Soluble thiabendazolium salts with anthelminthic properties

Thiabendazole is an anthelmintic drug used to treat strongyloidiasis (threadworm), cutaneous and visceral larva migrans, trichinosis, and other parasites. The active pharmaceutical ingredient is typically administered orally as tablets that should be chewed before swallowing. Current formulations combine the active ingredient with excipients, including sodium saccharinate as a sweetener. Thiabendazole's low aqueous solubility hinders fast dissolution and absorption through the mucous membranes. We sought to reformulate this medicine to improve both solubility and palatability. We utilized the possibility of protonation of the azole nitrogen atom and selected four different hydrogen donors: saccharin, fumaric, maleic, and oxalic acids. Solvothermal synthesis resulted in salts with each co-former, whereas neat and liquid-assisted grinding enabled the synthesis of additional formulations. Product formation was observed by powder X-ray diffraction. To better understand the structural basis of the proton transfer, we solved the crystal structures of the salts with saccharin, maleic acid, and oxalic acid using single-crystal X-ray diffraction. The structure of the salt with fumaric acid was solved by powder X-ray diffraction. We further characterized the salts with vibrational spectroscopic and thermoanalytical methods. We report a broad tunability of the aqueous solubility of thiabendazole by salt formation. Reformulation with maleic acid provided a 60-fold increase in solubility, while saccharin and oxalic acid gave a modest improvement. Fumaric acid resulted in a solid with only slightly higher solubility. Furthermore, saccharin is a sweetener, while the acids taste sour. Therefore, the salts formed also result in an intrinsic improvement of palatability. These results can inform new strategies for oral and chewable tablet formulations for treating helminthic infections.

Structural Basis of Saccharin Derivative Inhibition of Carbonic Anhydrase IX

This study explores the binding mechanisms of saccharin derivatives with human carbonic anhydrase IX (hCA IX), an antitumor drug target, with the aim of facilitating the design of potent and selective inhibitors. Through the use of crystallographic analysis, we investigate the structures of hCA IX-saccharin derivative complexes, unveiling their unique binding modes that exhibit both similarities to sulfonamides and distinct orientations of the ligand tail. Our comprehensive structural insights provide information regarding the crucial interactions between the ligands and the protein, shedding light on interactions that dictate inhibitor binding and selectivity. Through a comparative analysis of the binding modes observed in hCA II and hCA IX, isoform-specific interactions are identified, offering promising strategies for the development of isoform-selective inhibitors that specifically target tumor-associated hCA IX. The findings of this study significantly deepen our understanding of the binding mechanisms of hCA inhibitors, laying a solid foundation for the rational design of more effective inhibitors.

Effect of artificial sweetener saccharin on lysozyme aggregation: A combined spectroscopic and in silico approach

The use of saccharin in food products attracts much attention as it involves the risk of lethal allergies and many protein aggregation diseases. However, its role in protein aggregation has not been explored to date. This study embodies the effect of artificial sweeteners on HEWL in the absence and presence of commonly available natural products such as curcumin and EGCG. Various techniques have been used to characterize the protein interaction, such as steady-state emission and time-resolved fluorescence, FTIR, gel electrophoresis, TEM, and molecular docking. Steady-state and time-resolved studies revealed the binding strength and concomitant effect of saccharin on HEWL protein. Kinetic measurements revealed that saccharin causes significant enhancement of HEWL aggregation with a considerable reduction in lag phase time i.e. from 37 hr to 08 hr. Whereas in the presence of natural products, the effect of saccharin on HEWL aggregation was significantly reduced specifically in the case of curcumin. The result obtained in the fluorescence experiment were also supported by the gel electrophoresis technique and morphological images taken by TEM. The rapid change in the secondary structure of the protein in the presence of saccharin was confirmed by the FTIR spectroscopy technique. This study is instrumental in understanding the effect of saccharin on protein aggregation and the role of commonly available natural products in curbing its effect.

Effect of Coformer Selection on In Vitro and In Vivo Performance of Adefovir Dipivoxil Cocrystals

PURPOSE

This study aimed to improve the in vitro dissolution, permeability and oral bioavailability of adefovir dipivoxil (ADD) by cocrystal technology and clarify the important role of coformer selection on the cocrystal's properties.

METHODS

ADD was cocrystallized with three small molecules (i.e., paracetamol (PA), saccharin (SAC) and nicotinamide (NIC)), respectively. The obtained ADD-PA cocrystal was characterized by DSC, TGA, PXRD and FTIR. Comparative study on dissolution rates among the three ADD cocrystals were conducted in water and pH 6.8 phosphate buffer. Besides, effects of coformers on intestinal permeability of ADD were evaluated via in vitro Caco-2 cell model and in situ single-pass intestinal perfusion model in rats. Furthermore, in vivo pharmacokinetic study of ADD cocrystals was also compared.

RESULTS

Dissolution rates of ADD cocrystals were improved with the order of ADD-SAC cocrystal > ADD-PA cocrystal > ADD-NIC cocrystal. The permeability studies on Caco-2 cell model and single-pass intestinal perfusion model indicated that PA could enhance intestinal absorption of ADD by P-gp inhibition, while SAC and NIC did not. Further in vivo pharmacokinetic study showed that ADD-SAC cocrystal exhibited higher C_max (1.4-fold) and AUC_0-t (1.3-fold) of ADD than administration of ADD alone, and C_max and AUC_0-t of ADD-PA cocrystal were significantly enhanced by 2.1-fold and 2.2-fold, respectively, which was attributed to its higher dissolution and improved intestinal permeability.

CONCLUSION

Coformer selection had an important role on cocrystal's properties, and cocrystallization of ADD with a suitable coformer was an effective approach to enhance both dissolution and bioavailability of ADD.

Terahertz spectroscopic characterizations and DFT calculations of carbamazepine cocrystals with nicotinamide, saccharin and fumaric acid

Carbamazepine cocrystals with nicotinamide, saccharin and fumaric acid were synthesized and characterized by time-domain terahertz spectroscopy. Lattice vibrations of cocrystals with their individual constituents were investigated by means of the dispersion-corrected density functional theory with and without cell parameter constraints. The simulated THz spectra successfully reproduce the features of all the crystals in their experimental spectra. A better agreement between experimental and theoretical THz spectra is achieved when the cell parameter constraints are applied in geometry optimization. Some intensive modes of neat carbamazepine and cocrystals were discussed in terms of the motions of hydrogen bonds. The effect of lattice vibration on these cocrystallizations was further examined to gain insights into the thermodynamics. It is found that lattice vibration is favorable for all these cocrystal formations.

Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate aza-heterocycle directing groups that are useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated by the facile reactivity of the β-γ alkene of the starting material, whereas the ϵ-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of an analogous method with alkyne substrates. Mechanistic studies reveal the importance of the dissociation of the weakly coordinating directing group to allow the allyl moiety to bind and facilitate C(sp3 )-C(sp3 ) reductive elimination.

