Volume 67, Issue 11-12

Acetone/water extracts from the leaves, including stalks, of Alchemilla vulgaris L. and A. mollis (Buser) Rothm. were investigated for their phenolic composition by liquid chromatography- tandem mass spectrometry (LC-MS/MS). A total of 24 and 27 compounds were detected for A. vulgaris and A. mollis, respectively. Pedunculagin and agrimoniin, as described in earlier reports for A. vulgaris, as well as other monomeric and oligomeric ellagitannins such as sanguiin H-10, castalagin/vescalagin, and galloyl-bis-hexahydroxydiphenoyl (HHDP) hexose constituted the major phenolic fraction of both plant species. Also, gallic and chlorogenic acids were found in both extracts. Interestingly, catechin and a procyanidin trimer were detected only in A. mollis. The fl avonoid fraction comprised quercetin glucuronide as major compound in addition to several other quercetin glycosides. Most interestingly, a tentatively identifi ed kaempferol glucuronide and a methylated quercetin glucuronide were exclusively found in A. mollis. Finally, the overall phenolic fingerprints of both Alchemilla species, harvested in May and August, i.e. at the beginning and the end of the flowering period, were compared. A general accumulation of phenolic constituents was observed later in the year, especially with regard to the ellagitannins.

Delphiniflexine, a new norditerpenoid alkaloid, together with the three known norditerpenoid alkaloids methyllycaconitine, ajadine, and acoseptrigenine were isolated from the aerial parts of Delphinium flexuosum. The structure of delphiniflexine was established on the basis of 1 H, 13 C, DEPT, homonuclear 1 H COSY, NOESY, HSQC, and HMBC NMR studies.

There is a great variation in the chemical composition of propolis of different origins. Likewise, the method of its extraction has signifi cant impact on the content of biologically active compounds. Here we compared methods of propolis extraction for optimal antioxidant activities which were measured by means of β-carotene discolouration, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, and 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS •+ ) radical cation decolouration assays. In the extracts, the contents of polyphenols and fl avonoids were measured, and phenolic acids were identifi ed and quantifi ed by HPLC. A three-step extraction allowed obtaining large amounts of phenolic acids from propolis. The propolis fractions obtained had antioxidant properties comparable to those of α-tocopherol and butylated hydroxytoluene. Therefore, they may be used as effective natural antioxidants.

Seven synthetic tetrahydroquinolines with different substitution patterns were obtained by an imino Diels-Alder condensation reaction and were evaluated against phytopathogenic fungi. Compounds with a methoxy group showed interesting activity against Cladosporium cladosporoides with a MIC value of 13.75 μg/mL

4-(α-L-Rhamnosyloxy)benzyl isothiocyanate (1) and 4-(4’-O-acetyl-α-L-rhamnosyloxy)- benzyl isothiocyanate (2) isolated from Moringa oleifera seeds were screened for their antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa, and for their antifungal activities against Candida albicans, Trichophyton rubrum, and Epidermophyton floccosum using the disk diffusion method. Isothiocyanates 1 and 2 were found active at the lowest inhibitory concentration of 1 mg/ml against all Grampositive bacteria tested (S. aureus, S. epidermidis, B. subtilis) and against the dermatophytic fungi E. floccosum and T. rubrum. Statistically signifi cant differences were found between the mean inhibition zones (IZ) of 1 and 2 and the standard drugs, ofl oxacin and clotrimazole. The minimum inhibitory concentration (MIC) values confi rmed the good antimicrobial activity of 1 and 2 against S. aureus, good to moderate activity against S. epidermidis, moderate activity against B. subtilis, and weak activity against E. floccosum and T. rubrum. The in vitro bactericidal effect of 1 and 2 against the Gram-positive bacterial strains tested is suggested by MBC:MIC ratios of 2:1.

