The solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) was used for the analysis of phenolic and other aromatic compounds in honey samples from different floral origin. Different parameters affecting the efficiency of the extraction, such as the type of the stationary phase of the fiber, NaCl and acetic acid addition, and extraction time, were optimized for the detection of the maximum number of compounds in the shortest analysis time. A total of 31 compounds were detected, with most of them identified and quantified by GC-MS. The principal component analysis (PCA) was applied to the data matrix; the results allowed for the differentiation between honeydew and nectar honeys on the basis of the salicylic acid concentration. It was found that this acid has a high contribution in the honeydew group (71.2-705.9 microg/100 g of honey) compared to the nectar honey group (0-47.6 microg/100 g of honey). The comparison of data in each honey group enabled us to characterize the floral source of some honeys using some aromatic compounds as markers.

Macrophage infectivity potentiator (MIP) was originally reported to be a chlamydial lipoprotein from experiments showing incorporation of radiolabeled palmitic acid into native and recombinant MIP; inhibition of posttranslational processing of recombinant MIP by globomycin, known to inhibit signal peptidase II; and solubility of native MIP in Triton X-114. However, the detailed structural characterization of the lipid moiety on MIP has never been fully elucidated. In this study, bioinformatics and mass spectrometry analysis, as well as radiolabeling and immunochemical experiments, were conducted to further characterize MIP structure and subcellular localization. In silico analysis showed that the amino acid sequence of MIP is conserved across chlamydial species. A potential signal sequence with a contained lipobox was identified, and a recombinant Chlamydiae are obligately intracellular gram negative bacteria that are major human pathogens capable of causing a wide range of diseases (11,12,24,34,43). All chlamydiae share a characteristic biphasic cycle of development with infectious, spore-like elementary bodies (EB) and intracellular dividing reticulate bodies (RB) that are metabolically active and inhabit a nonfusogenic inclusion (46). The mechanisms by which chlamydiae induce diseases are poorly understood but may include a proinflammatory immune response to chlamydial antigen (22), even if this antigen has yet to be unequivocally revealed (62). In many bacterial diseases, lipoproteins play a prominent role in pathogenesis, with a ubiquitous presence as major constituents of the bacterial cell wall. However, little is known about the actual existence and role of lipoproteins in chlamydiae. One of the few lipoproteins characterized so far, in Chlamydia trachomatis, is macrophage infectivity potentiator (MIP), which was identified as a lipoprotein by incorporation of radiolabeled palmitic acid into the native and recombinant proteins (41), inhibition of posttranslational processing of recombinant MIP (rMIP) by globomycin (a specific inhibitor of signal peptidase II [31]), and solubility of native MIP in Triton X-114 (42). Other studies have shown that C. trachomatis MIP is a 27-kDa membrane protein located in both EB and RB (38), with a COOH-terminal region showing high homology with eukaryotic and prokaryotic FK506 binding proteins (FKBP) (41) and exhibiting peptidyl-prolyl cis/trans isomerase (PPIase) activity (40). However, no evidence supporting the presence of a classical lipoprotein feature in MIP, similar to the murein lipoprotein from Escherichia coli (25), the best characterized bacterial lipoprotein, has been shown.Since chlamydiae are notably very atypical bacteria, phylogenetically separated from other eubacteria (48), we have conducted a detailed structural characterization of MIP. The probable signal sequence was determined by in silico analysis, and the cysteine in position 20 (cysteine 20 ) was predicted to be the lipobox cysteine (33,44). To assess the involvement of cysteine 20 in lipid modifi...

Analysis of aromatic compounds in the New Zealand manuka honey was carried out by solid phase microextraction followed by gas chromatography-mass spectrometry. A total of 38 compounds were detected. Seven of them such as; 1,4-bis(x-methoxyphenyl)-but-2-en-1-one, 1,5-bis(x-methoxyphenyl)-pent-3-en-1-one, 1,4-bis(x-methoxyphenyl)-1-pentanone, 1,6-bis(x-methoxyphenyl)-3-heptene, 1,6-bis(x-methoxyphenyl)-hex-2(3 or 4)-en-1-one and 2(3, 4 or 5)-hydroxy-1,6-bis(x-methoxyphenyl)-1-hexanone, had never before been identified as natural products. Their structures were deduced from the mass spectral data. Seven other compounds; 2,3-dimethoxynaphthalene, 4-(x-methoxyphenyl)-1-phenyl-1-butanone, desoxyanisoin, 2,6-dimethoxybenzoic acid benzyl ester, 4,4'-dimethoxystilbene, 3,3,4,5,5,8-hexamethyl-2,3,5,6-tetrahydro-s-indacene-1,7-dione and 1,5-bis(4-methoxyphenyl)-pentane-1,5-dione, were found in honey for the first time. Methyl syringate,ortho-methoxyacetophenone and 3-phenyllactic acid were the most abundant components.

The 13 2 ,17 3 -cyclopheophorbide a enol (CPP) is shown to convert mainly to a $1:1 mixture of (13 2 R=S) chlorophyllones a (Chlone), when chromatographed over silica gel or alumina supports. 15 1 -hydroxychlorophyllonelactone a and some other chlorophyll a related compounds are also tentatively identified as minor transformation products of CPP. This raises the possibility that the chlorophyllones reported in recent sediments may be analytical artifacts from CPP. However, data for the surface sediments from Lake Motte as well as literature data for other contemporary sediments show that, (i) they are not artifacts, (ii) considering that CPP is the intermediate compound in the formation of chlorophyllones from chlorophyll a, the hydroxylation of CPP in the sedimentary environment involves an enzymatic process leading preferentially to 13 2 S chlorophyllone a.