Cocrystal Solubility Advantage Diagrams as a Means to Control Dissolution, Supersaturation, and Precipitation

Cocrystals are often more soluble than needed and pose unnecessary risks for precipitation of less soluble forms of the drug during processing and dissolution. Such conversions lead to erratic cocrystal behavior and nullify the cocrystal solubility advantage over parent drug (SA = Scocrystal/Sdrug). This work demonstrates a quantitative method for additive selection to control cocrystal disproportionation based on cocrystal solubility advantage (SA) diagrams. The tunability of cocrystal SA is dependent on the selective drug-solubilizing power of surfactants (SPdrug = (ST/Saq)drug). This cocrystal property is used to generate SA-SP diagrams that facilitate surfactant selection and provide a framework for evaluating how SA influences drug concentration-time profiles associated with cocrystal dissolution, drug supersaturation, and precipitation (DSP). Experimental results with indomethacin-saccharin cocrystal and surfactants (sodium lauryl sulfate, Brij, and Myrj) demonstrate the log-linear relationship characteristic of SA-SP diagrams and the dependence of σmax and dissolution area under the curve (AUC) on SA with characteristic maxima at a threshold supersaturation where drug nucleation occurs. This approach is expected to streamline cocrystal formulation as it facilitates additive selection by considering the interplay between thermodynamic (SA) and kinetic (DSP) processes.

DSC, FTIR and Raman Spectroscopy Coupled with Multivariate Analysis in a Study of Co-Crystals of Pharmaceutical Interest

Co-crystals have garnered increasing interest in recent years as a beneficial approach to improving the solubility of poorly water soluble active pharmaceutical ingredients (APIs). However, their preparation is a challenge that requires a simple approach towards co-crystal detection. The objective of this work was, therefore, to verify to what extent a multivariate statistical approach such as principal component analysis (PCA) and cluster analysis (CA) can be used as a supporting tool for detecting co-crystal formation. As model samples, physical mixtures and co-crystals of indomethacin with saccharin and furosemide with p-aminobenzoic acid were prepared at API/co-former molar ratios 1:1, 2:1 and 1:2. Data acquired from DSC curves and FTIR and Raman spectroscopies were used for CA and PCA calculations. The results obtained revealed that the application of physical mixtures as reference samples allows a deeper insight into co-crystallization than is possible with the use of API and co-former or API and co-former with physical mixtures. Thus, multivariate matrix for PCA and CA calculations consisting of physical mixtures and potential co-crystals could be considered as the most profitable and reliable way to reflect changes in samples after co-crystallization. Moreover, complementary interpretation of results obtained using DSC, FTIR and Raman techniques is most beneficial.

Understanding the Differences Between Cocrystal and Salt Aqueous Solubilities

This work challenges the popular notion that pharmaceutical salts are more soluble than cocrystals. There are cocrystals that are more soluble than salt forms of a drug and vice-versa. It all depends on the interplay between the chemistry of both the solid and solution phases. Aqueous solubility, pHmax, and supersaturation index (SA = SCC/SD or Ssalt/SD) of cocrystals and salts of a basic drug, lamotrigine (LTG), were determined, and mathematical models that predict the influence of cocrystal/salt Ksp and Ka were derived. Ksp and SA followed the order LTG-nicotinamide cocrystal (18) > LTG-HCl salt (12) > LTG-saccharin salt (5) > LTG-methylparaben cocrystal (1) > LTG-phenobarbital cocrystal (0.2). The values in parenthesis represent SA under nonionizing conditions. Cocrystal/salt solubility and thermodynamic stability are determined by pH and will drastically change with a single unit change in pH. pHmax values ranged from 5.0 (saccharin salt) to 6.4 (methylparaben cocrystal) to 9.0 (phenobarbital cocrystal). Cocrystal/salt pHmax dependence on pKsp and pKa shows that cocrystals and salts exhibit different behavior. Solubility and pHmax are as important as supersaturation index in assessing the stability and risks associated with conversions of supersaturating forms.

Synthesis, antimicrobial, DNA cleavage and antioxidant activities of tricyclic sultams derived from saccharin

Two series of fused tricyclic sultams (carboxylates, 3a, b and 5a, f, g and anilides 5b-e) were synthesized from saccharin and their chemical structures were confirmed by spectroscopic tools. Then, their antibacterial activities and MIC were evaluated against two strains of gram positive and gram-negative bacteria. The MIC values of the tested compounds are in the of range 8-33 μg/ml. In addition, their DNA cleavage ability, binding affinity and their anticancer activities against hepatic cancer cell were tested. And their antioxidant activities were also measured. Four carboxylate derivatives (3a, 5a, 5f and 5g) and one anilide (5d) of the tested compounds proved to be the highest activity all over the study.

Thermodynamic Investigation of Carbamazepine-Saccharin Co-Crystal Polymorphs

Polymorphism in active pharmaceutical ingredients can be regarded as critical for the potential that crystal form can have on the quality, efficacy, and safety of the final drug product. The current contribution aims to characterize thermodynamic interrelationship of a dimorphic co-crystal, FI and FII, involving carbamazepine (CBZ) and saccharin (SAC) molecules. Supramolecular synthesis of CBZ-SAC FI and FII has been performed using thermokinetic methods and systematically characterized by differential scanning calorimetry, powder X-ray diffraction, solubility, and slurry measurements. According to the heat of fusion rule by Burger and Ramberger, FI (ΔH_fus = 121.1 J/g; melting point, 172.5°C) and FII (ΔH_fus = 110.3 J/g; melting point, 164.7°C) are monotropically related. The solubility and van't Hoff plot results suggest FI stable and FII metastable forms. This study reveals that CBZ-SAC co-crystal phases, FI or FII, could be stable to heat-induced stresses; however, FII converts to FI during solution-mediated transformation.

Removal and attenuation of sewage effluent combined tracer signals of phosphorus, caffeine and saccharin in soil

Contaminants in septic tank effluent (STE) are expected to be removed by the soil system before discharging to the environment. However, potential contaminants such as phosphorus (P), caffeine and artificial sweeteners do find their way to watercourses impacting aquatic eco systems. In this study, the attenuation of STE P, caffeine and saccharin were investigated in untreated soil and in soil with reduced microbial activity, in aqueous solutions and in the complex matrix of STE. Time series sorption and desorption experiments using batch equilibrium and a column experiment of STE P attenuation were conducted. The results revealed that the soil distribution coefficients (K_d) were: P 81.57 > caffeine 22.16 > saccharin 5.98 cm³/g, suggesting greater soil affinity to P adsorption. The data revealed that 80% of saccharin and 33% of caffeine attenuation was associated with microbial activities rather than adsorption processes. However, a complete removal of saccharin and caffeine did not occur during the equilibration period, suggesting their leaching potential. The dominant mechanism of P attenuation was adsorption (chemical and physical), yielding P retention of >73% and 35% for P in aqueous solution and in STE matrix, respectively, for batch equilibrium. The soil in the column acted as effluent P sink retaining 125 μg P/g soil of effluent P. The attenuation of P, caffeine and saccharin in the aqueous solution was greater than in STE, suggesting that the complex composition of STE reduced soil adsorption ability, and that other substances present in STE may be competing for soil binding sites. The data revealed that caffeine and P had similarities in the interaction with soils and thus caffeine may be considered as a STE tracer of anthropogenic source of P in receiving waters.

