Matthew Allan - Academia.edu (original) (raw)

Papers by Matthew Allan

Food Chemistry, 2015

Many crystalline food ingredients undergo dissolution at a critical relative humidity known as th... more Many crystalline food ingredients undergo dissolution at a critical relative humidity known as the deliquescence point (RH0). Blends of crystalline ingredients exhibit deliquescence lowering, resulting in a deliquescence point (RH0mix) lower than the individual ingredient RH0s. To determine the effects of method type and data collection parameters, these deliquescence measurement methods were compared: saturated solution water activity, dynamic vapor sorption profiles (DVS), and dynamic dewpoint sorption profiles (DDI). Water activity measurements were broadly applicable for measuring deliquescence points when 1-4g sample, 50-125μL/g water:solid ratio, and 24-48h equilibration were used. DVS and DDI techniques should be limited to samples containing 1-2 ingredients due to crystal contact point effects on RH0mix measurement. Recommended DVS parameters are: 1% RH step, 0.01% equilibrium criteria, and 3h maximum time. DDI profiles were consistent with 50-150mL/min vapor flow rates. Ingredient mutarotation, solute interactions in solution, and contact point limitations affect the determination of deliquescence points.

Food Chemistry, 2015

Deliquescence points (RH0, RH0mix) of ionic crystalline food ingredients and blends thereof were ... more Deliquescence points (RH0, RH0mix) of ionic crystalline food ingredients and blends thereof were determined using water activity and moisture sorption techniques. Measured RH0mix values of ingredient blends with and without a common ion were compared to Ross equation predictions of deliquescence lowering. In binary blends with no common ion, measured RH0mix values ranged from 5% RH lower to 6% RH higher than predicted; however, when a common ion was present, the measured RH0mix was consistently 6-8% RH higher than predicted. In tertiary blends with a common ion, RH0mix values were 15-18% RH higher than predicted. The higher RH0mix in blends with a common ion is caused by counterion dissociation competition from the common ion. At equilibrium, these solutions will have fewer solutes and a greater vapor pressure than assumed by the Ross equation. A modified Ross equation was developed to compensate for the common-ion effect and improve RH0mix predictions.

Bioorganic & Medicinal Chemistry Letters, 2006

3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles were discovered as potent in vitro MEK1 ... more 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles were discovered as potent in vitro MEK1 inhibitors.

Bioorganic & Medicinal Chemistry Letters, 2006

The development of potent, orally bioavailable, and selective series of 5-amino-3-hydroxy-N(1-hyd... more The development of potent, orally bioavailable, and selective series of 5-amino-3-hydroxy-N(1-hydroxypropane-2-yl)isothiazole-4-carboxamidine inhibitors of MEK1 and MEK-2 kinase is described. Optimization of the carboxamidine and the phenoxyaniline group led to the identification of 55 which gave good potency as in vitro MEK1 inhibitors, and good oral exposure in rat.

Bioorganic & Medicinal Chemistry Letters, 2006

A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 ... more A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 isolates. Several of these compounds exhibited potent antiviral activities against efavirenz-and nevirapine-resistant viruses, containing K103N and/or Y181C mutations or Y188L mutation. Triazoles were first synthesized from commercially available substituted phenylthiosemicarbazides, then from isothiocyanates, and later by condensing the desired substituted anilines with thiosemicarbazones.

Journal of Astm International, 2009

Surface & Coatings Technology, 1997

Investigations concerning the microstructure and mechanical properties of alumina coatings have b... more Investigations concerning the microstructure and mechanical properties of alumina coatings have been performed. Alumina coatings have been deposited by both ionized reactive magnetron sputtering (l&B) and conventional reactive magnetron sputtering (CMS) in an argon/ oxygen discharge onto stainless-steel coated silicon substrates. X-Ray diffraction (XRD) was used for the phase analysis, and nanoindentation was used to evaluate the mechanical properties. Substrate temperature during deposition was <5OO"C, which is the technologically interesting temperature range to coat temperature sensitive substrates such as tool steels. The phase transformation temperatures from amorphous to K-alumina containing films was found to be between 43O'C and 472'C, and the transition temperature was lower for higher ion currents. A film containing a mixture of K-and B-alumina phases was grown at 430°C. The crystalline film hardness was 22 k 1 GPa.

Bioorganic & Medicinal Chemistry Letters, 2006

A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 ... more A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 isolates. Several of these compounds exhibited potent antiviral activities against efavirenz-and nevirapine-resistant viruses, containing K103N and/or Y181C mutations or Y188L mutation. Triazoles were first synthesized from commercially available substituted phenylthiosemicarbazides, then from isothiocyanates, and later by condensing the desired substituted anilines with thiosemicarbazones.

