding-type noncovalent interactions are involved in the "normal" isotope effect, while apolar hydrophobic-type interactions are mostly responsible for the "inverse" isotope effect.

Understanding the Transition from High-Selective to High-Efficient Chiral Separations by Changing the Organic Modifier with Zwitterionic-Teicoplanin Chiral Stationary Phase

The retention behavior of small molecules and N-protected amino acids on a zwitterionic teicoplanin chiral stationary phase (CSP), prepared on superficially porous particles (SPPs) of 2.0 μm particle diameter, has shown that efficiency and enantioselectivity, and so enantioresolution, dramatically change depending on the employed organic modifier. In particular, it was found that while methanol permits the boost of enantioselectivity and resolution of the amino acids, at the cost of efficiency, acetonitrile allows for the ability to reach extraordinary efficiency even at high flow rates (with reduced plate height <2 and up to 300,000 plates/m at the optimum flow rate). To understand these features, an approach based on the investigation of mass transfer through the CSP, the estimation of the binding constants of amino acids on the CSP, and the assessment of compositional properties of the interfacial region between bulk mobile phase and solid surface has been adopted.

Effect of mobile-phase modifiers on the enantioselective retention behavior of methyl mandelate with an amylose 3,5-dimethylphenylcarbamate chiral stationary phase under reversed-phase conditions

In this study, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, acetone, and tert-butanol were used as organic modifiers in reversed-phase mode chiral liquid-chromatography to systematically investigate the effects of mobile phase components on the enantioselective retention behavior of methyl mandelate with immobilized amylose 3,5-dimethylphenylcarbamate-based sorbent called Chiralpak IA. A two-site enantioselective model was used to obtain information on the recognition mechanisms by observing the dependence of the enantioselectivity and retention factor difference on the modifier content. Similar enantioselective retention behaviors were observed for all modifiers, and characteristic modifier concentration points (P_L , P_M , and P_H ) were identified. At modifier concentrations up to P_M , the weakened hydrophobic environment resulted in polymer structural relaxation, which changed the recognition mechanisms. By contrast, at concentrations beyond P_H , considerably different enantioselectivity behaviors were observed, indicating that the existence of dipole-dipole interaction, which was stronger at higher modifier concentrations, contributed to the retention mechanisms. The concentrations at which these characteristic points occurred were dependent on the carbon number of the modifier molecule. Modifiers with more carbon numbers facilitated the transition in the enantioselective behaviors. These results demonstrated that the proposed method can provide a physically consistent quantitative description of enantioselective retention behavior in reversed-phase mode.

Recognition in the Domain of Molecular Chirality: From Noncovalent Interactions to Separation of Enantiomers

It is not a coincidence that both chirality and noncovalent interactions are ubiquitous in nature and synthetic molecular systems. Noncovalent interactivity between chiral molecules underlies enantioselective recognition as a fundamental phenomenon regulating life and human activities. Thus, noncovalent interactions represent the narrative thread of a fascinating story which goes across several disciplines of medical, chemical, physical, biological, and other natural sciences. This review has been conceived with the awareness that a modern attitude toward molecular chirality and its consequences needs to be founded on multidisciplinary approaches to disclose the molecular basis of essential enantioselective phenomena in the domain of chemical, physical, and life sciences. With the primary aim of discussing this topic in an integrated way, a comprehensive pool of rational and systematic multidisciplinary information is provided, which concerns the fundamentals of chirality, a description of noncovalent interactions, and their implications in enantioselective processes occurring in different contexts. A specific focus is devoted to enantioselection in chromatography and electromigration techniques because of their unique feature as "multistep" processes. A second motivation for writing this review is to make a clear statement about the state of the art, the tools we have at our disposal, and what is still missing to fully understand the mechanisms underlying enantioselective recognition.

Preparation of chiral stationary phase based on a [3+3] chiral polyimine macrocycle by thiol-ene click chemistry for enantioseparation in normal-phase and reversed-phase high performance liquid chromatography