A study of the components of Paris quadrifolia was undertaken to identify compounds with potential influence on cardiac cells, since previous reports suggested a cardiotoxic risk of this plant. Compounds isolated and identified included one new steroidal saponin, (23S,24S)- spirosta-5,25(27)-diene-1β,3β,21,23,24-pentol-1-O-β- D -apiofuranosyl-(1→3)-α-L-rhamnopyranosyl-( 1→2)-[β- D -xylopyranosyl-(1→3)]-β- D -glucopyranoside 21- O- β- D - apiofuranoside 24-O-β- D -fucopyranoside (1), demonstrating quite unusual structural features, as well as the known compounds 26-O-β- D -glucopyranosyl-(25R)-5-en-furost-3β,17α,22α,26-tetraol- 3- O- α- L - rhamnopyranosyl-(1→4)-α- L -rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl - -(1→2)]- β- D - glucopyranoside (2), pennogenin 3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamno pyranosyl- (1→4)-[α-L-rhamnopyranosyl-(1→ 2)]-β - D - glucopyranoside (3), 7- O- β- D -glucopyranosyl- kaempferol-3- O- β- D -glucopyranosyl-(1→2)-β- D -galactopyranoside (4), kaem pferol- 3-O-β- D -glucopyranosyl-(1→2)-β- D -galactopyranoside (5), 5-hydroxyecdysterone (6), and 20-hydroxyecdysone (7). The pennogenin derivative 3 showed strong cardiotoxic effects in an in vitro cellular model system, whereas the respective furostanol derivative 2 was inactive.

Hydrodistilled oils of the fresh aerial parts of Mentha suaveolens Ehrh. cultivated in Egypt were prepared from samples collected along the four seasons. The percentage yields of these essential oils were 0.50%, 0.52%, 0.60%, and 0.47% of the dry weight for winter, spring, summer, and autumn samples. GC/MS analyses of all samples revealed a qualitative and quantitative variability in the oil composition. The total number of compounds identified was 46 among which 15 were common in all samples. The oxygenated compounds constituted about 45%, 46%, 63%, and 44% of the total composition of the oils for winter, spring, summer, and autumn samples, respectively. Carvone was the major constituent in spring, summer, and autumn samples (about 31%, 56%, and 35%, respectively), while limonene (ca. 26%) was the major constituent of the winter sample followed by carvone (ca. 25%). The essential oil of the highest yield (full-fl owering summer sample), with the highest oxygenated constituents and carvone contents, was screened for certain biological activities. It exhibited analgesic and acute anti-inflammatory activities (75% and 82% relative to indomethacin). It also showed a potent in vivo antioxidant activity (96% relative to vitamin E). In addition, it exerted moderate cytotoxic, hepatoprotective, and in vitro antioxidant activities. Moreover, the oil had a potent antifungal activity against Candida albicans (MIC = 4 μg/ml), Saccharomyces cerevisiae (MIC = 5.2 μg/ml), and Aspergillus niger (MIC = 6.8 μg/ml).

Phytochemical investigations of the methanolic extract of the fruits of Peucedanum grande C. B. Clarke (Apiaceae) led to the identification of three coumarins and a naphthyl labdanoate diarabinoside characterized as 5-hydroxy-6-isopranyl coumarin (1), 5,6-furanocoumarin (2), 7-methoxy-5,6-furanocoumarin (3), and labdanyl-3 α -ol-18-(3’’’-methoxy-2’’’- naphthyl-oate)-3 α-L -arabinofuranosyl-(2’→1’’)- α-L -arabinofuranoside (4). The structures of these compounds were identified on the basis of spectral data analysis and chemical reactions. The methanolic extract and 4 showed nephroprotective activity against gentamicininduced nephrotoxicity in Wistar rats.

Aspyran (1), a novel compound, and the known isocoumarin asperentin (2), also known as cladosporin, together with its analogues 3 - 6 were isolated from Aspergillus sp. and their structures established by spectroscopic methods including 2D NMR spectroscopy. The effects of 1 - 6 on plant growth were examined by bioassays using lettuce and rice seedlings. Compounds 1 and 3 promoted the root growth of the seedlings, while 2 and 5 were inhibitory. Compounds 4 and 6 did not show any effect on the growth of lettuce and rice seedlings, respectively.