Degradation of artificial sweeteners via direct and indirect photochemical reactions

We studied the direct and indirect photochemical reactivity of artificial sweeteners acesulfame, saccharin, cyclamic acid and sucralose in environm entally relevant dilute aqueous solutions. Aqueous solutions of sweeteners were irradiated with simulated solar radiation (>290 nm; 96 and 168 h) or ultraviolet radiation (UVR; up to 24 h) for assessing photochemical reactions in surface waters or in water treatment, respectively. The sweeteners were dissolved in deionised water for examination of direct photochemical reactions. Direct photochemical reactions degraded all sweeteners under UVR but only acesulfame under simulated solar radiation. Acesulfame was degraded over three orders of magnitude faster than the other sweeteners. For examining indirect photochemical reactions, the sweeteners were dissolved in surface waters with indigenous dissolved organic matter or irradiated with aqueous solutions of nitrate (1 mg N/L) and ferric iron (2.8 mg Fe/L) introduced as sensitizers. Iron enhanced the photodegradation rates but nitrate and dissolved organic matter did not. UVR transformed acesulfame into at least three products: iso-acesulfame, hydroxylated acesulfame and hydroxypropanyl sulfate. Photolytic half-life was one year for acesulfame and more than several years for the other sweeteners in surface waters under solar radiation. Our study shows that the photochemical reactivity of commonly used artificial sweeteners is variable: acesulfame may be sensitive to photodegradation in surface waters, while saccharin, cyclamic acid and sucralose degrade very slowly even under the energetic UVR commonly used in water treatment.

Small-Scale Assays for Studying Dissolution of Pharmaceutical Cocrystals for Oral Administration

The purpose of this study was to better understand the dissolution properties and precipitation behavior of pharmaceutical cocrystals of poorly soluble drugs for the potential for oral administration based on a small-scale dissolution assay. Carbamazepine and indomethacin cocrystals with saccharin and nicotinamide as coformers were prepared with the sonic slurry method. Dissolution of the poorly soluble drugs indomethacin and carbamazepine and their cocrystals was studied with a small-scale dissolution assay installed on a SiriusT3 instrument. Two methodologies were used: (i) surface dissolution of pressed tablet (3 mm) in 20 mL running for fixed times at four pH stages (pH 1.8, pH 3.9, pH 5.4, pH 7.3) and (ii) powder dissolution (2.6 mg) in 2 mL at a constant pH (pH 2). Improved dissolution and useful insights into precipitation kinetics of poorly soluble compounds from the cocrystal form can be revealed by the small-scale dissolution assay. A clear difference in dissolution/precipitation behaviour can be observed based on the characteristics of the coformer used.

Degradation of artificial sweetener saccharin in aqueous medium by electrochemically generated hydroxyl radicals

The removal of artificial sweetener saccharin (SAC) in aqueous solution by electrochemical advanced oxidation using electro-Fenton process was performed. Experiments were carried out in an undivided cylindrical glass cell with a carbon-felt cathode and a Pt or boron-doped diamond (BDD) anode. The removal of SAC by electrochemically generated hydroxyl radicals followed pseudo-first-order kinetics with both Pt and BDD anode. The absolute rate constant of the SAC hydroxylation reaction was determined for the first time using the competition kinetic method and found to be (1.85 ± 0.01) × 10(9) M(-1) s(-1). The comparative study of TOC removal efficiency during electro-Fenton treatment indicated a higher mineralization rate with BDD than Pt anode. The identification and evolution of short-chain carboxylic acids and inorganic ions formed during oxidation process were monitored by ion-exchange chromatography and ion chromatography, respectively. The assessment of toxicity of SAC and/or its reaction by-products during treatment was performed using Microtox® method based on the Vibrio fischeri bacteria luminescence inhibition. Results showed that the process was able to efficiently detoxify the treated solution.

Sorption and biodegradation of artificial sweeteners in activated sludge processes

There is limited information on the occurrence and removal of artificial sweeteners (ASs) in biological wastewater treatment plants, and in particular, the contribution of sorption and biodegradation to their removal. This study investigated the fate of ASs in both the aqueous and solid phases in a water reclamation plant (WRP). All the four targeted ASs, i.e. acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharine (SAC), were detected in both the aqueous and solid phases of raw influent and primary effluent samples. The concentrations of CYC and SAC in secondary effluent or MBR permeate were below their method detection limits. ACE and SUC were persistent throughout the WRP, whereas CYC and SAC were completely removed in biological treatment (>99%). Experimental results showed that sorption played a minor role in the elimination of the ASs due to the relatively low sorption coefficients (Kd), where Kd<500L/kg. In particular, the poor removal of ACE and SUC in the WRP may be attributed to their physiochemical properties (i.e. logKow<0 or logD<3.2) and chemical structures containing strong withdrawing electron functional groups in heterocyclic rings (i.e. chloride and sulfonate).

A General Approach to Sequence-Controlled Polymers Using Macrocyclic Ring Opening Metathesis Polymerization

A new and general strategy for the synthesis of sequence-defined polymers is described that employs relay metathesis to promote the ring opening polymerization of unstrained macrocyclic structures. Central to this approach is the development of a small molecule "polymerization trigger" which when coupled with a diverse range of sequence-defined units allows for the controlled, directional synthesis of sequence controlled polymers.

Null mutation of 5α-reductase type I gene alters ethanol consumption patterns in a sex-dependent manner

The neuroactive steroid allopregnanolone (ALLO) is a positive modulator of GABAA receptors, and manipulation of neuroactive steroid levels via injection of ALLO or the 5α-reductase inhibitor finasteride alters ethanol self-administration patterns in male, but not female, mice. The Srd5a1 gene encodes the enzyme 5α-reductase-1, which is required for the synthesis of ALLO. The current studies investigated the influence of Srd5a1 deletion on voluntary ethanol consumption in male and female wildtype (WT) and knockout (KO) mice. Under a continuous access condition, 6 and 10 % ethanol intake was significantly greater in KO versus WT females, but significantly lower in KO versus WT males. In 2-h limited access sessions, Srd5a1 deletion retarded acquisition of 10 % ethanol intake in female mice, but facilitated it in males, versus respective WT mice. The present findings demonstrate that the Srd5a1 gene modulates ethanol consumption in a sex-dependent manner that is also contingent upon ethanol access condition and concentration.

