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The physico-mechanical, chemical and mineralogical characteristics of volcanic glass (perlite) from the Mariovo region (Macedonia) as well as the mineralogical changes that occur during its thermal treatment were investigated to demonstrate its utilization for industrial use. The native perlite was characterized by chemical analysis, X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, thermal analysis (TGA/DTA), scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), and solid-state NMR. The chemical examination suggests that the perlite represents an acidic volcanic rock with a high percentage of SiO 2 (72.45%), high in alkali metal oxides (4.21 wt.% K 2 O, 3.56 wt.% Na 2 O), with a loss of ignition 3.54 wt.%. Results from the XRPD indicated major amorphous behaviour, with low amounts of feldspars, quartz, and cristobalite. SEM examinations revealed glassy structure with presence of certain pores (dimensions ranging from 50-100 μm). The determined expansion coefficient was 20 times its original volume. XRPD of expanded perlite compared to the native perlite depicted new intensive peaks of cristobalite. SEM and TEM revealed irregular morphology with broken or ragged edges. On the basis of the chemical and mineralogical composition, the studied perlite is classified as an appropriate material suitable as ceramic flux to lower the sintering temperature.

Potential antiproliferative effect of isoxazolo-and thiazolo coumarin derivatives on breast cancer mediated bone and lung metastasesThe study highlights the current progress in the development of coumarin scaffolds for drug discovery as novel anticancer agents in metastatic breast cancer. Eight compounds, combining the coumarin core and five membered heterocycles (isoxazoles and thiazoles) in hydrazinyldiene--chroman-2,4-diones, were characterized in terms of a potential antiproliferative effect on bone (SCP1833) and lung (SCP4175) metastatic breast cancer cell lines using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Cell viability was evaluated after 48 and 72 h of treatment and the 50 % inhibitory concentrations were determined. The results demonstrated dose-and time-dependent activity, with the most potent molecules having a thiazole moiety, without or with additional methyl group(s) attached to the carbon(s) at position(s) 5 and/or 4 in the thiazole ring. These molecules possessed significantly higher potency against both test cell lines compared to 4-hydroxycoumarin.

This study evaluates the effects of previously synthesized hydrazinyldiene-chroman-2,4-diones on cell proliferation and apoptosis, cell cycle distribution and migration capacity of MCF-7 breast cancer cells in synergy with doxorubicin. Physicochemical properties of the synthesized compounds were correlated with their structure and activity. Significant cell viability decrease in comparison with the effect of doxorubicin alone and the reference 4-hydroxycoumarin was observed when combination treatment comprising doxorubicin and the title compounds was applied. Synergistic effect with doxorubicin was also observed in down-regulation of phospho-Thr 308Akt levels, confirming reduced proliferation and increased apoptosis. Combined treatment increased the percentage of cells arrested at the G 2 /M stage. Additive inhibition of cell migration was also observed, pointing to the possibility of reducing the risk of metastases. With their solubility profile and log D 7.4 , all the synthesized compounds follow Lipinski's rule of five for good permeability (absorption) potential.

An improved synthetic method affording 4-chlorocoumarin-3-sulfonyl chloride (4) in very good yield (ca. 85 %) is reported. This compound was reacted with various bidentate nucleophiles such as 2-aminopyridines and 2-aminothiazoles in order to obtain substituted pyrido-and thiazino-1,2,4-thiadiazino-benzopyranone dioxides (potential anticancer and anti-HIV agents). These reactions occurred rapidly at room temperature giving yellowish precipitates, which are insoluble in common organic solvents, making the purification process challenging. Further investigation has shown that these fused heterocycles are not stable and decompose with opening of the 1,2,4-thiadiazine ring.