[Structural traits of the antioxidant and fungicidal activity of steroid glycosides]. / Strukturnye priznaki antioksidantnoi i fungitsidnoi aktivnosti steroidnykh glikozidov.

To investigate the origin of antioxidant and antifungal properties of steroid glycosides (SG), a logico-structural analysis of the structure-activity relationships has been performed for 70 compounds using a set of computer programs STRAC. The following structural features responsible for antioxidant activity are revealed: 1) furostanol type of aglycon; 2) the presence of more than 4 branched monosaccharides in the carbohydrate chain; 3) the presence of glucose at C26 and OH-groups in the genin part of SG. Most characteristic for antifungal activity is the fragment genin-C3-Gal-Glc-Glc-Rha..., as well as the spirostanol type of aglycon. The computer analysis provided the basis for predicting a type of biological activity for 12 new compounds of the SG class.

Structure-odour relationships: results of an applied electron-topological approach.

Relationships between odour and chemical structure of compounds are studied by means of the electron-topological method developed for structure/activity research especially. A brief explanation is given for distinguished features of the method. Application examples are demonstrated for sandalwood, ambergris odour, garlic aroma and meat keynotes in food additives. The structural fragments affecting the odour appearance are revealed and discussed with respect to their electronic and topological peculiarities. The latter are formulated as rules for activity prediction of new compounds with special properties.

Study of the relationship between chemical structure and antimicrobial activity in a series of hydrazine-based coordination compounds.

The dependence of antimicrobial activity on the structure of compounds is studied in a series of compounds based on hydrazine coordinated with ions of Cu(II), Ni(II) and Pd(II). The study has been carried out by means of the original electron-topological method developed earlier. A molecular fragment has been found that is only characteristic of biologically active compounds. Its spatial and electron parameters have been used for the quantitative assessment of the activity in view. The results obtained can be used for the antimicrobial activity prediction in a series of compounds with similar structures.

Electron-topological investigation of the structure-antitumor activity relationship of thiosemicarbazone derivatives.

In the frameworks of the electron-topological method (ETM) the structure-antitumor activity relationship was investigated for a series of thiosemicarbazone derivatives. The series included 70 compounds. Conformational analysis and quantum-chemical calculations were carried out for each compound. The revealed activity feature showed a satisfactory description of the class of active compounds according to two different parameters P and alpha estimating the probabilities of the feature realization in the class of active compounds (they are equal to 0.94 and 0.86, correspondingly). The results of testing demonstrated the high ability of ETM in predicting the activity investigated.

Electron-topological investigation of structure-antitubercular activity relationship of thiosemicarbazone derivatives.

Within the framework of the electron-topological approach the structure-antitubercular activity relationship was investigated in a series of thiosemicarbazone derivatives. The series in view included 71 compounds. For each compound conformational and quantum-chemical calculations were carried out. An activity feature gave a satisfactory description of the class of active compounds: two parameters, alpha a and Pa, estimating the probabilities of its realization had the values equal to 0.935 and 0.914, correspondingly. At the same time the feature of inactivity found ("the break of activity") was realized within the class of inactive compounds with the probabilities alpha b = 0.749 and Pb = 0.950. Eight compounds not included in the teaching sample were tested for features presence. The results of the test demonstrated a high ability of the electron-topological method to predict the activity needed.

Structural and electronic origin of meat odour of organic hetero-atomic compounds.

By means of the electron-topologic approach suggested earlier, the structural and electronic features favouring meat odour occurrence are evaluated using 77 organic compounds with known odorant properties as a basis for primary logico-structural analysis. A general fragment of the type XH2 (where X = S, O, N is a hetero-atom) with a certain electronic structure and conformational property is shown to be responsible for the meat odour. The results obtained allow for a prognosis of odorant compounds and their purposeful synthesis.