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Human cataractous lens nuclei extract inhibited, in a dose-dependent fashion, [3H]ouabain binding to rat brain synaptosomes and microsomal Na+-and K+-dependent adenosine triphosphate (Na+ , K+-ATPase) activity and interacted with anti-digoxin antibodies. The compounds responsible for these activities, termed digitalis-like compounds (DLC), were also detected in bovine, rat, cat and rabbit, normal, transparent lenses, but the levels were only 0.7-5.4% of the average levels in the cataractous human lenses. DLC from the human cataractous lenses were purified by a procedure consisting of organic extractions and batch chromatography followed by filtration through a 3000 Da cut-off filter and subsequent separations using reverse-phase high-performance liquid chromatography. The presence of DLC in the different fractions obtained in the chromatograms was monitored by their ability to inhibit [3H]ouabain binding and Na+, K+-ATPase activity. Based on chemical ionization mass spectrometry together with ultraviolet spectrometry and biological characterization, it is suggested that new bufodienolides, 19-norbufalin and 19-norbufalin peptide derivatives are responsible for the endogenous DLC activity. It is proposed that these compounds may regulate Na+, K+-ATPase activity in the lens under some physiological and pathological conditions.The Na+-and K+-dependent adenosine triphosphate (Na+, K'-ATPase) is an integral plasma membrane protein responsible for the maintenance of Na+ and K' concentration gradients in all eukaryotic cells. Since Na+, K'-ATPase has a high-affinity receptor for digitalis steroids, it has been postulated that there are endogenous ligands for these receptors which regulate the Na+, K' pump activity. Indeed, based on their ability to inhibit ['Hlouabain binding and Na+, K+-ATPase activity, digitalis-like compounds (DLC) have been shown to be present in the brain [l-31, heart [4] [24]. However, none of these compounds appears to be the natural ligand of the digitalis receptor of the Na+, K+-ATPase because of their limited specificity and affinity. Bufodienolides, which resemble the structure of the plant cardiac glycosides, have been identified in the plasma, brain and other tissues of toads [14, 15, 25, 261, however, their

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Phenserine, a phenylcarbamate of physostigmine, is a new potent and highly selective acetylcholinesterase (AChE) inhibitor, with a >50‐fold activity versus butyrylcholinesterase (BChE), in clinical trials for the treatment of Alzheimer's disease (AD). Compared to physostigmine and tacrine, it is less toxic and robustly enhances cognition in animal models. To determine the time‐dependent effects of phenserine on cholinergic function, AChE activity, brain and plasma drug levels and brain extracellular acetylcholine (ACh) concentrations were measured in rats before and after phenserine administration. Additionally, its maximum tolerated dose, compared to physostigmine and tacrine, was determined. Following i.v. dosing, brain drug levels were 10‐fold higher than those achieved in plasma, peaked within 5 min and rapidly declined with half‐lives of 8.5 and 12.6 min, respectively. In contrast, a high (>70%) and long‐lasting inhibition of AChE was achieved (half‐life >8.25 h). A comparison between the time‐dependent plasma AChE inhibition achieved after similar oral and i.v. doses provided an estimate of oral bioavailability of 100%. Striatal, in vivo microdialysis in conscious, freely‐moving phenserine‐treated rats demonstrated >3‐fold rise in brain ACh levels. Phenserine thus is rapidly absorbed and cleared from the body, but produces a long‐lasting stimulation of brain cholinergic function at well tolerated doses and hence has superior properties as a drug candidate for AD. It selectively inhibits AChE, minimizing potential BChE side effects. Its long duration of action, coupled with its short pharmacokinetic half‐life, reduces dosing frequency, decreases body drug exposure and minimizes the dependence of drug action on the individual variations of drug metabolism commonly found in the elderly.

