Selective determination of aloin in different matrices by HPTLC densitometry in fluorescence mode.

A novel method based on the fluorescence excited solely on aloin by a H₃BO₃ derivatizing procedure, allowed its rapid and selective determination among the co-occurring components in a variety of complex matrices as several Aloes dried extracts and related commercial products. HPTLC LiChrospher silica gel 60 F254S, 20 cm x 10 cm, plates with ethyl formate: CH₃OH:H₂O (100:14.5:10, v/v) as the mobile phase were used.

High throughput headspace GC-MS quantitative method to measure the amount of carbon monoxide in treated tuna fish.

A robust and dependable headspace HS-GC-MS method has been developed for the determination of carbon monoxide (CO) treated tuna fish. The performance of the method has been evaluated by analyzing spiked and blank samples. The proposed method uses a programmed temperature vaporizing (PTV) injector to implement the HS injection and overcome the negative effects on the column of water contained in the sample.

Physico-chemical and structural characterization of diacerhein.

The physico-chemical and structural characterization of diacerhein, an anthraquinone with antiinflammatory activity, employed in the symptomatic treatment of inflammatory osteoarthritis, is reported. The combined use of FT-IR, DSC, X-ray powder and single-crystal diffraction has provided a valuable tool to fully characterize the title compound. The X-ray diffraction study has revealed the existence of hydrogen-bond assisted tight packing of the quasi-planar molecules in the solid.

Validation of a reversed phase high performance thin layer chromatographic-densitometric method for secoisolariciresinol diglucoside determination in flaxseed.

The validation of a HPTLC-densitometric method for the determination of secoisolariciresinol diglucoside (SDG) in flaxseed was performed improving the reproducibility of a previously reported HPTLC densitometric procedure by the use of fully wettable reversed phase plates (silica gel 60 RP18W F(254S), 10cmx10cm) with MeOH:HCOOH 0.1% (40:60, v/v) mobile phase. The analysis required only the alkaline hydrolysis in aqueous medium of undefatted samples and densitometry at 282nm of HPTLC runs.

Diisoprop-yl{2-[2-(2-oxopyrrolidin-1-yl)acetamido]eth-yl}ammonium hydrogen sulfate.

The structure of the title compound, C(14)H(28)N(3)O(2) (+)·HSO(4) (-), a nootropic drug (pramiracetam) investigated for cognition-enhancing properties, is closely similar to that of the previously determined acetonitrile solvate, both structures being characterized by the presence of ribbons of hydrogen-bonded ions. The pyrrolidine ring adopts an envelope conformation.

3-Methyl-1,4-dioxo-1,4-dihydro-naphthalen-2-yl 4-amino-benzoate.

The crystal structure of the title compound, C(18)H(13)NO(4), the oxidized form of the drug aminaftone used in venous disease therapy, is characterized by the presence of ribbons of hydrogen-bonded mol-ecules parallel to the [111] crystallographic direction and by stacking inter-actions between rings [centroid-centroid distance between quinone rings = 3.684 (3) Å and between amino-benzoate rings = 4.157 (3) Å] along the ribbons.

A convenient route to the synthesis of isotopomeric dihydro-2(3H)furanones.

A general synthetic procedure leading to isotopomeric dihydro-2(3H)furanones (gamma-butyrolactones) containing two, four, or six deuterium atoms has been developed. The labeled dihydro-2(3H)furanones were synthesized in quantitative yield from the saturated diacid C4 (succinic) or unsaturated diacids C4 (fumaric, maleic, or acetylendicarboxylic) in the presence of Ru4H4(CO)8(PBu3)4 using a deuterium pressure of 180 bar at 180 degrees C. This methodology was applied to the total synthesis of a hexadeuterated matairesinol lignan: The 3,4-bis[[3-methoxy-4-(phenylmethoxy)phenyl]methyl]dihydro-2(3H)furanone-[7,7',8,8',9',9'-D6] (benzyl-protected matairesinol-D6) was fully characterized.

A validated HPLC stability-indicating method for the determination of diacerhein in bulk drug substance.

A novel stability-indicating high-performance liquid chromatographic (HPLC) method was developed and validated for the assay of diacerhein in bulk forms. Diacerhein was found to degrade in alkaline and acidic conditions and also under oxidative stress. The drug was stable to dry heat and in presence of light.

High-performance thin-layer chromatographic-densitometric determination of secoisolariciresinol diglucoside in flaxseed.

A HPTLC-densitometric method, based on an external standard approach, was developed in order to obtain a novel procedure for routine analysis of secoisolariciresinol diglucoside (SDG) in flaxseed with a minimum of sample pre-treatment. Optimization of TLC conditions for the densitometric scanning was reached by eluting HPTLC silica gel plates in a horizontal developing chamber. Quantitation of SDG was performed in single beam reflectance mode by using a computer-controlled densitometric scanner and applying a five-point calibration in the 1.