Agladze Inorganic Chemistry and Electrochemistry

ABSTRACT Most of pharmaceutical agents display several or even many biological activities. It is obvious that testing even one compound for thousands of biological activities is a practically not reasonable task. Therefore, computer-aided prediction is the method of choice for the selection of the most promising bioassays for particular compounds. Using PASS Online software, we determined the probable antimicrobial activity of the 31 steroid derivatives. Experimental testing of the antimicrobial activity of the tested compounds by microdilution method confirmed the computational predictions. Furthermore, P. aeruginosa and C. albicans biofilm formation was investigated. Compound 11 showed a biofilm reduction by 42.26% at the MIC of the tested compound. The percentages are lower than ketoconazole, but very close to its activity.

The internal structure of leaf of the F. japonica that is introduced in Georgia as a source of biologically active substances, was studied, and its microstructural diagnostic signs were determined. F. japonica leaf glabrous, bilateral, dorsoventral, hypostomatic structure. The basal cells of the abaxial and adaxial epidermis of the leaf are non-stitched, curvilinear and curved-walled, the cuticular mosaic of the lower epidermis is wavy. The stomatal apparatus of the Japanese fatsia leaf is anisocytic, the stomatal gap is fusiform, and the location of the stomata is chaotic. A reverse-collateral conductive bundle is imprinted in the pulp of the leaf. In the structural units of all morphological organs of the plant leaf, differentiation of calcium oxalate druse crystals and secretory cells is noticeable. The tissue of the main vein of the leaf of F. japonica is polygonal, the conducting system both in the vein and in the petiole is of fibro-vascular, open-collateral type, but in the main vein bundles are asymmetrical, while in the petiole they are symmetrical and closely interconnected. The  xylem of the main vein and petiole of F. japonica leaf’s has differentiated bulbs arranged in longitudinal rows. Xylem conductive vessels with spiral, ring and mesh thickenings of the shell are observed lengthwise the petiole.

Three sesquiterpene glycosides, i.e., nerolidol derivatives, and steroidal glycosides of the 3-furostanol and 1-spirostanol series, one of which was new and characterized as (25R)-26-O-β-D-Glcp-5α-furostan-3β,22α,26-triol 3-O-β-D-Xylp-(1→3)-[O-β-D-Glcp-(1→3)-O-β-D-Glcp-(1→2)]-O-β-D-Glcp-(1→4)-O-β- D-Galp, were isolated from flowers of Yucca elephantipes Regel cultivated in Georgia. The structures of the glycosides were elucidated using one- and two-dimensional NMR (1H, 13C, HSQC, HMBC, COSY) and mass spectrometry (ESI-MS).

Three sesquiterpene glycosides were isolated from the MeOH (70%) extract of flowers of Yucca gloriosa L. Their chemical structures were established using spectral analyses, i.e., 1D and 2D NMR (1H, 13C, HSQC, HMBC, COSY) and mass spectroscopy (ESI-MS). They all were new glycoside derivatives of nerolidol and a new class for the genus Yucca. Glycoside 1 had the structure (1E,3S,5R,6E,9E)-5-O-β-D-glucopyranosyl-(1_6)-O-β-D-glucopyranosyl-3,5,11-trihydroxy-3,7,11-trimethyldodeca-1,6,9-triene; glycoside 2, (1E,3S,5R,6E,9E)-5-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl-3,5,11,12-tetrahydroxy-3,7,11-trimethyldodeca-1,6,9-triene; glycoside 3, (1E,3S,5R,6E,10E)-(12-O-β-D-glucopyranosyl)-5-O-β-Dglucopyranosyl-(1→6)-O-β-D-glucopyranosyl-3,5,12-trihydroxy-3,7,11-trimethyldodeca-1,6,10-triene.

The megastigmane glycosides roseoside and debiloside B; a new compound with the established structure (3R,4R,7E,9R)-5,7-megastigmadien-3,4,9-triol 9-O-β-D-glucopyranoside, which was named vajicoside; and the new phenolic compound 2-O-sulfo-β-D-glucopyranoside were isolated from leaves of Tribulus terrestris growing in Georgia.

Three new phenylethanoid glycosides, named digicilisides A – C (1 – 3, resp.), have been isolated from the roots of Digitalis ciliata, along with five known phenylethanoid glycosides. The structures of 1 – 3 were identified as 2-(4-hydroxy-3-methoxyphenyl)ethyl β-d-glucopyranosyl-(1→3)-[α-l-rhamnopyranosyl-(1→6)]-4-O-[(E)-feruloyl]-β-d-glucopyranoside (1), 2-(3,4-dihydroxyphenyl)ethyl α-l-arabinopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→3)]-[α-l-rhamnopyranosyl-(1→6)]-4-O-[(E)-feruloyl]-β-d-glucopyranoside (2), and 2-(3,4-dihydroxyphenyl)ethyl β-d-glucopyranosyl-(1→3)-{6-O-[(E)-feruloyl]-β-d-glucopyranosyl-(1→6)}-4-O-[(E)-caffeoyl]-β-d-glucopyranoside (3).

A reliable HPLC method coupled with DAD detection was developed and validated for determination of majdine in Vinca herbacea. The chromatographic separation was carried out on a Symmetry C18 column (250 mm x 4.6 mm, 5 microm, Waters) with an isocratic solvent system of 25 mM potassium phosphate buffer (pH = 3.0)-acetonitrile. UV detection was performed at 225 nm. Good linear behavior over the investigated concentration range was observed with the value of r2 > 0.9978. The method was reproducible with intra- and inter-day variations of less than 4.38%. The proposed method was linear, accurate, precise and specific. The validated method was successfully applied to quantify majdine in various parts of V. herbacea, which was collected during the flowering months of April and May. The results indicated that the developed HPLC method could be used for the quality control of V. herbacea and for the standardization of its extracts in majdine.