Alcohol-based quorum sensing plays a role in adhesion and sliding motility of the yeast Debaryomyces hansenii.

The yeast Debaryomyces hansenii was investigated for its production of alcohol-based quorum sensing (QS) molecules including the aromatic alcohols phenylethanol, tyrosol, tryptophol and the aliphatic alcohol farnesol. Debaryomyces hansenii produced phenylethanol and tyrosol, which were primarily detected from the end of exponential phase indicating that they are potential QS molecules in D. hansenii as previously shown for other yeast species. Yields of phenylethanol and tyrosol produced by D. hansenii were, however, lower than those produced by Candida albicans and Saccharomyces cerevisiae and varied with growth conditions such as the availability of aromatic amino acids, ammonium sulphate, NaCl, pH and temperature. Tryptophol was only produced in the presence of tryptophane, whereas farnesol in general was not detectable. Especially, the type strain of D. hansenii (CBS767) had good adhesion and sliding motility abilities, which seemed to be related to a higher hydrophobicity of the cell surface of D. hansenii (CBS767) rather than the ability to form pseudomycelium. Addition of phenylethanol, tyrosol, tryptophol and farnesol was found to influence both adhesion and sliding motility of D. hansenii.

2,3-Dihydrohomofarnesal: female sex attractant pheromone component of Callosobruchus rhodesianus (Pic).

Callosobruchus rhodesianus (Pic) (Coleoptera: Chrysomelidae: Bruchinae) is a pest of stored legumes through the Afro-tropical region. In laboratory bioassays, males of C. rhodesianus were attracted to volatiles collected from virgin females. Collections were purified by various chromatographic techniques, and the biologically active component isolated using gas chromatographic-electroantennographic detection analysis. Gas chromatography-mass spectrometry and NMR analyses suggested that the active compound was 2,3-dihydrohomofarnesal, i.e., 7-ethyl-3,11-dimethyl-6,10-dodecadienal. The structure was confirmed by non-stereoselective and enantioselective total synthesis. Using chiral gas chromatography, the absolute configuration of the natural compound was confirmed as (3S,6E)-7-ethyl-3,11-dimethyl-6,10-dodecadienal. Y-tube olfactomter assays showed that only the (S)-enantiomer attracted males of C. rhodesianus. The (R)-enantiomer and racemate did not attract males, suggesting that the (R)-enantiomer inhibits the activity of the natural compound. In combination with previous reports about sex attractant pheromones of congeners, we suggest that a saltational shift of the pheromone structure arose within the genus Callosobruchus.

Farnesyl glycosides and one new triterpenoid saponin from the roots of Lecaniodiscus cupanioides Planch. ex Benth.

Chemical investigation of the methanol extract of the roots of Lecaniodiscus cupanioides led to the isolation and characterisation of three new sesquiterpene glycosides, named cupanioidesosides A (1), B (2) and C (3), together with one new triterpenoid saponin named lecanioside A (4), Their structures were established by extensive analysis of spectroscopic methods including 1D and 2D NMR techniques (COSY, NOESY, TOCSY, HSQC, and HMBC) and HRESIMS. The four new compounds were evaluated for their antiproliferative activity against the Caco-2 cell line (human epithelial cell line). None of the isolated compounds showed positive activity in our assay. Our findings represent a valuable contribution to the chemotaxonomy Lecaniodiscus genus of the subfamily of Sapindoideae of Sapindaceae family, known to be a rich source of farnesol glycosides.

Determination of salirasib (S-trans,trans-farnesylthiosalicylic acid) in human plasma using liquid chromatography-tandem mass spectrometry.

A liquid chromatography/tandem mass spectrometric (LC/MS/MS) assay was developed for the quantitative determination of salirasib (S-trans,trans-farnesylthiosalicylic acid, FTS) in human plasma. Sample pretreatment involved liquid-liquid extraction with methyl t-butyl ether of 0.5-mL aliquots of lithium heparin plasma spiked with the internal standard, S-trans,trans-5-fluoro-farnesylthiosalicylic acid (5-F-FTS). Separation was achieved on Waters X-Terra C(18) (50 mm x 2.1 mm i.d., 3.5 microm) at room temperature using isocratic elution with acetonitrile/10 mM ammonium acetate buffer mobile phase (80:20, v/v) containing 0.1% formic acid at a flow rate of 0.20 mL/min. Detection was performed using electrospray MS/MS by monitoring the ion transitions from m/z 357.2-->153.0 (salirasib) and m/z 375.1-->138.8 (5-F-FTS). Calibration curves were linear in the concentration range of 1-1000 ng/mL. A 5000 ng/mL sample that was diluted 1:10 (v/v) with plasma was accurately quantitated. The values for both within day and between day precision and accuracy were well within the generally accepted criteria for analytical method (<8.0%). This assay was subsequently used for the determination of salirasib concentrations in plasma of cancer patients after oral administration of salirasib at a dose of 400 mg.