Anticancer effect of a novel palladium-saccharinate complex of terpyridine by inducing apoptosis on Ehrlich ascites carcinoma (EAC) in Balb-C mice

BACKGROUND/AIM

[Pd(sac)(terpy)](sac)•4H2O (sac=saccharinate and terpy=2,2':6',2"-terpyridine) is newly-synthesized palladium(II) (Pd) complex. We investigated the antiproliferative and apoptotic effects of this complex on Ehrlich ascites carcinoma (EAC).

MATERIALS AND METHODS

EAC cells were administered to 33 Balb/c mice. Mice were divided randomly into four groups: control, cisplatin, Pd(II) complex and paclitaxel. Control group animals received 0.9% NaCl; other groups received treatments cisplatin, Pd(II) complex and paclitaxel on days 7 and 12. At day 14, animals were sacrificed. Expression of active caspase-3, p53 and proliferating cell nuclear antigen (PCNA) was investigated and apoptosis was evaluated by terminal deoxynucleotidyltransferase (TdT)-mediated nick-end labelling (TUNEL) technique.

RESULTS

Expression of p53 and PCNA were found to be decreased (p<0.0001), cells with active caspase-3 and TUNEL-positive cells were found to be increased (p<0.0001) in all treatment groups.

CONCLUSION

Like cisplatin and paclitaxel, this Pd(II) complex has a strong anticancer activity against EAC by inducing apoptosis and suppressing proliferation in vivo.

Saccharin: a lead compound for structure-based drug design of carbonic anhydrase IX inhibitors

Carbonic anhydrase IX (CA IX) is a key modulator of aggressive tumor behavior and a prognostic marker and target for several cancers. Saccharin (SAC) based compounds may provide an avenue to overcome CA isoform specificity, as they display both nanomolar affinity and preferential binding, for CA IX compared to CA II (>50-fold for SAC and >1000-fold when SAC is conjugated to a carbohydrate moiety). The X-ray crystal structures of SAC and a SAC-carbohydrate conjugate bound to a CA IX-mimic are presented and compared to CA II. The structures provide substantial new insight into the mechanism of SAC selective CA isoform inhibition.

Fate of artificial sweeteners in wastewater treatment plants in New York State, U.S.A

Very few studies describe the fate of artificial sweeteners (ASWs) in wastewater treatment plants (WWTPs). In this study, mass loadings, removal efficiencies, and environmental emission of sucralose, saccharin, aspartame, and acesulfame were determined based on the concentrations measured in wastewater influent, primary effluent, effluent, suspended particulate matter (SPM), and sludge collected from two WWTPs in the Albany area of New York State, U.S.A. All ASWs were detected at a mean concentration that ranged from 0.13 (aspartame) to 29.4 μg/L (sucralose) in wastewater influent, 0.49 (aspartame) to 27.7 μg/L (sucralose) in primary influent, 0.11 (aspartame) to 29.6 μg/L (sucralose) in effluent, and from 0.08 (aspartame) to 0.65 μg/g dw (sucralose) in sludge. Aspartame was found in 92% of influent SPM samples at a mean concentration of 444 ng/g dw, followed by acesulfame (92 ng/g) and saccharin (49 ng/g). The fraction of the total mass of ASWs sorbed to SPM was in the rank order: aspartame (50.4%) > acesulfame (10.9%) > saccharin and sucralose (0.8%). The sorption coefficients of ASWs ranged from 4.10 (saccharin) to 4540 L/kg (aspartame). Significant removal of aspartame (68.2%) and saccharin (90.3%) was found in WWTPs; however, sucralose and acesulfame were less efficiently removed (<2.0%). The total mass loading of sucralose, saccharin, and acesulfame in the WWTP that served a smaller population (∼15,000) was 1.3-1.5 times lower than that in another WWTP that served a larger population (∼100,000). The average daily loading of sucralose in both WWTPs (18.5 g/d/1000 people) was ∼2 times higher than the average loading of saccharin. The daily discharge of sucralose from the WWTPs was the highest (17.6 g/d/1000 people), followed by acesulfame (1.22 g/d/1000 people), and saccharin (1.07 g/d/1000 people). Approximately, 1180 g of saccharin and 291 g of acesulfame were transformed in or removed daily from the two WWTPs. This is the first study to describe the fate of ASWs, including the fraction found in SPM and in sludge, in addition to the aqueous portion of wastewater in WWTPs.

Diverse signaling systems activated by the sweet taste receptor in human GLP-1-secreting cells

Sweet taste receptor regulates GLP-1 secretion in enteroendocrine L-cells. We investigated the signaling system activated by this receptor using Hutu-80 cells. We stimulated them with sucralose, saccharin, acesulfame K and glycyrrhizin. These sweeteners stimulated GLP-1 secretion, which was attenuated by lactisole. All these sweeteners elevated cytoplasmic cyclic AMP ([cAMP]c) whereas only sucralose and saccharin induced a monophasic increase in cytoplasmic Ca(2+) ([Ca(2+)]c). Removal of extracellular calcium or sodium and addition of a Gq/11 inhibitor greatly reduced the [Ca(2+)]c responses to two sweeteners. In contrast, acesulfame K induced rapid and sustained reduction of [Ca(2+)]c. In addition, glycyrrhizin first reduced [Ca(2+)]c which was followed by an elevation of [Ca(2+)]c. Reductions of [Ca(2+)]c induced by acesulfame K and glycyrrhizin were attenuated by a calmodulin inhibitor or by knockdown of the plasma membrane calcium pump. These results indicate that various sweet molecules act as biased agonists and evoke strikingly different patterns of intracellular signals.

Administration of saccharin to neonatal mice influences body composition of adult males and reduces body weight of females

Nutritional or pharmacological perturbations during perinatal growth can cause persistent effects on the function of white adipose tissue, altering susceptibility to obesity later in life. Previous studies have established that saccharin, a nonnutritive sweetener, inhibits lipolysis in mature adipocytes and stimulates adipogenesis. Thus, the current study tested whether neonatal exposure to saccharin via maternal lactation increased susceptibility of mice to diet-induced obesity. Saccharin decreased body weight of female mice beginning postnatal week 3. Decreased liver weights on week 14 corroborated this diminished body weight. Initially, saccharin also reduced male mouse body weight. By week 5, weights transiently rebounded above controls, and by week 14, male body weights did not differ. Body composition analysis revealed that saccharin increased lean and decreased fat mass of male mice, the latter due to decreased adipocyte size and epididymal, perirenal, and sc adipose weights. A mild improvement in glucose tolerance without a change in insulin sensitivity or secretion aligned with this leaner phenotype. Interestingly, microcomputed tomography analysis indicated that saccharin also increased cortical and trabecular bone mass of male mice and modified cortical bone alone in female mice. A modest increase in circulating testosterone may contribute to the leaner phenotype in male mice. Accordingly, the current study established a developmental period in which saccharin at high concentrations reduces adiposity and increases lean and bone mass in male mice while decreasing generalized growth in female mice.

