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Lignans from Schisandra chinensis berries show various pharmacological activities, of which their antioxidative and cytoprotective properties are among the most studied ones. Here, the first report on antibacterial properties of six dibenzocyclooctadiene lignans found in Schisandra spp. is presented. The activity was shown on two related intracellular Gram-negative bacteria Chlamydia pneumoniae and Chlamydia trachomatis upon their infection in human epithelial cells. All six lignans inhibited C. pneumoniae inclusion formation and infectious progeny production. Schisandrin B inhibited C. pneumoniae inclusion formation even when administered 8 h post infection, indicating a target that occurs relatively late within the infection cycle. Upon infection, lignan-pretreated C. pneumoniae elementary bodies had impaired inclusion formation capacity. The presence and substitution pattern of methylenedioxy, methoxy and hydroxyl groups of the lignans had a profound impact on the antichlamydial activity. In addition our data suggest that the antichlamydial activity is not caused only by the antioxidative properties of the lignans. None of the compounds showed inhibition on seven other bacteria, suggesting a degree of selectivity of the antibacterial effect. Taken together, the data presented support a role of the studied lignans as interesting antichlamydial lead compounds.

Transgenic hairy roots of R. stricta were developed for investigation of alkaloid accumulations. The contents of five identified alkaloids, including serpentine as a new compound, increased compared to non-transformed roots. Rhazya stricta Decne. is a rich source of pharmacologically active terpenoid indole alkaloids (TIAs). In order to study TIA production and enable metabolic engineering, we established hairy root cultures of R. stricta by co-cultivating cotyledon, hypocotyl, leaf, and shoot explants with wild-type Agrobacterium rhizogenes strain LBA 9402 and A. rhizogenes carrying the pK2WG7-gusA binary vector. Hairy roots initiated from the leaf explants 2 to 8 weeks. Transformation was confirmed by polymerase chain reaction and in case of GUS clones with GUS staining assay. Transformation efficiency was 74 and 83% for wild-type and GUS hairy root clones, respectively. Alkaloid accumulation was monitored by HPLC, and identification was achieved by UPLC-MS analysis. The influence of light (16 h photoperiod versus total darkness) and media composition (modified Gamborg B5 medium versus Woody Plant Medium) on the production of TIAs were investigated. Compared to non-transformed roots, wild-type hairy roots accumulated significantly higher amounts of five alkaloids. GUS hairy roots contained higher amounts two of alkaloids compared to non-transformed roots. Light conditions had a marked effect on the accumulation of five alkaloids whereas the composition of media only affected the accumulation of two alkaloids. By successfully establishing R. stricta hairy root clones, the potential of transgenic hairy root systems in modulating TIA production was confirmed.

The results show that the present GC-MS method is reliable and well applicable for studying the variation of indole alkaloids in Rhazya samples.

A method was developed to measure the radicalscavenging activity of compounds separated by reversed-phase TLC (RP-TLC) using phenolic acids as model analytes. TLC separation was followed by dipping the plate in a 0.04% (wt/vol) solution of 1,1-diphenyl-2-picrylhydrazyl (DPPH) in methanol. The compounds possessing radical-scavenging activity were detected as bright yellow bands against a purple background. A video documentation system based on a CCD video camera was used for the detection and quantification of the activity. The developed RP-TLC-DPPH method was compared to the widely used spectrophotometric DPPH assay. The results obtained by the two methods correlated well, apart from syringic acid, ascorbic acid, and n-propyl gallate, which proved to be outliers in the regression analyses. The correlation coefficient, after excluding outliers, was r 2 = 0.923. The RP-TLC-DPPH method was applied for the measurement of free radical-scavenging activity of rapeseed meal fractions. A total of 10 separated zones with free radical-scavenging activity were detected, with R f values ranging from 0.04 to 0.85. The results show that the method can be used for the effective fractionation and analysis of potential antioxidative compounds in natural extracts.Paper no. J10222 in JAOCS 80, 9-14 (January 2003).KEY WORDS: 1,1-Diphenyl-2-picrylhydrazyl, free radical scavenging activity, phenolic compounds, reversed-phase thinlayer chromatography.The oxidation of lipids is the main mechanism responsible for the deterioration of food (1). The oxidation process can be prevented effectively by using free radical-scavenging antioxidants such as BHA, BHT, and propyl gallate. Furthermore, berries, fruits, and vegetables naturally contain many antioxidative compounds, for example, simple phenolics, flavonoids, and tannins. In addition to the conjugated diene method, which measures the rate of hydroperoxide formation and decomposition in different lipid systems and emulsions (2,3), radical-scavenging assays such as measurement of hydroxyl radical-scavenging activity, superoxide anion radical-scavenging activity, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity (4) have also been used.DPPH is a stable, water-soluble free radical with an absorption maximum at 517 nm (5). This strong absorption is due to the unpaired electron of the DPPH radical (4). When this radical compound accepts an electron or a hydrogen radical from a radical scavenger, the absorption vanishes and the resulting decolorization is stoichiometric with respect to the number of electrons taken up.Many variations of the spectrophotometric DPPH method, first developed by Blois (4), are currently used, and this method has attained the status of a routine procedure in the screening of antioxidants (6-10). These methods measure the total DPPH radical-scavenging activity of the extracts or fractions of interest but lack the ability to isolate the activity caused by only one or a few components of the mixture.TLC combined with DPPH radical detection of antioxida...

A method for the separation of parasorboside and gerberin from the ornamental plant Gerbera hybrida (Asteraceae) has been developed. The two closely related glucosides were extracted using an Extrachrom instrument, a prototype multi-functional separation tool equipped with an extraction chamber. The rotation planar extraction procedure was compared with that of a medium pressure solid-liquid extraction system. The resulting extracts were pre-purified using rotation planar chromatography and the results compared with those obtained using medium pressure liquid chromatography with silica gel as the stationary phase and a mobile phase of methanol:ethyl acetate:tetrahydrofuran at selectivity point Ps = 111 with 1% formic acid as modifier. The title compounds were isolated from the purified extracts by TLC and their structures confirmed by 1H- and 13C-NMR spectroscopy.

The coumarin composition of Peucedanum palustre (L.) Moench populations growing in Finland was investigated. A total of 132 flowering P. palustre specimens from 43 locations in southern and central Finland were collected, divided into root, stem, leaf, and umbel samples, and analyzed by HPLC. HPLC coupled to high-resolution mass spectrometry was used to aid the identification of coumarins. A total of 13 coumarin-structured compounds were quantitatively analyzed from the samples. The coumarin profile of root samples was found to differ from the aerial plant parts. The main coumarins in roots were oxypeucedanin and columbianadin. In aerial parts, peulustrin isomers were the most abundant coumarin components. Umbels and leaves also contained a considerable amount of umbelliprenin, which was only found in traces in roots. Based on hierarchical cluster analysis of the coumarin profiles, some populations shared common characteristics. The most distinct property connecting certain populations was their high peulustrin content. Another notable common property between some populations was the high umbelliprenin content in aerial plant parts. Some populations were clustered together due to their low overall coumarin content.