A rapid quantitative assay for juvenile hormones and intermediates in the biosynthetic pathway using gas chromatography tandem mass spectrometry.

A method for rapid quantitation of insect juvenile hormones (JH) and intermediates in the biosynthetic pathway, both in vitro and in vivo (hemolymph and whole body), has been developed using GC-MS/MS. This method is as simple as the radiochemical assay (RCA), the most commonly used method for measurement of JH biosynthesis in vitro, without need for further purification and derivatization, or radioactive precursors or ligands. It shows high sensitivity, accuracy and reproducibility. Linear responses were obtained the range of 1-800 ng/mL (approximately 4-3000 nM). Recovery efficiencies for farnesol, farnesal, methyl farnesoate and JH III were approximately 100% in vitro and over 90% in vivo, with excellent reproducibility at three different spike levels. Titer of JH III in the hemolymph was relatively low at day 0 (adult female emergence) (79.68 ±â€¯5.03 ng/mL) but increased to a maximum of 1717 ng/mL five days later. In whole body, JH III quantity reached a maximum on day 4 (845.5 ±â€¯87.9 ng/g) and day 5 (679.7 ±â€¯164.6 ng/g) and declined rapidly thereafter. It is in agreement with the hemolymph titer changes and biosynthetic rate of JH in vitro. Comparison with the results of inhibition of JH biosynthesis by two known inhibitors (allatostatin (AST) mimic H17 and pitavastatin) using RCA and GC-MS/MS, showed that there was little difference between the two methods In contrast to other methods, the present method with GC-MS/MS can be used to elucidate the mechanism of inhibition by inhibitors of JH biosynthesis without any derivatization and purification. This method is applicable to screening of JH inhibitors and the study of inhibitory mechanisms with high sensitivity and accurate quantification. It may also be useful for the determination of JH titer in other Arthropods.

Characterization of (E,E)-farnesol and its fatty acid esters from anal scent glands of nutria (Myocastor coypus) by gas chromatography-mass spectrometry and gas chromatography-infrared spectrometry.

Several volatile compounds, including terpenoids, fatty alcohols, fatty acids and some of their esters, were identified from solvent extracts prepared from anal scent glands of nutria (a.k.a. coypu), a serious rodent pest ravaging wetlands in the USA. The major terpenoid constituents were identified as (E,E)-farnesol and its esters by a comparison of their gas chromatographic retention times, and electron-ionization (EI) and chemical-ionization (CI) mass spectra with those of authentic compounds. EI mass spectra of the four farnesol isomers are very similar, however, the ChemStation (Agilent) and GC-MS Solution (Shimadzu) software algorithms were able to identify the natural compound as the (E,E)-isomer, when a high-quality mass spectral library was compiled from reference samples and used for searching. Similarly, the esters were identified as those of (E,E)-farnesol. In contrast to EI spectra, the CI spectra of the (E,E)- and (E,Z)-isomers are distinctly different from those of the (Z,E)- and (Z,Z)-isomers. The intensities (I) of the peaks for the m/z 137 and 121 ions in the CI spectra offer a way of determining the configuration of the C-2 double bond of farnesols (for 2E isomers I(137)>I(121), whereas for 2Z isomers I(137)

The transcriptome of sesquiterpenoid biosynthesis in heartwood xylem of Western Australian sandalwood (Santalum spicatum).

The fragrant heartwood oil of West Australian sandalwood (Santalum spicatum) contains a mixture of sesquiterpene olefins and alcohols, including variable levels of the valuable sesquiterpene alcohols, α- and ß-santalol, and often high levels of E,E-farnesol. Transcriptome analysis revealed sequences for a nearly complete set of genes of the sesquiterpenoid biosynthetic pathway in this commercially valuable sandalwood species. Transcriptome sequences were produced from heartwood xylem tissue of a farnesol-rich individual tree. From the assembly of 12,537 contigs, seven different terpene synthases (TPSs), several cytochromes P450, and allylic phosphatases were identified, as well as transcripts of the mevalonic acid and methylerythritol phosphate pathways. Five of the S. spicatum TPS sequences were previously unknown. The full-length cDNA of SspiTPS4 was cloned and the enzyme functionally characterized as a multi-product sesquisabinene B synthase, which complements previous characterization of santalene and bisabolol synthases in S. spicatum. While SspiTPS4 and previously cloned sandalwood TPSs do not explain the prevalence of E,E-farnesol in S. spicatum, the genes identified in this and previous work can form a basis for future studies on natural variation of sandalwood terpenoid oil profiles.