Binding characteristics of sodium saccharin with calf thymus DNA in vitro

The binding characteristics of sodium saccharin (SSA), an artificial sweetener, with calf thymus DNA (ctDNA) were investigated by multispectroscopic techniques, chemometrics, and molecular simulation. A combined fluorescence and UV-vis spectroscopic data matrix was resolved by the multivariate curve resolution-alternating least-squares (MCR-ALS) chemometrics algorithm. The MCR-ALS analysis extracted simultaneously the concentration profiles and spectra for the three components (SSA, ctDNA, and SSA-ctDNA complex) to quantitatively monitor the SSA-ctDNA interaction, which is difficult to perform by conventional spectroscopic approach. The binding mode of SSA to ctDNA was principally through groove binding as revealed by ctDNA melting temperature studies, viscosity measurements, and iodide and salt quenching effects. Analysis of the Fourier transform infrared and circular dichroism spectra as well as molecular docking indicated that SSA preferentially bound to the guanine base of ctDNA and led to a transformation from B-like DNA structure to A-like conformation. Moreover, gel electrophoresis results suggested that SSA did not induce any significant cleavage in plasmid DNA.

Synthesis of some new benzisothiazolone and benzenesulfonamide derivatives of biological interest starting from saccharin sodium

Two new series of benzenesulfonamide (4a-f, 5a-b, 6, 7) and 1,2-benzisothiazol-3(2H)-one-1,1-dioxide (9a-c, 10, 12a-d) derivatives were prepared starting from saccharin sodium. The novel compounds were characterized using elemental analyses and different spectroscopic methods. Assessment of the antiviral activities of these novel compounds against a broad panel of viruses in different cell cultures revealed that only the thiazole derivatives belonging to the benzisothiazol-3(2H)-one-1,1-dioxide series are the active ones. All thiazole derivatives 12a-d showed activity against both varicella-zoster virus, especially TK(-) VZV strain 07-1, and the cytomegalovirus strains AD-169 and Davis in human embryonic lung (HEL) cell culture.

Dynamic behavior of binary component ion-exchange displacement chromatography of proteins visualized by confocal laser scanning microscopy

Confocal laser scanning microscopy (CLSM) was introduced to visualize particle-scale binary component protein displacement behavior in Q Sepharose HP column. To this end, displacement chromatography of two intrinsic fluorescent proteins, enhanced green fluorescent protein (eGFP) and red fluorescent protein (RFP), were developed using sodium saccharin (NaSac) as a displacer. The results indicated that RFP as well as eGFP could be effectively displaced in the single-component experiments by 50 mmol/L NaSac at 120 and 140 mmol/L NaCl whereas a fully developed displacement train with eGFP and RFP was only observed at 120 mmol/L NaCl in binary component displacement. At 140 mmol/L NaCl, there was a serious overlapping of the zones of the two proteins, indicating the importance of induced-salt effect on the formation of an isotachic displacement train. CLSM provided particle-scale evidence that induced-salt effect occurred likewise in the interior of an adsorbent and was synchronous to the introduction of the displacer. CLSM results at 140 mmol/L NaCl also demonstrated that both the proteins had the same fading rate at 50 mmol/L NaSac in the initial stage, suggesting the same displacement ability of NaSac to both the proteins. In the final stage, the fading rate of RFP in the adsorbent became slow, particularly at lower displacer concentrations. In the binary component displacement, the two proteins exhibited distinct fading rates as compared to the single component displacement and the remarkable lagging of the fading rate was observed in protein displacements. It suggested that the co-adsorbed proteins had significant influence on the formation of an isotachic train and the displacement chromatography of the proteins. Therefore, this research provided particle-scale insight into the dynamic behavior and complexity in the displacement of proteins.

Experimental and theoretical vibrational investigation on the saccharinate ion in aqueous solution

We combined experimental vibrational spectroscopy (FTIR-Raman) and ab-initio calculations based on the density functional theory (DFT) to predict the structural and vibrational properties of sodium saccharinate in the solid and aqueous solution phases. The structural properties for the saccharinate ion and its dimer, such as the bond order, possible charge-transfer and the topological properties for both rings in the two media were studied by means of the Natural Bond Orbital (NBO) and the Atoms in Molecules theory (AIM) investigation. For a complete assignment of the IR and Raman spectra, the density functional theory calculations were combined with Pulay's scaled quantum mechanics force field (SQMFF) methodology in order to fit the theoretical frequency values to the experimental ones. An agreement between theoretical and available experimental results was found. Four intense bands in the infrared spectrum characteristic of the dimeric species of the compound were detected.

Preparation, structural analysis, and properties of tenoxicam cocrystals

Cocrystals of tenoxicam, a non-steroidal anti-inflammatory drug, are screened, prepared, and characterized in this study. Nine tenoxicam cocrystals were identified using solvent-drop grinding (SDG) techniques. Structural characterization was performed using powder X-ray diffraction (PXRD), differential scanning calorimetry, and multinuclear solid-state NMR (SSNMR). Thermal analysis, PXRD, and 1D SSNMR are used to detect solvates and phase mixtures encountered in SDG cocrystal screening. 2D SSNMR methods are then used to confirm cocrystal formation and determine structural aspects for selected cocrystals formed with saccharin, salicylic acid, succinic acid, and glycolic acid in comparison to Forms I and III of tenoxicam. Molecular association is demonstrated using cross-polarization heteronuclear dipolar correlation (CP-HETCOR) methods involving (1)H and (13)C nuclei. Short-range (1)H-(13)C CP-HETCOR and (1)H-(1)H double-quantum interactions between atoms of interest, including those engaged in hydrogen bonding, are used to reveal local aspects of the cocrystal structure. (15)N SSNMR is used to assess ionization state and the potential for zwitterionization in the selected cocrystals. The tenoxicam saccharin cocrystal was found to be similar in structure to a previously-reported cocrystal of piroxicam and saccharin. The four selected cocrystals yielded intrinsic dissolution rates that were similar or reduced relative to tenoxicam Form III.

