One-Step Preparative Separation of Phytosterols from Edible Brown Seaweed Sargassum horneri by High-Speed Countercurrent Chromatography

Sargassum horneri, a sargassaceae brown alga, is one of the main species in the subtidal seaweeds flora extensively distributed in the Yellow and East China Sea. It has been proven that the phytosterols are an important class of bioactive substances in S. horneri. In this work, a counter-current chromatography approach is proposed for preparative separation of phytol and two analogue sterols from a crude extract of S. horneri. A two-phase solvent system composed of n-hexane-acetonitrile-methanol (5:5:6, v/v) was selected and optimized. The effects of rotary speed and flow rate on the retention of the stationary phase were carefully studied. Under the optimum conditions, phytol and two analogue sterols, fucosterol and saringosterol, were baseline separated, producing 19.8 mg phytol, 23.7 mg fucosterol, and 3.1 mg saringosterol from 300 mg of crude S. horneri extract in one-step separation. The purities of three target compounds were all above 85%. The structures of phytol and two sterols were identified by nuclear magnetic resonance spectroscopy.

Neuroprotective effect of the marine macroalga Gelidiella acerosa: identification of active compounds through bioactivity-guided fractionation

Context Gelidiella acerosa (Forsskål) Feldmann & G. Hamel (Rhodophyta-Gelidiales) is a marine red macroalga. Our previous work found that a benzene extract of G. acerosa possesses noticeable neuroprotective activity, when evaluated through in vitro and in vivo systems. Objective Bioactive-guided fractionation and identification of active compounds by column chromatography using solvents of varying polarity. Materials and methods Fractionation was done by column chromatography, antioxidant and anticholinesterase activity was assessed by DPPH and cholinesterase inhibition assays (50-200 μg/ml), compound identification was done by LC-MS analysis, the mode of interaction of active compound was analyzed through docking studies and quantification was done by high-performance thin-layer chromatography (HPTLC) analysis. Results The results suggest that fractions F9-F13 exhibited significant (p < 0.05) antioxidant and anticholinesterase activities. Hence, these fractions were pooled together and verified for neuroprotective activity. The pooled fraction was subjected to LC-MS analysis and among all the compounds, phytol was previously reported to possess excellent neuroprotective potential. Hence, the neuroprotective potential of phytol was assessed. The results suggest that phytol showed significant (p < 0.05) antioxidant activities (25-125 μg/ml) with an IC50 value of 95.27 ± 1.65 μg/ml and cholinesterase inhibitory potential (5-25 μg/ml) with IC50 values of 2.704 ± 0.07 and 5.798 ± 0.72 μg/ml for AChE and BuChE, respectively. Molecular docking studies suggest that phytol interacts with cholinesterase through the arginine residue of the enzyme. HPTLC quantification showed that about 6.266 μg of phytol was present per mg of pooled fraction. Conclusion The study suggests that phytol might act as the key compound in contributing to the neuroprotective potential of G. acerosa.

Essential Oil Variation from Twenty Two Genotypes of Citrus in Brazil-Chemometric Approach and Repellency Against Diaphorina citri Kuwayama

The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-β-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.

Acute toxicity, antiedematogenic activity, and chemical constituents of Palicourea rigida Kunth

The phytochemical study of the leaves, roots, and flowers of Palicourea rigida led to the isolation of the triterpenes betulinic acid (1) and lupeol (2), the diterpene phytol (3), and the iridoid glycosides sweroside (4) and secoxyloganin (5). These compounds were identified using NMR 1H and 13C and comparing the spectra with published data. We studied the antiedematogenic activity of crude extracts from the organs, and of different fractions, in mice and found that the n-hexane fraction of the leaf extract significantly inhibited the ear edema resulting from croton oil administration. The crude extract from leaves was not acutely toxic to the mice.

