Authenticity control of pine sylvestris essential oil by chiral gas chromatographic analysis of α-pinene.

Numerous terpenes present in essential oils (EOs) display one or more chiral centers. Within the same genus the enantiomeric ratio of these compounds can be different. Thus, the determination of enantiomers is a valuable tool to evaluate authenticity and quality of EOs. In here, the terpene profile of primary and commercial pine EOs was analyzed by conventional and chiral gas chromatography coupled to a flame ionization detector. The enantiomeric excess of ( ±)-α-pinene was determined and significant differences between primary and commercially available EOs were observed. Primary EOs of Pinus sylvestris L. showed a positive enantiomeric excess of (+)-α-pinene whereas commercial EOs labeled as P. sylvestris L. exhibited an enantiomeric excess of (-)-α-pinene. Thus, chiral analysis provides useful information on the authenticity of pine EOs and allows to uncover possible mislabeling, the use of the wrong herbal substance and sources of adulteration in pine oil.

Verification of Chromatographic Profile of Primary Essential Oil of Pinus sylvestris L. Combined with Chemometric Analysis.

Chromatographic profiles of primary essential oils (EO) deliver valuable authentic information about composition and compound pattern. Primary EOs obtained from Pinus sylvestris L. (PS) from different global origins were analyzed using gas chromatography coupled to a flame ionization detector (GC-FID) and identified by GC hyphenated to mass spectrometer (GC-MS). A primary EO of PS was characterized by a distinct sesquiterpene pattern followed by a diterpene profile containing diterpenoids of the labdane, pimarane or abietane type. Based on their sesquiterpene compound patterns, primary EOs of PS were separated into their geographical origin using component analysis. Furthermore, differentiation of closely related pine EOs by partial least square discriminant analysis proved the existence of a primary EO of PS. The developed and validated PLS-DA model is suitable as a screening tool to assess the correct chemotaxonomic identification of a primary pine EOs as it classified all pine EOs correctly.

A sulfated cyanobacterial polysaccharide proven as a strong inhibitor of human complement activity in an in vitro assay.

Cyanobacterial exopolysaccharides are a rich source of, so far, widely unexplored polysaccharides. One of these exopolysaccharides is a highly sulfated, linear polysaccharide from Synechocystis aquatilis containing the amino sugar N-acetyl-fucosamine. Some sulfated polysaccharides and glycosaminoglycans are known to be inhibitors of the human complement system, which is an important part of the innate immune system. Defects in this system or misregulation can cause serious diseases. Therefore, new compounds with complement inhibiting activity and simple test assays are of great interest. Exopolysaccharides from S. aquatilis (arabinofucans) were compared to those from Synechocystis pevalekii (complex heteropolysaccharides) and the well-known complement inhibitor heparin. Investigations were performed with a modified ELISA test system based on a commercially available test kit quantifying the membrane attack complex. Hereby the testing becomes more stable, robust, reproducible, easier to handle and, for the first time, the effect of exopolysaccharides and heparin on the lectin pathway could be tested. The exopolysaccharides from S. aquatilis could be shown to be a 30 times stronger inhibitor of the classical pathway of the complement system compared to heparin (IC50 = 0.3 µg/mL vs. 9.2 µg/mL). These exopolysaccharides are also inhibitors of the lectin pathway (IC50 = 10.8 µg/mL) in which, however, heparin is more potent (IC50 = 2.0 µg/mL). Interestingly, these exopolysaccharides do not inhibit the alternative pathway. The exopolysaccharides from S. pevalekii are inactive in all pathways. Furthermore, partially hydrolyzed and desulfated exopolysaccharides from S. aquatilis were tested showing that a minimum molecular size and degree of sulfation are important for the inhibitory effects, whereas unspecific influences by complex formation of exopolysaccharides with calcium could be excluded.

Exopolysaccharides of Synechocystis aquatilis are sulfated arabinofucans containing N-acetyl-fucosamine.

Cyanobacteria are known to be a rather diverse group of organisms regarding e.g. morphology, metabolism and composition of excreted exopolysaccharides (EPS). Considering the high number of known cyanobacterial species the EPS from only a small percentage are investigated in detail. This work examined EPS from the unicellular strains of Synechocystis aquatilis and S. pevalekii with various methods. The results emphasize the heterogeneity of cyanobacterial EPS. S. pevalekii secrets complex hetero-polysaccharides and acidic proteins as proteoglycan-complexes whereas the protein-free but highly sulfated EPS from S. aquatilis only consist of 4 dominant monosaccharides. Especially remarkable is the composition of these EPS: an arabinofucan with higher amounts of N-acetyl-fucosamine (FucNAc) and only minor quantities of glucose. Both EPS and the newly found component FucNAc in EPS from S. aquatilis extend the possible components of cyanobacterial EPS and the knowledge of heterogeneity of cyanobacterial metabolites.