HPLC, NMR Based Characterization, Antioxidant and Anticancer Activities of Chemical Constituents from Therapeutically Active Fungal Endophytes.

Fungi generate different metabolites some of which are intrinsically bioactive and could therefore serve as templates for drug development. In the current study, six endophytic fungi namely , , , , , and were isolated and identified from the medicinal plant, . These endophytic fungi were identified through intra transcribed sequence (ITS) gene sequencing.

New cytochalasans from an endophytic species associated with Costa Rican (Rubiaceae).

Four new leucine-derived cytochalasans, possessing a 5,6,5,8-ring () and a 5,6,11-ring core (-), were isolated from a cultivated endophytic fungus sp. strain WH2D4 (Xylariaceae). This fungus was isolated from leaves of the neotropical tree species (Sw.

Chemodiversity of tryptamine-derived alkaloids in six Costa Rican Palicourea species (Rubiaceae-Palicoureeae).

We report 14 harmala and tryptamine-iridoid alkaloids with various tri-, tetra- and pentacyclic cores from leaves and stem bark of six species of the large and complex neotropical genus Palicourea. Among them is the previously undescribed compound deoxostrictosamide which is related to strictosamide, a key intermediate in camptothecin biosynthesis. In addition, we describe the occurrence of 1,2,3,4-tetrahydronorharman-1-one for the first time within Rubiaceae and ophiorine A and B, two alkaloids with an unusual core bearing a betaine function and a zwitterion as new for the genus.

Striking Diversification of Exudate Profiles in Selected Primula Lineages.

In continuation of previous studies on glandular exudates of Primula, we analyzed eleven so far unstudied species and several populations for exudate composition. Unsubstituted flavone and unusually substituted flavones, normally predominant in Primula exudates, were not detected in all of the analyzed samples. Instead, some species exhibited regular substituted flavonoids, and in some cases, no flavonoids could be detected at all.

Orphan flavonoids and dihydrochalcones from Primula exudates.

Two orphan flavonoids containing an oxepin structure in ring A and named as Primcortusin (1) and 3'-OH-Primcortusin (2) were isolated from leaf exudates of Primula cortusoides, while P. glutinosa exudates yielded two dihydrochalcone derivatives (3,4). These novel structures have not been detected in other species of Primula so far.

Flavonoids in selected Primula spp.: bridging micromorphology with chemodiversity.

A combined study was carried out on the micromorphology and chemistry of glandular trichomes with focus on Primula vialii and P. vulgaris, respectively. Epifluorescence microscopy was applied to study the auto-fluorescent properties of flavonoids and their localization in glandular trichomes.

Diversification of exudate flavonoid profiles in further Primula spp.

In continuation of previous work, exudate flavonoid profiles of 22 new accessions of the genus Primula L. aligned to different subgenera were studied for the first time. Profiling was done by comparative TLC and UV-HPLC against authentic marker compounds.

Iridoids as chemical markers of false ipecac (Ronabea emetica), a previously confused medicinal plant.

Ethnopharmacological Relevance: Several roots or rhizomes of rubiaceous species are reportedly used as the emetic and antiamoebic drug ipecac. True ipecac (Carapichea ipecacuanha) is chemically well characterized, in contrast to striated or false ipecac derived from the rhizomes of Ronabea emetica (syn. Psychotria emetica).

Unusual compounds from exudates of Dionysia diapensifolia and D. gaubae var. megalantha (Primulaceae).

Exudates of Dionysia diapensifolia yielded (R)-(+)-3-acetoxy-3-phenyl-propiophenone as a new natural product with a basic dihydrochalcone structure, which was elucidated unequivocally by mass spectrometry and NMR spectroscopy. The sesquiterpenoidcarissone was found as the major compound in the exudate of D. gaubae var.

Xanthones, biflavanones and triterpenes from Pentadesma grandifolia (Clusiaceae): structural determination and bioactivity.

Stem bark, roots, leaves and fruits of Pentadesma grandifolia Baker f. (Clusiaceae) have been analyzed for the presence of xanthones, biflavonoids and triterpenoids. Isolated and identified structures include the xanthones cowagarcinone B (1) and alpha-mangostin (2), further the two biflavanones 3,8"-binaringenin (3) and the corresponding 3,6"-binaringenin (4), which is here reported as natural constituent for the first time.

Chemodiversity of exudate flavonoids in Dionysia (Primulaceae): a comparative study.

More than 60 accessions of various Dionysia spp. were analysed for their exudate flavonoid composition. Many Dionysia spp.

Exudate flavonoids of Primula spp: structural and biogenetic chemodiversity.

Several new accessions of the genus Primula and of the closely related Cortusa matthioli have been studied for their exudate flavonoid profiles. Unsubstituted flavone, 5-hydroxy-, 2'-hydroxyflavone and 5,2'-dihydroxyflavone were found as main components. Several other rather unusual substitution patterns were also found.

Chemodiversity of exudate flavonoids in seven tribes of Cichorioideae and Asteroideae (Asteraceae).

Members of several genera of Asteraceae, belonging to the tribes Mutisieae, Cardueae, Lactuceae (all subfamily Cichorioideae), and of Astereae, Senecioneae, Helenieae and Heliantheae (all subfamily Asteroideae) have been analyzed for chemodiversity of their exudate flavonoid profiles. The majority of structures found were flavones and flavonols, sometimes with 6- and/or 8-substitution, and with a varying degree of oxidation and methylation. Flavanones were observed in exudates of some genera, and, in some cases, also flavonol- and flavone glycosides were detected.

Chemodiversity of surface flavonoids in Solanaceae.

Several species of Nicotiana and Solanum and further members of the Solanaceae have been examined for their exudate flavonoids. Most of the aglycones are widespread flavonols, but rare and unusual flavonols were also found, e.g.