Polyimine macrocycles are a new class of organic macrocycles with cyclic structures, well-defined molecular cavities, and multiple cooperative binding sites, which have recently aroused considerable research interest in molecular recognition and separation. Herein, we report the bonding of a [3+3] chiral polyimine macrocycle (H₃L, C₇₈H₇₈N₆O₃) on thiol-functionalized silica gel using thiol-ene click chemistry to prepare a chiral stationary phase (CSP) for high performance liquid chromatography (HPLC). The fabricated column exhibited excellent chiral separation capability under both normal-phase and reversed-phase conditions. Fourteen and 10 racemates were well resolved on the column in normal-phase mode (using n-hexane/isopropanol as the mobile phase) and reversed-phase mode (using methanol/water as the mobile phase), respectively, including alcohols, esters, ethers, ketones, aldehydes, epoxides and organic acids. Moreover, the column also shows good selectivity toward positional isomers. Six positional isomers (dinitrobenzene, chloroaniline, bromoaniline, iodoaniline, nitrobrobenzene and nitrochlorobenzene) were well separated on the column. In addition, the effects of the injection mass and mobile phase composition on the separation were investigated. The column shows good reproducibility and stability after multiple injections with the relative standard deviation (RSD) (n = 5) of the retention time and resolution being < 0.96 % and 0.65 %, respectively. This study indicates that this type of chiral polyimine macrocycles is a promising chiral selector for HPLC enantioseparation and will push forward the applications of more novel chiral macrocycles for chiral chromatographic separation.

Chiral stationary phases and applications in gas chromatography

Chiral compounds are ubiquitous in nature and play a pivotal role in biochemical processes, in chiroptical materials and applications, and as chiral drugs. The analysis and determination of the enantiomeric ratio (er) of chiral compounds is of enormous scientific, industrial, and economic importance. Chiral separation techniques and methods have become indispensable tools to separate chiral compounds into their enantiomers on an analytical as well on a preparative level to obtain enantiopure compounds. Chiral gas chromatography and high-performance liquid chromatography have paved the way and fostered several research areas, that is, asymmetric synthesis and catalysis in organic, medicinal, pharmaceutical, and supramolecular chemistry. The development of highly enantioselective chiral stationary phases was essential. In particular, the elucidation and understanding of the underlying enantioselective supramolecular separation mechanisms led to the design of new chiral stationary phases. This review article focuses on the development of chiral stationary phases for gas chromatography. The fundamental mechanisms of the recognition and separation of enantiomers and the selectors and chiral stationary phases used in chiral gas chromatography are presented. An overview over syntheses and applications of these chiral stationary phases is presented as a practical guidance for enantioselective separation of chiral compound classes and substances by gas chromatography.

Our research cooperation with Professor Yoshio Okamoto

This article summarizes our cooperation with the research group of Prof. Yoshio Okamoto at Nagoya University during the period of time between 1992 and 2005. Although the text deals entirely with enantioseparations in high-performance liquid chromatography, capillary electrophoresis, and capillary electrochromatography, this is not a detailed review in any of these areas. The text highlights selected aspects of these techniques, which have been the subject of our joint research and in part their reflection in follow-up research by our and other research groups. Together with more systematically studied topics, aspects such as ultrafast separation of enantiomers, uncommonly high separation factor of enantiomers and other related issues are also addressed.

Enantioseparation of 5,5'-Dibromo-2,2'-Dichloro-3-Selanyl-4,4'-Bipyridines on Polysaccharide-Based Chiral Stationary Phases: Exploring Chalcogen Bonds in Liquid-Phase Chromatography

The chalcogen bond (ChB) is a noncovalent interaction based on electrophilic features of regions of electron charge density depletion (σ-holes) located on bound atoms of group VI. The σ-holes of sulfur and heavy chalcogen atoms (Se, Te) (donors) can interact through their positive electrostatic potential (V) with nucleophilic partners such as lone pairs, π-clouds, and anions (acceptors). In the last few years, promising applications of ChBs in catalysis, crystal engineering, molecular biology, and supramolecular chemistry have been reported. Recently, we explored the high-performance liquid chromatography (HPLC) enantioseparation of fluorinated 3-arylthio-4,4′-bipyridines containing sulfur atoms as ChB donors. Following this study, herein we describe the comparative enantioseparation of three 5,5′-dibromo-2,2′-dichloro-3-selanyl-4,4′-bipyridines on polysaccharide-based chiral stationary phases (CSPs) aiming to understand function and potentialities of selenium σ-holes in the enantiodiscrimination process. The impact of the chalcogen substituent on enantioseparation was explored by using sulfur and non-chalcogen derivatives as reference substances for comparison. Our investigation also focused on the function of the perfluorinated aromatic ring as a π-hole donor recognition site. Thermodynamic quantities associated with the enantioseparation were derived from van’t Hoff plots and local electron charge density of specific molecular regions of the interacting partners were inspected in terms of calculated V. On this basis, by correlating theoretical data and experimental results, the participation of ChBs and π-hole bonds in the enantiodiscrimination process was reasonably confirmed.