Determination of E,E-farnesol in Makgeolli (rice wine) using dynamic headspace sampling and stir bar sorptive extraction coupled with gas chromatography-mass spectrometry.

In this paper, we analysed the volatile and semi-volatile compounds, including E,E-farnesol in Makgeolli which is a traditional type of Korean fermented rice wines. Forty-one compounds including alcohols, 1-butanol-3-methyl acetate, E,E-farnesol, stearol, and phytane, were separated and quantified by dynamic headspace sampling (DHS) and stir bar sorptive extraction (SBSE) coupled with gas chromatography-mass spectrometry. SBSE has been found to be an effective method for analysing E,E-farnesol levels in Makgeolli. The experimental parameters related to the extraction efficiency of the SBSE method, such as ethanol concentration and filtration, were studied and optimised. The linear dynamic range of the SBSE method for E,E-farnesol ranged from 0.02 to 200ngml(-1) with R(2)=0.9974. The limit of detection and limit of quantification of the SBSE method were 0.02 and 0.05ngml(-1), respectively. The relative standard deviation of intra- and inter-day reproducibility was less than 6.2% and 9.9%, respectively.

Candida albicans cell wall components and farnesol stimulate the expression of both inflammatory and regulatory cytokines in the murine RAW264.7 macrophage cell line.

Candida albicans causes candidiasis, secretes farnesol, and switches from yeast to hyphae to escape from macrophages after phagocytosis. However, before escape, macrophages may respond to C. albicans' pathogen-associated molecular patterns (PAMPs) through toll-like receptor 2 (TLR2) and dectin-1 receptors by expressing cytokines involved in adaptive immunity, inflammation, and immune regulation. Therefore, macrophages and the RAW264.7 macrophage line were challenged with C. albicans preparations of live wild-type cells, heat-killed cells, a live mutant defective in hyphae formation, a live mutant producing less farnesol, or an isolate producing farnesoic acid instead of farnesol. Interleukin-6 (IL-6), and IL-1ß, IL-10, and tumor necrosis factor-α (TNF-α) expression were evaluated by ELISA and/or qRT-PCR within 6 h after challenge. All viable strains producing farnesol, regardless of hyphae phenotype, induced IL-6, IL-1ß, IL-10, and TNF-α. To determine which components of C. albicans induced IL-6, RAW264.7 cells were incubated with farnesol, farnesoic acid, with or without zymosan, a yeast cell wall preparation that contains PAMPs recognized by TLR2 and dectin-1. The highest expression of IL-6, TLR2, and dectin-1 occurred when RAW264.7 cells were stimulated with zymosan and farnesol together. Our results suggest that the rapid expression of cytokines from macrophages challenged with C. albicans is due to cell-wall PAMPs combined with farnesol.

Separation of attogram terpenes by the capillary zone electrophoresis with fluorometric detection.

An original method based on capillary zone electrophoresis with fluorimetric detection has been developed for the determination of terpenic compounds. The method is based on the separation of a terpenes dynamically labeled by the non-ionogenic tenside poly(ethylene glycol) pyrenebutanoate, which was used previously for the labeling of biopolymers. The background electrolytes were composed of taurine-Tris buffer (pH 8.4). In addition to the non-ionogenic tenside aceton and poly(ethylene glycol) were used as the additives. The capillary zone electrophoresis with fluorometric detection at the excitation wavelength 335 nm and the emission wavelength 463 nm was successfully applied to the analysis of tonalid, cholesterol, vitamin A, ergosterol, estrone and farnesol at level of 10(-17) mol L(-1). Farnesol, is produced by Candida albicans as an extracellular quorum-sensing molecule that influences expression of a number of virulence factors, especially morphogenesis and biofilm formation. It enables this yeast to cause serious nosocomial infections. The sensitivity of this method was demonstrated on the separation of farnesol directly from the cultivation medium.

Recovery of E,E-farnesol from cultures of yeast erg9 mutants: extraction with polymeric beads and purification by normal-phase chromatography.