Remobilization of Phytol from Chlorophyll Degradation Is Essential for Tocopherol Synthesis and Growth of Arabidopsis

Phytol from chlorophyll degradation can be phosphorylated to phytyl-phosphate and phytyl-diphosphate, the substrate for tocopherol (vitamin E) synthesis. A candidate for the phytyl-phosphate kinase from Arabidopsis thaliana (At1g78620) was identified via a phylogeny-based approach. This gene was designated VITAMIN E DEFICIENT6 (VTE6) because the leaves of the Arabidopsis vte6 mutants are tocopherol deficient. The vte6 mutant plants are incapable of photoautotrophic growth. Phytol and phytyl-phosphate accumulate, and the phytyl-diphosphate content is strongly decreased in vte6 leaves. Phytol feeding and enzyme assays with Arabidopsis and recombinant Escherichia coli cells demonstrated that VTE6 has phytyl-P kinase activity. Overexpression of VTE6 resulted in increased phytyl-diphosphate and tocopherol contents in seeds, indicating that VTE6 encodes phytyl-phosphate kinase. The severe growth retardation of vte6 mutants was partially rescued by introducing the phytol kinase mutation vte5. Double mutant plants (vte5 vte6) are tocopherol deficient and contain more chlorophyll, but reduced amounts of phytol and phytyl-phosphate compared with vte6 mutants, suggesting that phytol or phytyl-phosphate are detrimental to plant growth. Therefore, VTE6 represents the missing phytyl-phosphate kinase, linking phytol release from chlorophyll with tocopherol synthesis. Moreover, tocopherol synthesis in leaves depends on phytol derived from chlorophyll, not on de novo synthesis of phytyl-diphosphate from geranylgeranyl-diphosphate.

Insecticidal activity of Jatropha curcas extracts against housefly, Musca domestica

The hexane and ether extracts of leaves, bark and roots of Jatropha curcas were screened for their toxicity against different developmental stages of housefly. The larvicidal, pupicidal and adulticidal activities were analysed at various concentrations (0.78-7.86 mg/cm(2)) of hexane and ether extracts. The lethal concentration values (LC50) of hexane extract of J. curcas leaves were 3.0 and 0.27 mg/cm(2) for adult and larval stages of housefly, respectively, after 48 h. Similarly, the ether extract of leaf showed the LC50 of 2.20 and 4.53 mg/cm(2) for adult and larval stages of housefly. Least toxicity was observed with hexane root extract of J. curcas with LC50 values of 14.18 and 14.26 mg/cm(2) for adult and larvae of housefly, respectively, after 48 h. The variation in LC50 against housefly pupae was found to be 8.88-13.10 mg/cm(2) at various J. curcas extract concentrations. The GC-MS analysis of J. curcas leaf extract revealed the presence of trans-phytol (60.81 %), squalene (28.58 %), phytol (2.52 %) and nonadecanone (1.06 %) as major components that could be attributed for insecticidal activity of J. curcas extracts.

Acclimation mechanisms elicited by sprayed abscisic acid, solar UV-B and water deficit in leaf tissues of field-grown grapevines

The independent and interactive effects of solar ultraviolet-B radiation (UV-B), moderate water deficit and sprayed abscisic acid (ABA) on leaves gas exchange and biochemical aspects of field-grown grapevines of the cv. Malbec were investigated in a high altitude vineyard (1450 m a.s.l.). Two UV-B treatments (ambient solar UV-B or reduced UV-B), two watering treatments (well watered or moderate water deficit) and two ABA treatments (no ABA and sprayed ABA) were given alone and combined in a factorial design. Gas exchange and photosynthesis were reduced by water deficit and highly impaired in the UV-B and water deficit combined treatment. UV-absorbing compounds were stimulated independently by UV-B. The monoterpenes α-pinene, 3-carene and terpinolene, and the sesquiterpene nerolidol were augmented by UV-B, water deficit or sprayed ABA. Levels of the triterpene squalene and the diterpene phytol were significantly higher in the treatment that combined UV-B, water deficit and ABA applications. Environment signals (solar UV-B and moderate water deficit) and sprayed ABA elicited mechanisms of acclimation by augmenting the content of terpenes with antioxidant and antifungal properties, thus enhancing the plant defensive mechanisms towards signals both biotic and abiotic.