Enantioseparation of Eight Pairs of Tetralone Derivative Enantiomers on Cellulose Based Chiral Stationary Phase by HPLC

Background:

Tetralone derivatives, important resources for the development of new drugs which can act in the treatment of central nervous system disorders or participate in synthesis reaction for the synthesis of various pharmaceuticals, have great research value and a bright prospect in exploitation.

Methods:

A novel chiral HPLC method for efficient enantioseparation of eight tetralone derivative enantiomers was developed on cellulose based CHIRALPAK IC chiral stationary phase under normal mode by investigating the effects of type and content of organic modifier, column temperature and flow rate on retention and enantioselectivity. Besides, the specificity, linearity, stability, precision, accuracy and robustness of this method were also validated.

Results:

Satisfactory enantioseparation was obtained for all enantiomers in n-hexane/2-propanol mobile phase system at ambient temperature. The thermodynamic study indicated that the solute transfer from the mobile to stationary phase was enthalpically favorable, and the process of enantioseparation was mainly enthalpy controlled. This method met the requirements for quantitative determination of tetralone derivative enantiomers.

Conclusion:

This study can provide great and important application value for enantioseparation of eight pairs of newly synthesized tetralone derivative enantiomers under normal mode using CHIRALPAK IC chiral column.

A study of tetrapeptide enantiomeric separation on crown ether based chiral stationary phases

The chiral separations of small peptides is an important challenge in the biological and medical sciences, because different stereoisomers of chiral drugs can often possess different pharmacological, pharmacokinetic, and/or toxicological activities. Commercially available crown ether chiral stationary phases based on S-(3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 (CROWNPAK CR-I (+)) and (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (ChiroSil RCA (+)) have been successfully used for separating enantiomers of various racemic compounds containing primary amino groups. In this investigation, enantioresolution of more complex model analyte - tetrapeptide Tyr-Arg-Phe-Lys-NH₂, has been reported on crown ether chiral stationary phases. Organic and acidic modifier content in aqueous mobile phase was tested. All Tyr-Arg-Phe-Lys-NH₂ stereoisomers showed U-shaped retention plots, based on ACN content in mobile phase. Increased retention of tetrapeptide stereoisomers was observed at low (<35%) and at high (>70%) acetonitrile content in the mobile phase, indicating that different separation mechanisms are most likely involved. As a result, baseline separation of all eight tetrapeptide enantiomer pairs was achieved under isocratic elution mode on both chiral columns.

Liquid chromatography separation of α- and γ-linolenic acid positional isomers with a stationary phase based on covalently immobilized cellulose tris(3,5-dichlorophenylcarbamate)

α-Linolenic acid (ALA) and its most important positional isomer γ-linolenic acid (GLA), are essential fatty acids (vitamin F). Therefore, ALA- and GLA-rich edible oils hold great potential in human and animal nutrition, as well as in nutraceutics and cosmetics. Quality control and nutritional validation of oil products is thus of increasing importance. In the present study, the cellulose tris(3,5-dichlorophenylcarbamate)-based chiral stationary phase was successfully used for separation of ALA and GLA, a major challenge in the liquid chromatography of these isomers. The chromatographic conditions were firstly optimized on a HPLC system with UV detection, and the use of a reversed-phase eluent system made up of aqueous 10 mM ammonium acetate/acetonitrile (40/60, v/v; _w^spH6.0) with a 25 °C column temperature resulted optimal for the simultaneous discrimination of the two isomers at a 0.5 mL/min flow rate (α = 1.10; R_S = 1.21). The method was then optimized for LC-MS/MS implementation. The proposed innovative separation method holds a great potential for the quantification of ALA and GLA in food and biological matrices, thus opening the way to further investigations involving the two positional isomers.

Comparative study on enantiomer resolving ability of amylose tris(3-chloro-5-methylphenylcarbamate) covalently immobilized onto silica in nano-liquid chromatography and capillary electrochromatography

In the present study separation of enantiomers of some chiral neutral and weakly acidic analytes was investigated on the chiral stationary phase (CSP) made by covalent immobilization of amylose tris(3-chloro-5-methylphenylcarbamate) onto silica in nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) in acetonitrile and aqueous acetonitrile. Few comparisons were made also between the enantioseparations in nano-LC and high-performance liquid chromatography (HPLC) with the chiral column of 4.6 × 250 mm dimension. Slightly better separation of enantiomers was observed in HPLC mode compared to nano-LC mode. It was shown that in the capillary columns packed with the CSP containing about 20% (w/w) of a covalently immobilized neutral chiral selector, amylose tris(3-chloro-5-methylphenylcarbamate), sufficient electroosmotic flow has been generated and enantioseparations with reasonable analysis time were performed also in CEC mode. It was shown once again that CEC offers a clear advantage over nano-LC from the viewpoint of plate numbers and peak resolution.