Saccharomyces cerevisiae erg9 mutants blocked at squalene synthase require ergosterol for growth and produce E,E-farnesol. Typically, at least half the amount of farnesol remains cell associated. Practically insoluble in water, farnesol can be extracted from production cultures of the erg9 mutants using either methanol/hexane or poly(styrene-co-divinylbenzene) beads. The first method consumes more solvents and requires centrifugation to clear an interface emulsion. The second method uses 50% less solvent and the beads can be used repeatedly for extraction. The solvent-free crude extract from the beads extraction contained higher concentration of farnesol (76-77%) than that from the solvent extraction (61-65%). Farnesol was obtained after normal-phase chromatography in high overall recovery (94%) and purity (99%).

Farnesylamine from the ant Monomorium fieldi Forel.

(2E)- and (2Z)-Farnesylamine were detected in the extracts of the myrmicine ant Monomorium fieldi Forel from Australia. Their structures were established by direct comparison with synthetic (2E)- and (2Z)-farnesylamine. This finding of a sesquiterpene is unique in a genus known to produce unbranched fatty acid derived alkaloids and amines. Additionally, while farnesylamine has not been reported from natural sources, the synthetic material has been shown to have a variety of biological activities.

The major carotenoid in all known species of heliobacteria is the C30 carotenoid 4,4'-diaponeurosporene, not neurosporene.

The carotenoids of five species of heliobacteria (Heliobacillus mobilis, Heliophilum fasciatum, Heliobacterium chlorum, Heliobacterium modesticaldum, and Heliobacterium gestii) were examined by spectroscopic methods, and the C30 carotene 4,4'-diaponeurosporene was found to be the dominant pigment; heliobacteria were previously thought to contain the C40 carotenoid neurosporene. In addition, trace amounts of the C30 diapocarotenes diapolycopene, diapo-zeta-carotene, diapophytofluene, and diapophytoene were also found. Up to now, diapocarotenes have been found in only three species of chemoorganotrophic bacteria, but not in phototropic organisms. Furthermore, the esterifying alcohol of bacteriochlorophyll g from all known species of heliobacteria was determined to be farnesol (C15) instead of the usual phytol (C20). Heliobacteria may be unable to produce geranylgeranyol (C20).

Quorum sensing in the dimorphic fungus Candida albicans is mediated by farnesol.

The inoculum size effect in the dimorphic fungus Candida albicans results from production of an extracellular quorum-sensing molecule (QSM). This molecule prevents mycelial development in both a growth morphology assay and a differentiation assay using three chemically distinct triggers for germ tube formation (GTF): L-proline, N-acetylglucosamine, and serum (either pig or fetal bovine). In all cases, the presence of QSM prevents the yeast-to-mycelium conversion, resulting in actively budding yeasts without influencing cellular growth rates. QSM exhibits general cross-reactivity within C. albicans in that supernatants from strain A72 are active on five other strains of C. albicans and vice versa. The QSM excreted by C. albicans is farnesol (C(15)H(26)O; molecular weight, 222.37). QSM is extracellular, and is produced continuously during growth and over a temperature range from 23 to 43 degrees C, in amounts roughly proportional to the CFU/milliliter. Production is not dependent on the type of carbon source nor nitrogen source or on the chemical nature of the growth medium. Both commercial mixed isomer and (E,E)-farnesol exhibited QSM activity (the ability to prevent GTF) at a level sufficient to account for all the QSM activity present in C. albicans supernatants, i.e., 50% GTF at ca. 30 to 35 microM. Nerolidol was ca. two times less active than farnesol. Neither geraniol (C(10)), geranylgeraniol (C(20)), nor farnesyl pyrophosphate had any QSM activity.

New polyoxygenated farnesylcyclohexenones, deacetoxyyanuthone A and its hydro derivative from the marine-derived fungus Penicillium sp.

New polyoxygenated farnesylcyclohexenones, 7-deacetoxyyanuthone A (1) and its 2,3-hydro derivative (2), were isolated together with the known farnesylquinones (3, 4) from a marine isolate of the genus Penicillium. The structures of the new deacetoxyyanuthone A (1) and its 2,3-hydro derivative (2) were assigned by spectroscopic methods, including 2D NMR and CD for the Cotton effect of alpha-epoxyketone experiments. Compounds 1 and 3 showed moderate in vitro cytotoxicity in a panel of five human tumor cell lines, and 1 also exhibited mild in vitro antibacterial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MIC, 50 microg/mL).