Candidate egg case silk genes for the spider Argiope argentata from differential gene expression analyses.

Orb-web weaving spiders produce a variety of task-specific silks from specialized silk glands. The genetics underlying the synthesis of specific silk types are largely unknown, and transcriptome analysis could be a powerful approach for identifying candidate genes. However, de novo assembly and expression profiling of silk glands with RNA-sequencing (RNAseq) are problematic because the few known gene transcripts for silk proteins are extremely long and highly repetitive. To identify candidate genes for tubuliform (egg case) silk synthesis by the orb-weaver Argiope argentata (Araneidae), we estimated transcript abundance using two sequencing methods: RNAseq reads from throughout the length of mRNA molecules, and 3' digital gene expression reads from the 3' region of mRNA molecules. Both analyses identified similar sets of genes as differentially expressed when comparing tubuliform and nonsilk gland tissue. However, incompletely assembled silk gene transcripts were identified as differentially expressed because of RNAseq read alignments to highly repetitive regions, confounding interpretation of RNAseq results. Homologues of egg case silk protein (ECP) genes were upregulated in tubuliform glands. This discovery is the first description of ECP homologues in an araneid. We also propose additional candidate genes involved in synthesis of tubuliform or other silk types.

Aphyllin, the first isoferulic acid glycoside and other phenolics from Tamarix aphylla flowers.

The first glycosylated isoferulic acid, isoferulic acid 3-O-beta-glucopyranoside, together with the new phenolics, tamarixetin 3,3'-di-sodium sulphate and dehydrodigallic acid dimetyl ester have been characterized from a flower extract of Tamarix aphylla. The structures were established on the basis of spectral data. The extract exhibited a distinct radical scavenging effect and to improve the viability of human keratinocytes (HaCaT cells). Also, the known isoferulic acid and ferulic acid which have been determined to be the major components of the investigated extract by HPLC/ESI mass spectrometric screening have been separated, characterized and evaluated as active antioxidants and as cell activity stimulating agents as well.

Bone mineralization enhancing activity of a methoxyellagic acid glucoside from a Feijoa sellowiana leaf extract.

The capability of an aqueous methanol extract obtained from the leaves of Feijoa sellowiana Berg. on possible prevention and treatment of osteoporosis has been examined by evaluating its stimulating effect on the two human osteoblastic cell lines HOS58 and SaOS-2. The extract was found to increase significantly the mineralization of cultivated human bone cell, whereby a clear increment (15.3 +/- 2.7%) in von Kossa positive area was determined when administering 25 microg/ml leaf extract. A phytochemical investigation of the extract has demonstrated the high phenolic content and led to the isolation and identification of twenty three of them, among which the new 3-methoxyellagic acid 4-O-beta-glucopyranoside was fully identified. All structures were elucidated on the basis of conventional analytical methods and confirmed by FTMS, 1D- and 2D-NMR data. The new compound was found to cause a significant increase of mineralized area at 20 microg/mL, while at lower concentrations the effect was not significant. However, an increase of the number of mineralized spots (nodules) at all tested concentrations of the compound was observed.

An unique n-propyl sesquiterpene from Eryngium creticum L. (Apiaceae).

The unique 1-n-propyl-perhydronaphthaline 1,2,4a,5,6,7,8,8a-octahydro-4-methyl-1-propyl-naphthalene-7-carbaldehyde, a compound which possesses an unusual sesquiterpene carbon skeleton, was isolated and identified, together with the new natural methyl ketone eicos-8,11 -dien-18-ol-2-one, from the hexane: ether extract of the aerial parts of Eryngium creticum growing in Sinai, Egypt. The structures were established by conventional methods of analysis and confirmed by DEPT, COSY, HMQC and HMBC.