Hybrid Organic-Inorganic Materials Containing a Nanocellulose Derivative as Chiral Selector

Hybrid organic-inorganic materials (HOIM), with high mechanical stability, large surface area, tailored pore size, controlled morphology, and organic loading have shown superior chiral separation performance. In this chapter, the preparation of hybrid organic-inorganic materials of core-shell silica microspheres by a layer-by-layer self-assembly method is described. The enantioseparation performance by high-performance liquid chromatography is illustrated by various types of chiral compounds under normal- and reversed-phase elution conditions. The chiral selector of nanocrystalline cellulose derivative hybrid organic-inorganic materials showed good performance in the separation of enantiomers.

HPLC Enantioseparations with Polysaccharide-Based Chiral Stationary Phases in HILIC Conditions

In contrast to achiral hydrophilic interaction liquid chromatography (HILIC), which is a popular and largely applied technique to analyze polar compounds such as pharmaceuticals, metabolites, proteins, peptides, amino acids, oligonucleotides, and carbohydrates, the introduction of the HILIC concept in enantioselective chromatography has been relatively recent and scarcely debated. In this chapter, the HILIC enantioseparations carried out on polysaccharide-based chiral stationary phases are grouped and discussed. Another objective of this chapter is to provide a comprehensive overview and insight into the experimental conditions needed to operate under HILIC mode. Finally, to stimulate and facilitate the application of this chromatographic technique, a detailed experimental protocol of a chiral resolution on a chlorinated cellulose-based chiral stationary phase under HILIC conditions is described.

Polysaccharide-Based Chiral Stationary Phases for Enantioseparations by High-Performance Liquid Chromatography: An Overview

This chapter summarizes the application of polysaccharide-based chiral stationary phases (CSPs) for separation of enantiomers in high-performance liquid chromatography (HPLC). Since this book contains dedicated chapters on enantioseparations using supercritical fluid chromatography (SFC), or capillary electrochromatography (CEC), the application of polysaccharide-based materials in these modes of liquid-phase separation techniques is touched just superficially. Special emphasis is directed toward a discussion of the optimization of polysaccharide-based chiral selectors, their attachment onto the carrier, and the optimization of the support. The optimization of the separation of enantiomers based on various parameters such as mobile phase composition and temperature is discussed.

A chromatographic study on the retention behavior of the amylose tris(3-chloro-5-methylphenylcarbamate) chiral stationary phase under aqueous conditions

In this study, the retention properties of the immobilized polysaccharide-derived Chiralpak IG-3 chiral stationary phase under aqueous-organic conditions were investigated. A systematic evaluation of the retention factors of the enantiomers of the chiral sulfoxide oxfendazole, endowed with anthelmintic activity and selected as test compound, was carried out changing progressively the water content in hydro-organic eluents containing methanol, ethanol or acetonitrile. From the results obtained with acetonitrile/water mobile phases and the associated retention plots, clear U-shape retention dependencies, indicative of the interplay of both hydrophilic interaction liquid chromatography and reversed-phase modes, were highlighted. A U-turn point of retention mechanism was recorded in correspondence of the acetonitrile/water 100:40 v/v mobile phase. Retention was significantly affected by small percentages of trifluoroacetic acid or diethylamine additives incorporated in the mobile phase. It is worth emphasizing that the basic additive was more effective in reducing retention in the reversed-phase region, while the action of acid additive was more pronounced in the hydrophilic interaction liquid chromatography region. Finally, either in the transition from hydrophilic interaction liquid chromatography to reversed-phase conditions or after additive addition, the enantioselectivity did not vary significantly.

Macrocyclic glycopeptide chiral selectors bonded to core-shell particles enables enantiopurity analysis of the entire verubecestat synthetic route

Verubecestat is an inhibitor of β-site amyloid precursor protein cleaving enzyme 1 (BACE1) being evaluated in clinical trials for the treatment of Alzheimer's disease. Synthetic route development involves diastereoselective transformations with a need for enantiomeric excess (ee) determination of each intermediate and final active pharmaceutical ingredient (API). The analytical technical package of validated methods relies on enantioselective SFC and RPLC separations using multiple 3 and 5 μm coated polysaccharide-based chiral stationary phases (CSPs) and mobile phases combinations. Evaluation of recently developed chiral columns revealed a single chiral selector (Teicoplanin) bonded to 2.7 μm core-shell particles using H₃PO₄ in H₂O/ACN and triethylammonium acetate: methanol based eluents at different isocratic compositions allowed good enatioseparation of all verubecestat intermediates. EE determination of verubecestat is easily performed on NicoShell, another macrocyclic glycopeptide chiral selector bonded to 2.7 μm superficially porous particles. This approach enables fast and reliable enantiopurity analysis of the entire verubecestat synthetic route using only two chiral columns and mobile phases on a conventional HPLC system, simplifying technical package preparation, method validation and transfer to manufacturing facilities.