Characterization of the modes of binding between human sweet taste receptor and low-molecular-weight sweet compounds

One of the most distinctive features of human sweet taste perception is its broad tuning to chemically diverse compounds ranging from low-molecular-weight sweeteners to sweet-tasting proteins. Many reports suggest that the human sweet taste receptor (hT1R2–hT1R3), a heteromeric complex composed of T1R2 and T1R3 subunits belonging to the class C G protein–coupled receptor family, has multiple binding sites for these sweeteners. However, it remains unclear how the same receptor recognizes such diverse structures. Here we aim to characterize the modes of binding between hT1R2–hT1R3 and low-molecular-weight sweet compounds by functional analysis of a series of site-directed mutants and by molecular modeling–based docking simulation at the binding pocket formed on the large extracellular amino-terminal domain (ATD) of hT1R2. We successfully determined the amino acid residues responsible for binding to sweeteners in the cleft of hT1R2 ATD. Our results suggest that individual ligands have sets of specific residues for binding in correspondence with the chemical structures and other residues responsible for interacting with multiple ligands.

CLM94, a novel cyclic amide with anti-VEGFR-2 and antiangiogenic properties, is active against primary anaplastic thyroid cancer in vitro and in vivo

CONTEXT AND OBJECTIVE

We have studied the antitumor activity of a novel cyclic amide, CLM94, with anti-vascular endothelial growth factor (VEGF) receptor-2 and antiangiogenic activity in primary anaplastic thyroid cancer (ATC) cells in vitro and in vivo.

DESIGN AND MAIN OUTCOME MEASURES

CLM94 was tested: 1) in two human cell lines (HMVEC-d, dermal microvascular endothelial cells; and 8305C, undifferentiated thyroid cancer) at 0.001-100 μm; 2) in ATC cells at the concentrations of 10, 30, and 50 μm; and 3) in an ATC cell line (AF) in CD nu/nu mice.

RESULTS

CLM94 significantly inhibited VEGF receptor-2 and epidermal growth factor receptor phosphorylation in HMVEC-d and proliferation in HMVEC-d and 8305C cells. A significant reduction of proliferation with CLM94 in ATC cells (P < 0.01, ANOVA) and a slight but significant reduction of proliferation with CLM94 30 and 50 μm in normal thyroid follicular cells (P < 0.01, ANOVA) were shown. CLM94 increased the percentage of apoptotic ATC cells dose-dependently (P < 0.001, ANOVA) and inhibited migration (P < 0.01) and invasion (P < 0.001). AF cell line was injected sc in CD nu/nu mice, and tumor masses became detectable 25 d afterward. CLM94 (40 mg/kg · d) significantly inhibited tumor growth (starting 10 d after the beginning of treatment). CLM94 significantly decreased the VEGF-A gene expression in the AF cell line and the VEGF-A protein and microvessel density in AF tumor tissues.

CONCLUSIONS

The antitumor and antiangiogenic activity of a new "cyclic amide" compound, CLM94, is very promising in ATC, opening the way to a future clinical evaluation.

A new naphthimidazole derivative for saccharide labeling with enhanced sensitivity in mass spectrometry detection

A series of saccharides, including maltoheptose, blood type B antigen, pullulan and the glucan of Ganoderma lucidum, are easily converted into the naphthimidazole (NAIM) derivatives in high yields by the iodine-promoted oxidative condensation. The NAIM-labeled saccharides, without further purification, show enhanced signals in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The combined use of NAIM derivatization and MALDI-TOFMS analysis thus provides a rapid method for identification of saccharides even in less than 1 pmol of saccharide in the sample. Characterization of the biologically active saccharides and complex polysaccharides is also achieved through the NAIM-derivatization method. This study can be further applied to facilitate the isolation and analysis of novel saccharides.

Structural characterization and EPR spectral studies on mononuclear copper(II) complex of saccharin with ethylnicotinate

Mononuclear copper(II) saccharinate (sac) complex containing ethylnicotinate (enc), [Cu(enc)(2)(sac)(2)(H(2)O)].1.4H(2)O has been synthesized and characterized by spectroscopic (IR, UV-vis, EPR), X-ray diffraction technique and electrochemical methods. It crystallizes in the tetragonal crystal systems with space group I4(1)cd and Z=8. The copper(II) ion presents a CuN(4)O distorted square pyramidal coordination. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values, calculated for title complex in polycrystalline state at 298 K and in frozen DMF (110K), indicate the presence of the unpaired electron in the d(x)(2)-(y)(2) orbital. The evaluated metal-ligand bonding parameters showed strong in-plane sigma and in-plane pi-bonding. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed. The cyclic voltammogram of the title complex investigated in DMF (dimethylformamide) solution exhibits only metal centred electroactivity in the potential range +/-1.25 V vs. Ag/AgCl reference electrode.

Crystal structure and EPR studies of mixed ligand complex of cobalt(II) with saccharin and ethylisonicotine

The tetraaquabis(ethylisonicotinate)cobalt(II) disaccharinate, [Co(ein)2(H2O)4].(sac)2, (CENS), (ein: ethylisonicotinate and sac: saccharinate) complex has been synthesized and its crystal structure has been determined by X-ray diffraction analysis. The title complex crystallizes in monoclinic system with space group P2(1)/c and Z=2. The Co(II) cations present a slightly distorted CoN2O4 octahedral environment, with equatorially coordinated water molecules and axially pyridine N-bound ethylisonicotinate ligands. The magnetic environments of Cu2+-doped Co(II) complex have been identified by electron paramagnetic resonance (EPR) technique. Cu2+-doped CENS single crystals have been studied at room temperature in three mutually perpendicular planes. The calculated results of the Cu2+-doped CENS indicate that Cu2+ ion substitute with the Co2+ ion in the host lattice. The angular variations of the EPR spectra have shown that two different Cu2+ complexes are located in different chemical environments, and each environment contains two magnetically inequivalent Cu2+sites in distinct orientations occupying substitutional positions in the lattice and show very high angular dependence. The cyclic voltammogram of the title complex investigated in dimethylformamide (DMF) solution exhibits only metal centered electroactivity in the potential range -1.0-1.25V versus Ag/AgCl reference electrode.

EPR study of Cu(2+)-doped tetraaqua-di(nicotinamide)Co(II) saccharinate single crystals

The electron paramagnetic resonance spectra of Cu(2+) impurities in [Co(nicotinamide)(2)(H(2)O)(4)](saccharinate)(2) single crystals have been studied at ambient temperature in three mutually perpendicular planes. The angular variation of the spectra shows that the Cu(2+) ion substitutes the Co(2+) site in the lattice. The EPR spectra of Cu(2+) ions are characteristic of tetragonally elongated octahedral site. The spin-Hamiltonien parameters were obtained from the single crystal EPR analysis. The ground-state wave function of Cu(2+) ion in the lattice has been constructed.

Dissolution improvement and the mechanism of the improvement from cocrystallization of poorly water-soluble compounds

PURPOSE

To demonstrate improvement in the dissolution of exemestane and megestrol acetate from cocrystallization using various particle sizes and to investigate the mechanism of the improved dissolution.