The human pathogen Mycoplasma fermentans PG18 was isolated from the urogenital tract several decades ago (1). Because of reports indicating its possible role as a cofactor accelerating the progression of human immunodeficiency virus disease, its significance as a pathogen in other immunocompromised patients (2), and its role in the pathogenesis of rheumatoid arthritis, interest in M. fermentans has recently increased (3). Although little is known of the molecular mechanisms underlying M. fermentans pathogenicity (4), it has been shown that human immunodeficiency virus-associated cytopathic effects could be increased by the presence of M. fermentans (2) and that M. fermentans is capable of fusing with T-cells and peripheral lymphocytes (5).It is reasonable to assume that Mycoplasma membrane components are involved in the attachment and fusion of the microbe with eukaryotic host cells. Salman et al. (6) isolated an unusual phospholipid from the cell membranes of M. fermentans and showed that this material (compound X) was capable of enhancing the fusion of small, unilamellar vesicles with MOLT-3 lymphocytes in a dose-dependent manner.Matsuda et al. (4) isolated two glycoglycerolipids (GGPL-I 1 and GGPL-III) from M. fermentans. GGPL-I structure was shown to be 6Ј-O-phosphocholine-␣-D-glucopyranosyl-1,2-diacyl-sn-glycerol (7) as elucidated by mass and NMR spectroscopy. It was later shown (4) that the structure of a more polar glycolipid (GGPL-III) isolated from the same strain of M. fermentans was very similar to that of GGPL-I. The chemical structure of GGPL-III, however, has so far remained obscure. The only distinguishing structural feature known is that it differs from GGPL-I in having an additional amino residue (4). Both GGPLs were shown to be species-specific major lipid antigens of M. fermentans (4).Here we describe the structural analysis of a new type of polar lipid isolated from M. fermentans, and we present the complete structural analysis of MfGL-II. 2 Furthermore, we show that both glycolipids of M. fermentans, GGPL-I and GGPL-III, share the basic structure of 6Ј-O-phospho-␣-D-glucopyranosyl-(1Ј33)-1,2-diacyl-glycerol (7) but differ in their polar head groups. MATERIALS AND METHODS Growth of the Organism-Cultures of M. fermentans strain PG18and strain Incognitus (provided by S.-C. Lo, Armed Forces Institute of Pathology, Washington, D.C.) were grown in a modified Channock medium (8) inoculated with a 48-h culture at an inoculum level of 2% and incubated statically at 37°C. After 68 h the cells were harvested, washed twice, and freeze-dried as described previously (8) with yields ranging from 130 to 160 mg dry weight per liter of medium.Lipid Extraction and Purification-Freeze-dried cells were suspended in 25 mM Tris/HCl, pH 7.5, containing 0.25 M NaCl to a final concentration of 25 mg of cells per ml. Lipids were extracted from cell suspensions by the method of Bligh and Dyer (9) and concentrated to near dryness on a rotary evaporator. Quantitative separation of MfGL-II was achieved by silica gel colu...

BackgroundThe application of genotyping by sequencing (GBS) approaches, combined with data imputation methodologies, is narrowing the genetic knowledge gap between major and understudied, minor crops. GBS is an excellent tool to characterize the genomic structure of recently domesticated (~200 years) and understudied species, such as cranberry (Vaccinium macrocarpon Ait.), by generating large numbers of markers for genomic studies such as genetic mapping.ResultsWe identified 10842 potentially mappable single nucleotide polymorphisms (SNPs) in a cranberry pseudo-testcross population wherein 5477 SNPs and 211 short sequence repeats (SSRs) were used to construct a high density linkage map in cranberry of which a total of 4849 markers were mapped. Recombination frequency, linkage disequilibrium (LD), and segregation distortion at the genomic level in the parental and integrated linkage maps were characterized for first time in cranberry. SSR markers, used as the backbone in the map, revealed high collinearity with previously published linkage maps. The 4849 point map consisted of twelve linkage groups spanning 1112 cM, which anchored 2381 nuclear scaffolds accounting for ~13 Mb of the estimated 470 Mb cranberry genome. Bin mapping identified 592 and 672 unique bins in the parentals and a total of 1676 unique marker positions in the integrated map. Synteny analyses comparing the order of anchored cranberry scaffolds to their homologous positions in kiwifruit, grape, and coffee genomes provided initial evidence of homology between cranberry and closely related species.ConclusionsGBS data was used to rapidly saturate the cranberry genome with markers in a pseudo-testcross population. Collinearity between the present saturated genetic map and previous cranberry SSR maps suggests that the SNP locations represent accurate marker order and chromosome structure of the cranberry genome. SNPs greatly improved current marker genome coverage, which allowed for genome-wide structure investigations such as segregation distortion, recombination, linkage disequilibrium, and synteny analyses. In the future, GBS can be used to accelerate cranberry molecular breeding through QTL mapping and genome-wide association studies (GWAS).Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2802-3) contains supplementary material, which is available to authorized users.

The major unidentified polar lipid (compound X), recently demonstrated in the cell membrane of Mycoplasma fermentans, was purified by preparative silicic acid column chromatography. Chemical analyses of acid-hydrolyzed compound X revealed that, in addition to fatty acids, it contains glycerol, choline and phosphate in a molar ratio of approximately 1:1:2, and an amino acid that has a retention time similar to that of homoserine. The methylated fatty acid fraction of compound X was subjected to gas-liquid chromatography and revealed methyl palmitate and methyl stearate in a 4.6:1 molar ratio. The structure of compound X was further analyzed by combining mass spectrometry, 31P-NMR and 1H-NMR. The positive and negative fast atom bombardment spectra showed a major component of M(r) 1048 and a minor component of M(r) 1076. Two different phosphate groups were identified in each of the components by 31P-NMR. Fast atom bombardment, tandem mass spectrometry, negative and positive chemical ionization mass spectrometry together with mass spectra analyses of the water-soluble and ether-soluble products obtained by methanolysis has shown that, in addition to palmitic and stearic acid residues, the presence of glycerol, ribitol, cholinephosphate and homoserinephosphate residues. It is suggested that the apparent structure of compound X is either a phosphatidylcholine attached via a phosphotriester bond to a ribitolphosphohomoserine moiety or a phosphatidylhomoserine attached via a phosphotriester bond to a ribitolphosphocholine moiety. The major molecular species is the dipalmitoylderivative (M(r) 1048), whereas the minor molecular species is a stearoyl palmitoyl derivative (M(r) 1076).