Mincho E. Anchev

Triterpene saponins and iridoid glucosides from Galium rivale

Three new glycosides of the oleanene-type triterpenes, rivalosides C-E (1-3), along with three known triterpene saponins, momordin IIb (4) and rivalosides A-B (5-6), and five known iridoid glucosides: monotropein, scandoside, deacetylasperulosidic acid, geniposidic acid and asperulosidic acid, were isolated from aerial parts of Galium rivale. The structures of the new compounds were elucidated by spectral methods and chemical means as 2alpha-acetoxy-3alpha, 19alpha-dihydroxy-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl-(1--> 6)-beta-D-glucopyranoside, 2alpha,3alpha, 19alpha-trihydroxy-olean- 12-en-28-oic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside and 3-O-beta-D-glucuronopyranosyl-24-hydroxy-olean-12-en-28-oic acid 28-O-beta-D-glucopyranoside, for rivalosides C-E, respectively. The taxonomic significance of the rivalosides in G. rivale was discussed.

Infraspecific differentiation in the Balkan diploidCardamine acris (Brassicaceae): Molecular and morphological evidence

Molecular and morphological variation in the Balkan diploidCardamine acris was studied by amplified fragment length polymorphism (AFLP) and multivariate morphometric analyses. Principal coordinate analysis and neighbour-joining analysis of the AFLP data showed three genetically differentiated groups of populations corresponding to their geographic origin. Following the results of molecular analysis three subspecies were recognized by a combination of morphological characters as shown by separate analyses of field-collected and cultivated plants. These subspecies are allopatric;C. acris subsp.acris occurs in most parts of the Balkan Peninsula, and newly described subsp.pindicola and subsp.vardousiae are endemic to the Northern Pindhos Mts. in Northwestern Greece, and Central Greece, respectively. The differentiation into geographically isolated subspecies is most probably caused by long-term isolation of populations in different mountain ranges of the Balkan Peninsula, possibly initiated during the cold periods of the Pleistocene.

Iridoid patterns in Galium L. and some phylogenetic considerations.

From 19 species of Galium, members of 6 European sections of the genus, 24 compounds were isolated, namely 16 iridoid glucosides, 2 secoiridoid glucosides and 6 triterpene saponins (the later found only in G. rivale (Sibth. & Sm. Griseb.) The iridoid content was analyzed by thin layer chromatography - densitometry. An effort was made to clarify interspecies relationships, based on the obtained results and previous data. Generally, a nearly uniform iridoid pattern in the studied species was observed. Nevertheless, some distinctions gave reason the following chemical characters to be treated as taxonomic markers: iridoids, secogalioside (characteristic of G. mollugo group), iridoids V1 and V2 (G. humifusum Bieb. and G. verum L.), 6-acetylscandoside (G. incurvum group and G. verum) and the triterpene saponins, rivalioside A and rivalioside C (characteristic of G. rivale). The studied species regarding to the iridoids could be attributed to three lines of evolutionary differentiation. One line is leading to the differentiation of G. rivale. It contains specific triterpenoids as well as iridoid acids, which show parallel development of both glyceraldehyde 3-phosphate/pyruvate and mevalonate biosynthetic routes in this species. A second line includes G. mollugo and G. incurvum species groups and the species G. humifusum and G. verum. Variety of iridoid esters, hydroxy and carboxy derivatives of iridoids and secoiridoids characterised this line. Third line comprises the remaining studied species, members of different sections and species groups. They posses a nearly identical iridoid pattern, which suggests a convergent evolution regarding to the iridoids

IRIDOID GLUCOSIDES FROM GALIUM HUMIFUSUM BIEB

Abstract Galium humifusum, R ubiaceae, Iridoid G lycosides Two new iridoid glucosides, hum ifusin A and hum ifusin B, with a 3-(4-hydroxyphenyl)-p ropionate ester unit were isolated from Galium hum ifusum to g eth er with 11 know n iridoid glucosides asperuloside, scandoside, desacetylasperulosidic acid, asperulosidic acid, genipo-sidic acid, desacetylasperuloside. m onotropein, V I, V2, V3 and daphylloside. The new iri-doids w ere identified on the basis of spectral d ata. 13C N M R d ata for V I and V2 iridoids are reported.

TheRorippa pyrenaica group (Brassicaceae) in the Balkan Peninsula

TheRorippa pyrenaica group is represented in the area of Balkan Peninsula byR. pyrenaica (diploid),R. lippizensis (diploid), andR. thracica (diploid and tetraploid). They differ morphologically from all other EuropeanRorippa species by their pitted reticulate seed surface.Rorippa pyrenaica is characterized by ovoid elipsoidal siliculae, up to three times shorter than pedicels.Rorippa thracica andR. lippizensis possess linear siliquae, equal or longer than pedicels, they differ in length of fruits and length of petals. For all three species full synonymy, geographical distribution, ecological characteristics and karyotype data are provided.

Indoid Glucosides from Four Balkan Endemics of the Galium incurvum Group (Rubiaceae)

Abstract The Balkan endemics G. mirum, Galium macedonicum, G. rhodopeum and G. aegeum, from the G. incurvum group, were screened for iridoid glucosides. Eleven known iridoid glucosides were isolated, identified and analysed for the first time in the investigated plants. The main components appeared to be asperuloside and/or the non-acetylated iridoid acids -deacetylasperulosidic acid, scandoside, monotropein. Phylogenetic relationships are discussed.