METHODS

Cocrystal screening was performed by slurry crystallization. The cocrystals were identified and characterized by powder X-ray diffraction, thermal analysis, and single crystal X-ray diffraction. Different particle sizes of each cocrystal were prepared from organic solutions. Solubility and dissolution rates were evaluated using dissolution tests. Transformation behavior of the cocrystals in suspension was analyzed by PXRD and polarization microscopy.

RESULTS

Two novel cocrystals were obtained: exemestane (EX)/maleic acid (MAL) (cocrystal 1) and megestrol acetate (MA)/saccharin (SA) (cocrystal 2). Cocrystal 1 showed a high dissolution rate even with large particles. Cocrystal 2 showed supersaturation with fine particles. The transformation from cocrystal 1 to EX was observed within 1 min in suspension. Cocrystal 2 was transformed to MA within 2-4 h.

CONCLUSIONS

Cocrystallizations of EX and MA improved initial dissolution rates compared to the respective original crystals. The mechanism of dissolution enhancement varied. With cocrystal 1, fine particle formation resulted in enhancement, whereas with cocrystal 2, enhancement was due to the maintenance of the cocrystal form and rapid dissolution before transformation to the original crystal.

Synthesis, Characterization and Antimycobacterial Activity of Ag(I)-Aspartame, Ag(I)-Saccharin and Ag(I)-Cyclamate Complexes

The present work describes the synthesis and antimycobacterial activity of three Ag(I)-complexes with the sweeteners aspartame, saccharin, and cyclamate as ligands, with the aim of finding new candidate substances for fighting tuberculosis and other mycobacterial infections. The minimal inhibitory concentration of these three complexes was investigated in order to determine their in-vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium malmoense, and Mycobacterium kansasii. The MIC values were determined using the Microplate Alamar Blue Assay. The best MIC values found for the complexes were 9.75 microM for Ag(I)-aspartame against M. kansasii and 15.7 microM for Ag(I)-cyclamate against M. tuberculosis.

EPR spectra of Cu(2+) doped [Zn(sac)2(dmen)] and [Zn(sac)2(paen)] single crystals

Cu(2+) doped single crystals of [Zn(sac)2(dmen)] (sac: saccharinate, dmen: N,N'-dimethylethylendiamine) and [Zn(sac)2(paen)], (paen: N,N'-bis(3-propylamine)ethylendiamine) complexes have been investigated by electron paramagnetic resonance (EPR) technique. Detailed investigations of the EPR spectra indicate that Cu(2+) ion substitute with Zn(2+) ion and forms tetrahedral complex in [Zn(sac)2(dmen)] and octahedral complex in [Zn(sac)2(paen)] hosts. Principal values of the g and hyperfine tensors are determined and the ground state wave functions of Cu(2+) ions are obtained using EPR parameters.

Indomethacin-saccharin cocrystal: design, synthesis and preliminary pharmaceutical characterization

PURPOSE

To design and prepare cocrystals of indomethacin using crystal engineering approaches, with the ultimate objective of improving the physical properties of indomethacin, especially solubility and dissolution rate.

MATERIALS AND METHODS

Various cocrystal formers, including saccharin, were used in endeavours to obtain indomethacin cocrystals by slow evaporation from a series of solvents. The melting point of crystalline phases was determined. The potential cocrystalline phase was characterized by DSC, IR, Raman and PXRD techniques. The indomethacin-saccharin cocrystal (hereafter IND-SAC cocrystal) structure was determined from single crystal X-ray diffraction data. Pharmaceutically relevant properties such as the dissolution rate and dynamic vapour sorption (DVS) of the IND-SAC cocrystal were evaluated. Solid state and liquid-assisted (solvent-drop) cogrinding methods were also applied to indomethacin and saccharin.

RESULTS

The IND-SAC cocrystals were obtained from ethyl acetate. Physical characterization showed that the IND-SAC cocrystal is unique vis-à-vis thermal, spectroscopic and X-ray diffraction properties. The cocrystals were obtained in a 1:1 ratio with a carboxylic acid and imide dimer synthons. The dissolution rate of IND-SAC cocrystal system was considerably faster than that of the stable indomethacin gamma-form. DVS studies indicated that the cocrystals gained less than 0.05% in weight at 98%RH. IND-SAC cocrystal was also obtained by solid state and liquid-assisted cogrinding methods.

CONCLUSIONS

The IND-SAC cocrystal was formed with a unique and interesting carboxylic acid and imide dimer synthons interconnected by weak N-Hcdots, three dots, centeredO hydrogen bonds. The cocrystals were non-hygroscopic and were associated with a significantly faster dissolution rate than indomethacin (gamma-form).

DirectedOrthoMetalation−Cross Coupling Strategies.N-Cumyl Arylsulfonamides. Facile Deprotection and Expedient Route to 7- and 4,7-Substituted Saccharins⊥

By using the powerful N-cumylsulfonamide directed metalation group (DMG), a series of 2-substituted derivatives were prepared according to the directed ortho metalation (DoM) tactic (Table 1). Mild conditions for N-decumylation and other simple transformations of the products have been achieved (Scheme 2). The 3-silyloxy sultam 12 undergoes further DoM to give formyl, thiomethyl, iodo, and amide derivatives 13a-g of potential value for saccharin synthesis (Table 2). An effective route to target 7-aryl saccharins via Suzuki cross coupling (Table 3) followed by further metalation-carbamoylation and cyclization (Table 5) is described. 4,7-Disubstituted saccharins have been obtained by similar sequences (Scheme 3). Mild TFA-mediated N-decumylation furnishes substituted primary arylsulfonamides (Table 4).

Relationships between insulin release and taste

Tasting sweet food elicits insulin release prior to increasing plasma glucose levels, known as cephalic phase insulin release (CPIR). The characteristic of CPIR is that plasma insulin secretion occurs before the rise of the plasma glucose level. In this experiment, we examined whether taste stimuli placed on the tongue could induce CPIR. We used female Wistar rats and five basic taste stimuli: sucrose (sweet), sodium chloride (salty), HCl (sour), quinine (bitter) or monosodium glutamate (umami). Rats reliably exhibited CPIR to sucrose. Sodium chloride, HCl, quinine, or monosodium glutamate did not elicit CPIR. The non-nutritive sweetener saccharine elicited CPIR. However, starch, which is nutritive but non-sweet, did not elicit CPIR although rats showed a strong preference for starch which is a source of glucose. In addition, we studied whether CPIR was related to taste receptor cell activity. We carried out the experiment in rats with bilaterally cut chorda tympani nerves, one of the gustatory nerves. After sectioning, CPIR was not observed for sweet stimulation. From these results, we conclude that sweetness information conducted by thistaste nerve provides essential information for eliciting CPIR.

