Mechanochemical Activation of Polymetallic Ore and Further Selective Floatation

It has been demonstrated that shock-vibrating activation of minerals is a prospective method to impact the ore; it may be used to intensify chemical and physical-chemical processes of mineral raw material processing and preparation. Differences in the composition and phase properties, obtained both in terms of continuous and periodic modes, are in the fact that in the first case loadings deal with interlayer space preserving layered nature of the mineral. When the mode is continuous, then the disturbances cover the octahedral layer though elementary constituent – tetrahedrons – are preserved. It has emerged that the most important advantage of high reacting capability of activated minerals is in the fact that leaching of some ores may be performed in chlorhydric acid at the expense of transformation of some silicate components into a specific state – loose packing of basic silicate chain. Consequently, shock-vibrating activation has become a basis to develop a method of leaching process intensification as well as a method to control phase formation.

Rhodosporidium sp. GROWTH IN MOLASSES MEDIUM AND EXTRACTION OF ITS ASTAXANTHIN BY USING HCl

Astaxanthin is classified as a xanthophyll-carotenoid, which is red-orange colour and powerful antioxidant activity. In this study, astaxanthin was collected from Rhodosporidum sp. by pilot culture (10 liters). Molasses medium was investigated with urea ((NH4)2CO), magnesium sulfate heptahydrate (MgSO4.7H2O) and potassium dihydrogen phosphate (KH2PO4) at different concentrations. Astaxanthin was extracted by using chlorhydric acid (HCl) method.The highest dried yeast biomass was 8.3682 g/l culture supernatant and astaxathin was 1.932 g/l culture supernatant by molasses medium containing 20 g/l sugar, 0.5 g/l ((NH4)2CO, 3 g/l MgSO4.7H2O and 10 % (v/v) inoculum. HCl extraction method was mixed 10 mg biomass: 1 ml HCl 0.6 N and incubated at 70 oC, 150 minutes.

Évolution des teneurs en polyamines libres et conjuguées dans les feuilles de vigne (Vitis vinifera 'Cabernet Sauvignon') saine et atteinte d'eutypiose

Effects of Eutypa lata, the fungal agent of eutypiosis, on polyamine (putrescine (Put), spermidine (Spd), spermine (Spm), diaminopropane (Dap)) and tyramine (Tyr) contents in grapevine leaves were studied to determine the relationship between these components and disease development. The external symptoms of eutypiosis are small and necrotic leaves, which could be observed on only one arm or on two arms of the vine stock. This study was carried out on healthy leaves (S, borne by healthy vine stock), apparently healthy leaves (Aps, borne by one arm without symptoms, whereas the other arm was diseased), and moderately (M. mal.) and strongly (F. mal.) diseased leaves. We analysed free polyamines (free PAs, chlorhydric acid soluble fraction), conjugated polyamines (PAs-fpm, PAs covalently linked to molecules with low molecular mass like hydroxycinnamic acids), and bound polyamines (PAs-mm, covalently linked to macromolecules) in Vitis vinifera L. 'Cabernet sauvignon', a variety sensitive to eutypiosis. In diseased leaves, we noted a decrease of free PAs, PAs-fpm, free Tyr, and Tyr-fpm levels. By contrast, the Dap-fpm level was increased by the disease. Eutypiosis also induced an increase of Spm-mm and Dap-mm levels, whereas the Put-mm and Spd-mm levels were decreased. Free Put, free Spd, PAs-fpm, free Tyr, and Tyr-fpm levels were higher in apparently healthy leaves than in healthy leaves. The PAs-mm levels were slightly affected by eutypiosis in apparently healthy leaves. The specific role of each type of polyamines and tyramine is discussed with regard to the host-parasite relationship.Key words: polyamines, leaf, Eutypa lata, Vitis vinifera.

I. Synthesis of aromatic monamines by intramolecular atomic interchange

In a paper submitted to the German Chemical Society about a year ago, we proved (Dr. Martius and myself) that the action of methylic alcohol on aniline chlorhydrate at a high temperature and under pressure, far from yielding exclusively methyl- and dimethylaniline, as had been formerly believed, is capable of causing methylation of the phenyl group, and thus producing quite a series of higher homologues of dimethylaniline. If we endeavour to gain an insight into the mechanism of this reaction, we are led to assume that in the first instance the chlorhydric acid of the aniline salt gives rise to the formation of methylic chloride, which in its turn induces substitution, first in the ammonia fragment, and ultimately in the phenyl group itself. If, on the other hand, we remember that a tertiary monamine, such as must be formed by the final methylation of the ammonia fragment in aniline, when submitted to the action of an alcohol chloride, is invariably converted into an ammonium compound, it must appear rather strange that, in the process above alluded to, only tertiary, and never any quartary bases are observed.

III. Contributions towards the history of the ethylene bases

The manufacture of chloral, which, since the discovery of the remarkable physiological properties of this compound, is conducted on a daily increasing scale, gives rise to a variety of secondary products which have not failed to attract the attention of chemists. Some time ago I showed that the most volatile fraction of these by-products consists almost entirely of chloride of ethyl, constituting a very valuable material for the preparation of an abundant quantity of the ethylated ammonias. The fraction boiling between 70° and 100° is chiefly bichloride of ethylene, which, when submitted to the action of alcoholic ammonia at 100°, furnishes a supply of ethylene bases such as would be difficult to obtain from other sources. Dr. Schering, one of the principal manufacturers of chloral in Berlin, has lately placed at my disposal between 30 and 40 kilograms of these latter by-products, which the kindness of my friends Drs. Martius and Mendelssohn, by placing at my disposal one of their magnificent enamelled autoclaves, has permitted me to treat in one single operation with alcoholic ammonia. The product of this operation was a large proportion of sal-ammoniac deposited in crystals, and a dark alcoholic mother-liquor which, after the alcohol had been distilled off, yielded on evaporation a brown crystalline residue, consisting of salts of ethylene bases. Large quantities of ethylenediamine chlorhydrate in a state of absolute purity were separated from this mixture by systematic crystallization. An additional portion was procured by distilling the mother-liquor, after it had ceased to crystallize, with an alkali, collecting apart the products, as long as they yielded with chlorhydric acid the easily crystallizable ethylenediamine salt. In this manner more than a kilogram of the perfectly pure chlorhydrate was obtained, not to speak of quantities of the more complex bases, which I have not yet endeavoured to separate.