Selenium is an essential nutrient with diverse physiological functions, and soluble organic selenium (SOS) sources have a higher bioavailability than inorganic selenium sources. Based on the response surface methodology and central composite design, this study presents the optimal medium components for SOS accumulation in batch cultures of Flammulina velutipes, i.e. 30 g/L glucose, 11.2 mg/L sodium selenite, and 1.85 g/L NH 4 NO 3 . Furthermore, logistic function model feeding was found to be the optimal feeding strategy for SOS accumulation during Flammulina velutipes mycelia fermentation, where the maximum SOS accumulation reached (4.63 ± 0.24) mg/L, which is consistent with the predicted value.

A protocol for the efficient genetic transformation of licorice (Glycyrrhiza inflata Batalin) cells in suspension culture using Agrobacterium tumefaciens-mediated T-DNA delivery is described. G. inflata cells in suspension culture were infected with A. tumefaciens strain LBA4404 harbouring the binary vector pCAMBIA1303, which contains the β-glucuronidase (GUS) reporter gene and a hygromycin resistance gene (hpt II), respectively, under the transcriptional control of the CaMV35S promoter. Optimal transformation effi ciency was achieved with an A. tumefaciens suspension having an OD 600 of 0.4 and a period of 24 h of co-cultivation with 3-day-old cells in a medium supplemented with 200 μM acetosyringone. The transgenic cell lines have been maintained in suspension subculture for 5 months. PCR and Southern blot analyses confirmed the stable integration of transgenes into the G. inflata genome. The introduced genes had no discernable effect on cell growth or accumulation of total licorice fl avonoids in the transgenic cell lines. This study provides the basis for the development of transgenic G. inflata cells.

Genes coding for avenin-like proteins (ALP) represent a new family of wheat storage protein genes. To find a wheat endosperm-specific promoter, a 1644-bp fragment upstream of the ALP type-B gene (GenBank accession number JN622144) was isolated. The important promoter elements of the ALP type-B gene were ascertained through sequence analysis which revealed that this fragment contains the TATA and CAAT boxes, which are important elements in gene expression. A prolamin box containing an endosperm motif and a GCN4-like motif (GLM) is present at about 300 bp upstream of the translation start site. The promoter sequence has two ESP-like elements and one of them is followed by an RY motif with the nucleotides CATG overlapping. The RY motif is considered the core functional sequence in a promoter. In an attempt to confirm the promoter activity, a series of 5¢-deletions of the promoter were fused with the β-glucuronidase (GUS) gene, and the constructs were stably introduced into tobacco plants. GUS staining confirmed that the AVL type-B promoter is an endosperm-specific promoter in tobacco seeds. Quantitative analysis of GUS expression in transgenic plants showed that even the shortest 5’-deletion, i.e. a 290-bp promoter sequence within the prolamin box, was sufficient to drive GUS expression in the endosperm. The highest expression level was found in transgenic plants containing the 5¢-deletion vector construct pALP-8. This suggests that the ESP-like element overlapping with the RY motif may play a crucial role in the regulatory function of the promoter.

Blue-green algae (cyanobacteria) constitute the greater part of the phytoplankton. Microcystis aeruginosa is amongst the most ubiquitously distributed cyanobacterial species, and almost invariably produces cyclic heptapeptide toxins called microcystins (MCs). The present study was designed to investigate the phenological and liver antioxidant profiles of the Nile tilapia Oreochromis niloticus chronically exposed to toxic live M. aeruginosa cells. Fish were grown in the absence and presence of M. aeruginosa in three different concentrations for seven days, and subsequently reared for another 30 days in the absence of the cyanobacteria. While cyanobacteria did not cause any fish mortality, there was a progressive development of yellowish discolouration in the livers of exposed fish. In the livers, the activities and levels of superoxide dismutase (SOD), lactate dehydrogenase (LDH), glutathione (GSH), and lipid peroxidation products like malondialdehyde (MDA) were elevated in response to the concentration of M. aeruginosa. Moreover, DNA fragmentation and DNA-protein crosslinks were measured. These parameters can thus be considered potential biomarkers for the fish exposure to M. aeruginosa. The present study sheds light on cyanobacterial blooms like health, environmental, and economic problem, respectively.