Activity against microorganisms affecting cellulosic objects of the volatile constituents of Leonotis nepetaefolia from Nicaragua

The chemical composition of the essential oil from aerial parts of L. nepetaefolia (L.) R. Br. collected in Nicaragua was evaluated by GC and GC-MS. The main components were (Z)-phytol (22.8%), caryophyllene oxide (18.9%) and hexahydrofarnesylacetone (9.0%). The antibacterial activity against several Gram + and Gram - bacteria, including Bacillus cereus and B. subtilis, both infesting historical cellulosic material, was also determined. B. cereus, B. subtilis and Staphylococcus epidermis were the most affected by the action of the oil.

[Chemical components from essential oil of Pandanus amaryllifolius leaves]

OBJECTIVE

To analyze the chemical compositions of Pandanus amaryllifolius leaves essential oil extracted by steam distillation.

METHODS

The essential oil of Pandanus amaryllifolius leaves was analyzed by gas chromatography-mass spectrum, and the relative content of each component was determined by area normalization method.

RESULTS

128 peaks were separated and 95 compounds were identified, which weighed 97.75%. The main chemical components of the essential oil were phytol (42.15%), squalene (16.81%), what's more pentadecanal (6.17%), pentadecanoic acid (4.49%), 3, 7, 11, 15-tetramethyl-2-hexadecen-1-ol (3.83%), phytone (2.05%) and the other 74 chemical compositions were firstly identified from the essential oil of Pandanus amaryllifolius leaves.

CONCLUSION

The chemical compositions of Pandanu samaryllifolius leaves essential oil was systematically, deeply isolated and identified for the first time. This experiment has provided scientific foundation for further utilization of Pandanus amaryllifolius leaves.

[Study on volatile components from flowers of Gymnema sylvestre]

OBJECTIVE

To analyze the volatile components from flowers of Gymnema sylvestre.

METHODS

Volatile components of flowers of Gymnema sylvestre were extracted by water vapor distilling, and the components were separated and identified by GC-MS.

RESULTS

55 components were separated and 33 components were identified, accounting for 88.73% of all quantity. The principal volatile components are Phytol, Pentacosane, 10-Heneicosene (c, t), 3-Eicosene, (E) -and 2-Methyl-Z-2-docosane.

CONCLUSION

The research can pro-vide scientific basis for chemical component research of flowers of Gymnema sylvestre.

Phytol/Phytanic acid and insulin resistance: potential role of phytanic acid proven by docking simulation and modulation of biochemical alterations

Since activation of PPARγ is the main target for the antidiabetic effect of TZDs, especially when it heterodimerizes with RXR, we aimed to test the potential antidiabetic effect of phytol (250 mg/kg), the natural precursor of phytanic acid, a RXR ligand and/or pioglitazone (5 mg/kg) to diabetic insulin-resistant rats. Regarding the molecular docking simulation on PPARγ, phytanic acid, rather than phytol, showed a binding mode that mimics the crystal orientation of rosiglitazone and pioglitazone, forming H bonds with the same amino acids (S289, H 323, H 449 and Y 473), and the least energy level, which emphasizes their importance for PPARγ molecular recognition, activation, hence antidiabetic activity. In addition, docking on the RXRα/PPARγ heterodimer, revealed that phytanic acid has higher binding affinity and lesser energy score on RXRα, compared to the original ligand, retinoic acid. Phytanic acid binds by 3H bonds and shares retinoic acid in arginine (R 316). These results were further supported biochemically, where oral phytol and/or pioglitazone (5 mg/kg) improved significantly glucose homeostasis, lipid panel, raised serum adiponectin level and lowered TNF-α, reaching in most cases the effect of the 10 mg/kg pioglitazone. The study concluded that the insulin sensitizing/anti-diabetic effect of phytol is mediated by partly from activation of nuclear receptors and heterodimerization of RXR with PPARγ by phytanic acid.