Enantioseparation of novel chiral sulfoxides on chlorinated polysaccharide stationary phases in supercritical fluid chromatography

Asymmetric sulfoxides is a particular case of chirality that may be found in natural as well as synthetic products. Twenty-four original molecules containing a sulfur atom as a centre of chirality were analyzed in supercritical fluid chromatography on seven polysaccharide-based chiral stationary phases (CSP) with carbon dioxide - methanol mobile phases. While all the tested CSP provided enantioseparation for a large part of the racemates, chlorinated cellulosic phases proved to be both highly retentive and highly enantioselective towards these species. Favourable structural features were determined by careful comparison of the enantioseparation of the probe molecules. Molecular modelling studies indicate that U-shaped (folded) conformations were most favorable to achieve high enantioresolution on these CSP, while linear (extended) conformations were not so clearly discriminated. For a subset of these species adopting different conformations, a broad range of mobile phase compositions, ranging from 20 to 100% methanol in carbon dioxide, were investigated. While retention decreased continuously in this range, enantioseparation varied in a non-monotonous fashion. Abrupt changes in the tendency curves of retention and selectivity were observed when methanol proportion reaches about 60%, suggesting that a change in the conformation of the analytes and/or chiral selector is occurring at this point.

Structural dependence on the property of chiral stationary phases derived from chitosan bis(arylcarbamate)-(amide)s

The goal of present study was to investigate the structural dependence of chitosan derivatives on enantioseparation and mobile phase tolerance of the corresponding chiral packing materials for liquid chromatography. Hence, a series of chitosan bis(arylcarbamate)-(n-pentyl amide)s and the related chiral stationary phases (CSPs) were prepared from chitosans with different molecular weights. Because of the H-bond formed via CH₃-π interaction, the CSP bearing methyl substituent exhibited high tolerance than the ones bearing dichloro substituents. The CSP derived from the chitosan bis(3,5-dichlorophenylcarbamate)-(n-pentyl amide) with a higher molecular weight possessed high tolerance to mobile phases, whereas the enantioseparation capability of this CSP was not as good as that of the one prepared from the chitosan derivative with a lower molecular weight. Therefore, enantioseparation capability and mobile phase tolerance have to be counterbalanced in designing chiral selectors for the CSPs derived from chitosan bis(arylcarbamate)-(amide)s.

Effect of pore-size optimization on the performance of polysaccharide-based superficially porous chiral stationary phases for the separation of enantiomers in high-performance liquid chromatography

Our earlier studies on the preparation of chiral stationary phases (CSP) based on superficially porous (or core-shell) silica (SPS) particles for the separation of enantiomers in HPLC have provided proof to the advantages of such sorbents. In particular, higher enantioselectivity was observed with the columns packed with superficially porous CSP compared to the columns packed with fully-porous (FP) silica-based CSPs at comparable content of chiral selector (polysaccharide derivative) in CSP. Also, less dependence of plate height on mobile phase flow rate and higher plate numbers and resolution calculated per unit time (i.e. speed of separation) were observed with SPS-based CSPs. Thirty years of CSP development have demonstrated that wide-pore silica has to be used as a support for large molecular weight chiral selectors such as the ones based on polysaccharides. In this study the effect of pore size of the core-shell silica support and of other experimental factors on column performance is demonstrated. Reduced plate heights in the range 1.4-1.5 were obtained, as well as highly effective baseline separations of enantiomers were observed with analysis times of less than 15s.

Facile Diastereoseparation of Glycosyl Sulfoxides by Chiral Stationary Phase

Separation of the diastereomers of glycosyl sulfoxides differing in the sulfur chirality has been difficult. This article presents a fast and scalable method for their diastereoseparation using a chiral stationary phase. The usefulness of this method was demonstrated in a 500-mg scale separation within 20 min, and in the separation of trisaccharyl sulfoxide diastereomers. Chirality 28:534-539, 2016. © 2016 Wiley Periodicals, Inc.