Synthesis, antimycobacterial and antitumor activities of new (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)methyl N,N-disubstituted dithiocarbamate/O-alkyldithiocarbonate derivatives

Reaction of 2-chloromethylsaccharin with substituted potassium dithiocarbamates and substituted potassium dithiocarbonates furnished (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)methyl N,N-disubstituted dithiocarbamates (4-15) and (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)methyl O-alkyldithiocarbonates (16-20). The new derivatives were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Compounds 4-13, 15, and 16-20 described herein showed moderate to good inhibitory activity. In particular, seven analogs 4, 5, 6, 13, and 7, 8, and 12 exhibited excellent MIC values of 1.56 and 0.78 microg/mL, respectively. Compounds 4, 5, 10, 12, 13, and 16 were selected and screened for antitumor activity. Among the tested compounds, 4 and 5 were found to be cytotoxic, especially against leukemia cell lines CCRF-CEM, HL-60(TB), RPMI-8226, and SR with log10GI50 values lower than -6.69, and against non-small cell lung cancer NCI-H522 cell line with log10GI50 values lower than -6.31. Compound 10 was cytotoxic against leukemia cell line HL-60(TB), whereas 16 displayed favorable cytotoxicity against ovarian cancer cell line OVCAR-3 with log10GI50 values of -6.31 and -7.45, respectively.

Cocrystal Formation during Cogrinding and Storage is Mediated by Amorphous Phase

PURPOSE

The purpose of this work was to investigate the mechanisms of cocrystal formation during cogrinding and storage of solid reactants, and to establish the effects of water by cogrinding with hydrated form of reactants and varying RH conditions during storage.

METHODS

The hydrogen bonded 1:1 carbamazepine-saccharin cocrystal (CBZ-SAC) was used as a model compound. Cogrinding of solid reactants was studied under ambient and cryogenic conditions. The anhydrous, CBZ (III), and dihydrate forms of CBZ were studied. Coground samples were stored at room temperature at 0% and 75% RH. Samples were analyzed by XRPD, FTIR and DSC.

RESULTS

Cocrystals prepared by cogrinding and during storage were similar to those prepared by solvent methods. The rate of cocrystallization was increased by cogrinding the hydrated form of CBZ and by increasing RH during storage. Cryogenic cogrinding led to higher levels of amorphization than room temperature cogrinding. The amorphous phase exhibited a T (g) around 41 degrees C and transformed to cocrystal during storage.

CONCLUSIONS

Amorphous phases generated by pharmaceutical processes lead to cocrystal formation under conditions where there is increased molecular mobility and complementarity. Water, a potent plasticizer, enhances the rate of cocrystallization. This has powerful implications to control process induced transformations.

Effects of an artificial sweetener on health, performance, and dietary preference of feedlot cattle1

Two experiments examined the effects of a saccharin-based artificial sweetener (Sucram) on health, performance, and dietary preference of feedlot cattle. In Exp. 1, 200 steer calves (initial BW = 190.4 +/- 1.47 kg) were fed a 65% concentrate diet supplemented with or without 200 mg of Sucram/kg (DM basis) during a 56-d receiving-growing period. Feeding Sucram did not affect overall (P = 0.19) DMI; however, from d 29 to 56, there was a trend (P = 0.10) for increased DMI with Sucram (5.71 vs. 6.02 kg/d, respectively). From d 0 to 28 and d 0 to 56, there were trends (P = 0.11 and 0.12, respectively) for increased ADG and for increased d-56 BW (P = 0.07) for calves fed Sucram. No differences were detected (P = 0.82) for receiving (REC) period morbidity. During the finishing (FIN) period, 180 steers from the REC period were assigned (9 pens/treatment in a 2 x 2 factorial design) to the following treatments: 1) control REC/control FIN; 2) control REC/Sucram FIN; 3) Sucram REC/control FIN; and 4) Sucram REC/ Sucram FIN. Over the FIN period, ADG tended (P = 0.12) to be greater for Sucram; however, carcass-adjusted ADG did not differ among treatments. Daily DMI was affected by a REC x FIN interaction (P = 0.08), which was the result of greater DMI by cattle in the Sucram REC/Sucram FIN treatment and decreased DMI by cattle in the Sucram REC/control FIN treatment. In general, changes in carcass characteristics were minor. In Exp. 2, 12 steers (initial BW = 395.6 +/- 6.17 kg) were used in a simultaneously replicated 3 x 3 Latin square preference test. Each square consisted of 3 pens, with 2 steers/pen, and 3 time periods. Bunks had dividers at their midpoint, and equal quantities of diet (as-fed basis) were delivered randomly on either side of the divider daily. Treatments were: 1) control; 2) Sucram = basal diet supplemented with 200 mg of Sucram/kg of DM; and 3) choice = control and Sucram on separate sides of the divider. Dietary preference differed on d 1 (P = 0.01) and d 3 (P = 0.02) for control vs. choice and Sucram vs. choice, with the choice group consuming 0.49 and 1.72 kg of DM more of the Sucram diet than the control diet, respectively. This effect, however, was not consistent across days, and average DMI did not differ (P = 0.81) among treatments. Addition of Sucram to the diet of newly received cattle tended to increase receiving period ADG; however, its effects on morbidity, finishing performance, and dietary preference were limited.

Electron paramagnetic resonance studies of Cu2+ ion in tetraaqua-di(nicotinamide)Ni(II)-saccharinates single crystals

X-band (approximately 9.8 GHz) electron paramagnetic resonance (EPR) measurement at ambient temperature in three mutually perpendicular planes have been carried out on a single crystal of Cu2+ doped mixed ligand complex of Ni(II) with saccharin and nicotinamide [Ni(Nic)2(H2O)4](sac)2. The angular dependent spectra showed that the Cu2+ ion enters Ni2+ sites in the lattice and distorted local environment of Ni2+ site. The principal g and A values, covalency parameter (alpha'2), mixing coefficients (alpha and beta) and Fermi contact term (K) have been evaluated from the EPR analysis. The ground-state wave function of the Cu2+ ion has been constructed using the alpha'2, alpha and beta values. The nature of the distortion present in the lattice is obtained from the values of the mixing coefficients.

Solid-state architecture of saccharin salts of some diamines

Hydrazinium saccharinate, N2H5+.C7H4NO3S-, crystallizes in a 1:1 ratio, while ethylenediaminium bis(saccharinate), C2H10N2(2+).2C7H4NO3S-, and butane-1,4-diaminium bis(saccharinate), C4H14N2(2+).2C7H4NO3S-, form in a 1:2 cation-anion stoichiometry. The structures contain many strong hydrogen bonds of the N+-H...N-, N+-H...O, N-H...O and N-H...N types, with auxiliary C-H...O interactions.