Bioorganic & Medicinal Chemistry Letters, 2006

Thiazole derivatives R 0260 Discovery of 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles... more Thiazole derivatives R 0260 Discovery of 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles as Potent MEK1 Inhibitors. -Isothiazole derivative (Ic) shows more than 180-fold improvement in vitro inhibition of MEK1 compared to the initial lead structure. -(VARAPRASAD*, C. V. N. S.; et al.; Bioorg. Med. Chem. Lett. 16 (2006) 15, 3975-3980; Drug Discovery, Valeant Pharm. Res. Dev.,

Food Chemistry, 2015

Many crystalline food ingredients undergo dissolution at a critical relative humidity known as th... more Many crystalline food ingredients undergo dissolution at a critical relative humidity known as the deliquescence point (RH0). Blends of crystalline ingredients exhibit deliquescence lowering, resulting in a deliquescence point (RH0mix) lower than the individual ingredient RH0s. To determine the effects of method type and data collection parameters, these deliquescence measurement methods were compared: saturated solution water activity, dynamic vapor sorption profiles (DVS), and dynamic dewpoint sorption profiles (DDI). Water activity measurements were broadly applicable for measuring deliquescence points when 1-4g sample, 50-125μL/g water:solid ratio, and 24-48h equilibration were used. DVS and DDI techniques should be limited to samples containing 1-2 ingredients due to crystal contact point effects on RH0mix measurement. Recommended DVS parameters are: 1% RH step, 0.01% equilibrium criteria, and 3h maximum time. DDI profiles were consistent with 50-150mL/min vapor flow rates. Ingredient mutarotation, solute interactions in solution, and contact point limitations affect the determination of deliquescence points.

Food Chemistry, 2015

Deliquescence points (RH0, RH0mix) of ionic crystalline food ingredients and blends thereof were ... more Deliquescence points (RH0, RH0mix) of ionic crystalline food ingredients and blends thereof were determined using water activity and moisture sorption techniques. Measured RH0mix values of ingredient blends with and without a common ion were compared to Ross equation predictions of deliquescence lowering. In binary blends with no common ion, measured RH0mix values ranged from 5% RH lower to 6% RH higher than predicted; however, when a common ion was present, the measured RH0mix was consistently 6-8% RH higher than predicted. In tertiary blends with a common ion, RH0mix values were 15-18% RH higher than predicted. The higher RH0mix in blends with a common ion is caused by counterion dissociation competition from the common ion. At equilibrium, these solutions will have fewer solutes and a greater vapor pressure than assumed by the Ross equation. A modified Ross equation was developed to compensate for the common-ion effect and improve RH0mix predictions.

Bioorganic & Medicinal Chemistry Letters, 2006

3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles were discovered as potent in vitro MEK1 ... more 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles were discovered as potent in vitro MEK1 inhibitors.

Bioorganic & Medicinal Chemistry Letters, 2006

The development of potent, orally bioavailable, and selective series of 5-amino-3-hydroxy-N(1-hyd... more The development of potent, orally bioavailable, and selective series of 5-amino-3-hydroxy-N(1-hydroxypropane-2-yl)isothiazole-4-carboxamidine inhibitors of MEK1 and MEK-2 kinase is described. Optimization of the carboxamidine and the phenoxyaniline group led to the identification of 55 which gave good potency as in vitro MEK1 inhibitors, and good oral exposure in rat.

Bioorganic & Medicinal Chemistry Letters, 2006

A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 ... more A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 isolates. Several of these compounds exhibited potent antiviral activities against efavirenz-and nevirapine-resistant viruses, containing K103N and/or Y181C mutations or Y188L mutation. Triazoles were first synthesized from commercially available substituted phenylthiosemicarbazides, then from isothiocyanates, and later by condensing the desired substituted anilines with thiosemicarbazones.

Journal of Astm International, 2009

Surface & Coatings Technology, 1997

Investigations concerning the microstructure and mechanical properties of alumina coatings have b... more Investigations concerning the microstructure and mechanical properties of alumina coatings have been performed. Alumina coatings have been deposited by both ionized reactive magnetron sputtering (l&B) and conventional reactive magnetron sputtering (CMS) in an argon/ oxygen discharge onto stainless-steel coated silicon substrates. X-Ray diffraction (XRD) was used for the phase analysis, and nanoindentation was used to evaluate the mechanical properties. Substrate temperature during deposition was <5OO"C, which is the technologically interesting temperature range to coat temperature sensitive substrates such as tool steels. The phase transformation temperatures from amorphous to K-alumina containing films was found to be between 43O'C and 472'C, and the transition temperature was lower for higher ion currents. A film containing a mixture of K-and B-alumina phases was grown at 430°C. The crystalline film hardness was 22 k 1 GPa.

Bioorganic & Medicinal Chemistry Letters, 2006

A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 ... more A new series of 1,2,4-triazoles was synthesized and tested against several NNRTI-resistant HIV-1 isolates. Several of these compounds exhibited potent antiviral activities against efavirenz-and nevirapine-resistant viruses, containing K103N and/or Y181C mutations or Y188L mutation. Triazoles were first synthesized from commercially available substituted phenylthiosemicarbazides, then from isothiocyanates, and later by condensing the desired substituted anilines with thiosemicarbazones.

Bioorganic & Medicinal Chemistry Letters, 2006

Thiazole derivatives R 0260 Discovery of 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles... more Thiazole derivatives R 0260 Discovery of 3-Hydroxy-4-carboxyalkylamidino-5-arylamino-isothiazoles as Potent MEK1 Inhibitors. -Isothiazole derivative (Ic) shows more than 180-fold improvement in vitro inhibition of MEK1 compared to the initial lead structure. -(VARAPRASAD*, C. V. N. S.; et al.; Bioorg. Med. Chem. Lett. 16 (2006) 15, 3975-3980; Drug Discovery, Valeant Pharm. Res. Dev.,