Evaluation of Electronic Spectra of Unsaturated Organic Compounds Using the Pariser-Parr-Pople Method with Adaptation of Parameters

The possibility of quantitative predictions of absorption maxima in electronic spectra of unsaturated organic compounds by means of the Pariser-Parr-Pople method with adaptation of parameters is examined. A schematic classification of quantum chemical methods is proposed which is based on the idea of extrapolation from elementary particles (physical constants) to the molecule, from atoms to the molecule and, finally, from fragments to the molecule

Oxidation and Homolytic Coupling Regioselectivity of Carbazole in Acidie Media

Using voltammetric technique with a rotating disk electrode, the anodic oxidation of carbazole in aqueous H2S04 - ethanol mixtures was shown to proceed under diffusion and electron transfer control conditions. Electro-oxidation involves one electron transfer; electrode passivation occurs due to the formation of a poorly soluble product. By means of the SCF MO LCAO INDO, AMI-UHF and PM3-UHF methods, oxidative coupling regioselectivity for carbazole has been elucidated. Chemical oxidation of carbazole by ammonium vanadate in sulphuric acid medium features the stoichiometry 1:2, first order in substrate and first order in oxidant, and leads to the occurrenee of the diimine dication of carbazole

Biotehnološka primjena gljive Lentinula edodes – od lentinana do lektina

Lentinula edodes was the first medicinal macrofungus to enter the realm of modern biotechnology. The present paper briefly reviews the history of the modern biotechnology of this mushroom starting with the production of the polysaccharide preparation lentinan, and ending with an overview of our own work regarding the production of lectins. Our work with lectins has involved studies of the effect of initial pH, carbon and nitrogen sources and the C:N ratio on lectin production in both the mycelium and culture medium. We have shown that lectin activity is related to morphological development, with the activity being highest in extracts of the pigmented mycelial films that precede fruiting body production.Lentinula edodes prva je medicinska gljiva koja se počela primjenjivati u suvremenoj biotehnologiji. U ovom se radu nalazi kratak pregled razvoja suvremene biotehnološke primjene te gljive, počevši od proizvodnje polisaharida lentinana pa sve do prikaza rezultata autora u proizvodnji lektina. Njihovo istraživanje obuhvaća ispitivanje učinka početne pH-vrijednosti, izvora ugljika i dušika te njihova omjera na nastanak lektina u podlozi za uzgoj micelija i kulture. Dokazano je da je aktivnost lektina povezana s morfološkim razvojem, te da je najveća u ekstraktima pigmentiranoga micelijskog filma koji prethodi nastanku plodišta

Biotehnološka primjena gljive Lentinula edodes – od lentinana do lektina

Lentinula edodes was the first medicinal macrofungus to enter the realm of modern biotechnology. The present paper briefly reviews the history of the modern biotechnology of this mushroom starting with the production of the polysaccharide preparation lentinan, and ending with an overview of our own work regarding the production of lectins. Our work with lectins has involved studies of the effect of initial pH, carbon and nitrogen sources and the C:N ratio on lectin production in both the mycelium and culture medium. We have shown that lectin activity is related to morphological development, with the activity being highest in extracts of the pigmented mycelial films that precede fruiting body production.Lentinula edodes prva je medicinska gljiva koja se počela primjenjivati u suvremenoj biotehnologiji. U ovom se radu nalazi kratak pregled razvoja suvremene biotehnološke primjene te gljive, počevši od proizvodnje polisaharida lentinana pa sve do prikaza rezultata autora u proizvodnji lektina. Njihovo istraživanje obuhvaća ispitivanje učinka početne pH-vrijednosti, izvora ugljika i dušika te njihova omjera na nastanak lektina u podlozi za uzgoj micelija i kulture. Dokazano je da je aktivnost lektina povezana s morfološkim razvojem, te da je najveća u ekstraktima pigmentiranoga micelijskog filma koji prethodi nastanku plodišta

Effect of Media Components on the Mycelial Film Formation in Submerged Culture of Lentinus edodes (Shiitake)

A relationship between the chemical composition of nutrient medium, the activity of extracellular lectins of Lentinus edodes (Berk.) Sing Lentinula edodes (Berk.) Pegler (shiitake), and the formation of pigmented mycelial film in liquid culture has been found. A possibility to regulate the lectin activity of shiitake using the synthetic components has been shown. The formulation of medium, on which the brown mycelial film appears in several days of submerged cultivation, has been proposed. Among the natural amino acids studied as nitrogen sources, and nine divalent metal cations as inorganic additives, L-asparagine and Ca2+ (Mn2+) in the simultaneous presence exhibited the explicit positive effect in respect to the above without regard to the age of the culture. Quantum chemical methods and QSAR were applied to test our supposition that a differential character of interaction between the studied amino acids and Ca2+ (Mn2+) cations should be related not to the distinct electron structures of zwitter ions, but most likely to their differing hydrophobicities. The results obtained seem to make some contribution to the present notion of biochemicalprocesses that give rise to the occurrence of the aforesaid morphological structure of shiitake

Use of semiempirical quantum chemical approaches in computation of molecular dipole moments of tropones and tropolones

Using the MNDO, AM1 and PM3 methods, the dipole moments (µ) of 28 tropones and 34 tropolones molecules have been computed. The potentials of the above approaches for the evaluation of m have been revealed. The correlations µexper = bµtheor have been established

Original scientific paper Thermodynamic properties of cadmium compounds from

By the PM3 method, standard entropies, heats and free energies of formation for some cadmium compounds have been computed. Quantitative relationships P exper vs, P theor, where P is any of the mentioned properties, have been established

Original scientific paper Electronic structure of planar-quasicycled organic molecules with intramolecular hydrogen bond

Abstract: By means of the HF/6-311G(d,p) method, the electronic structure of the series of organic molecules, among which are malonaldehyde, acetylacetone, thiomalonaldehyde, the derivatives of aniline 2-XC6H4NH2, phenol 2-XC6H4OH, benzenethiol 2-XC6H4SH (X = CHO, COOH, COO-, NO, NO2, OH, OCH3,SH,SCH3,F,Cl, Br), 8-hydroxyquinoline, 8-mercaptoquinoline, tropolone, has been studied. The intramolecular hydrogen bond (IHB) has been established to lead to a local electron redistribution in quasicycle, and primarily to the electron density transfer between the direct IHB participants – from the hydrogen atom toward the proton-aceptor atom. On forming the IHB of the S–H···O type, the electron density in general decreases on the sulphohydryl hydrogen atom and increases on the sulphur atom

JSCS–3545 Original scientific paper

Evaluation of the intramolecular hydrogen bond enthalpy by means of specialized quantum chemical method