Purification of Xenogeneic Bone Matrix by Extraction with Supercritical Carbon Dioxide and Evaluation of the Obtained Material

An environmentally friendly method of osteoplastic material production is proposed for reconstructive surgery needs based on treatment of xenogeneic bone matrix with supercritical carbon dioxide. The method provides the best extraction of lipids and fatlike substances at minimum cost of extracting agent and processing time; it allows the significant reduction of costs and facilitates the manufacture of surgical implants. The advantages of the obtained material in comparison with the known commercial analogue are demonstrated by in vitro experiments on the cellular model.     

Electronic structure of clusters of 3d elements in layered oxide systems

Sverdlovak State Pedagogical Institute. Institute of Chemistry, Ural Branch, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 1, pp. 20–25, January–February, 1991.     

MALDI-TOF MS as a label-free approach to rapid inhibitor screening

Mass Spectrometry (MS) has been widely reported for measuring the conversion of substrates to products for enzyme assays. These measurements are typically performed by time-consuming LC-MS to eliminate buffer salts that interfere with electrospray ionization MS. However, matrix-assisted laser desorption ionization, time-of-flight MS (MALDI-TOF MS) offers a label-free and direct readout of substrate and product, a fast sampling rate, and is tolerant of many buffer salts, reagents, and compounds that are typically found in enzyme reaction mixtures. In this report, a demonstration of how MALDI-TOF MS can be used to directly measure ratios of substrates and products to produce IC(50) curves for rapid enzyme assays and compound screening is provided. Typical reproducibility parameters were <7% RSD-a value comparable to ESI MS quantitative assays and well within the acceptable limits for screening assays. The speed of the MALDI readout is currently about 10 s per sample, thus allowing for over 7500 samples/day. From a simplicity standpoint, the enzymatic reaction mixtures are prepared by liquid handling robots, the reactions are stopped by addition of a 10 times volume of acidic matrix solution, and the samples are simultaneously transferred to MALDI target plate for analysis. Importantly, the ratios of substrate to product are of sufficient reproducibility to eliminate the need for internal standards and, thus, minimize the cost and increasing the speed of assay development.     

One-pot multicomponent synthesis of diversely substituted 2-aminopyrroles. A short general synthesis of rigidins A, B, C, and D

Privileged medicinal scaffolds based on the structures of tetra- and pentasubstituted 2-aminopyrroles were prepared via one-pot multicomponent reactions of structurally diverse aldehydes and N-(aryl-, hetaryl-, alkylsulfonamido)acetophenones with activated methylene compounds. This methodology was used in a four-step synthesis of alkaloids rigidins A, B, C, and D in overall yields of 61%, 58%, 60%, and 53%, respectively. Of these, rigidins B, C, and D were synthesized for the first time.     

Swelling of acrylate hydrogels filled with brushite and octacalcium phosphate

Hydrogels filled with CaHPO₄ · 2H₂O and Ca₈(HPO₄)₂(PO₄)4 · 5H₂O were synthesized from the acrylate derivatives of poly(ethylene glycol) by the photopolymerization method. The swelling behaviour of the filled and unfilled hydrogels in water was studied. The solubility of the photoinitiator in water and in the monomers was estimated.