Antiplasmodial activity of the ethnobotanical plant Cassia fistula

In our ongoing investigation of new compounds with activity against malaria parasites, we tested the in vitro antiplasmodial activity of fractions and purified compounds from Cassia fistula L., a plant traditionally used by native populations of Tanzania, Zimbabwe, Mozambique and Brazil to treat malaria or symptoms associated with this disease. Crude extracts from leaves, bark and fruits were tested for their antiplasmodial activity against the chloroquine-sensitive strain of Plasmodium falciparum (D10), where leaf extracts showed the highest activity. The chloroform extract of the leaves was further bioassay-guided fractionated using a combination of centrifugal partition chromatography and flash column chromatography. Three main antiplasmodial principles, phytol (1) (IC50 18.9 +/- 0.60 microM), lutein (2) (IC50 12.5 +/- 0.35 microM), and di-lineolylgalactopyranosyl-glycerol (DLGG) (IC50 5.8 +/- 0.27 microM) (3), were isolated and identified using spectroscopic methods. When the three active principles were tested for their cytotoxicity using a Chinese Hamster Ovarian (CHO) cell line, compound 3 showed very weak toxicity (IC50 75.9 +/- 0.28 microM), while the other two compounds were nontoxic, even at the highest concentration tested. The study provides evidence to support the use of Cassia fistula as an antimalarial remedy and describes the antiplasmodial constituents from the leaves.

Differentiation of refined and virgin edible oils by means of the trans- and cis-phytol isomer distribution

The differentiation of nonrefined (e.g., cold-pressed) and refined edible oils is an important task in food control because of the higher commercial value of the former. Here, we explored the suitability of the relative abundance of cis-phytol as a marker for authentication of nonrefined edible oils. Phytol, the tetramethyl-branched, monoenoic alcohol, is found widespread in nature as a part of chlorophyll. In chlorophyll, only trans-phytol is found. In this study, we present a method for the analysis of the phytol isomers, considering that traces of cis-phytol (contributing 0.1% to the phytol content) can be determined next to trans-phytol. For this purpose, phytol was gathered with the unsaponifiable matter from the oil, trimethylsilylated, and analyzed by gas chromatography coupled to mass spectrometry. With this method, 27 samples of edible oils (16 refined and 11 nonrefined edible oils) were analyzed for the abundance of cis-phytol relative to trans-phytol. In the nonrefined oils (e.g., olive oil, rapeseed oil, maize oil, and sunflower oil), cis-phytol contributed 0.1% (n = 3) or less (n = 8) to the phytol content. In contrast, the refined olive oils (n = 4) contained a share of 1.3-3% cis-phytol; the refined rapeseed oil (n = 3) contained a share of 0.7-1.0% cis-phytol; and the refined sunflower oil (n = 4) contained a share of 0.3-0.9% cis-phytol. Only one refined pomegranate kernel did not contain cis-phytol. The phytol concentration was not suited to distinguish nonrefined from refined oils. In contrast, our data suggest that the virtual absence of cis-phytol can be used as a marker for nonrefined (e.g., cold-pressed) edible oils.

[Study on the volatile oil of leaf of red gland Lonicera in guangxi]

OBJECTIVE

To compare volatile oil of Lonicera confusa (red gland Lonicera) fresh leaves with dry leaves and provide evidence for further study of Lonicera confusa leaves.

METHODS

GC-MS was used to identify chemical composition in volatile oil in red gland Lonicera leaves.

RESULTS

93 chemical components were separated in fresh leaves in which 39 chemical components were identified; 88 chemical components were separated in dry leaves in which 51 chemical components were identified. The main components of fresh leaves of red gland Lonicera were n-Hexadecanoic acid (11.90%), Phytol (11.79) and 9,12,15-Octadecatrienoic acid, methyl ester, (Z, Z, Z)(7.08); The main components of dry leaves of red gland Lonicera were 1,6-Octadien-3-ol, 3,7-dimethyl-(27.62%), Phytol (7.57%) and 2, 6, 10, 14, 18, 22-Tetracosahexaene, 2, 6, 10, 15, 19, 23-hexamethyl-, (all-E) (4.70%).

CONCLUSION

There are significant differences between volatile oil between fresh and dry leaves.

Anti-scratching behavioral effect of the essential oil and phytol isolated from Artemisia princeps Pamp. in mice

The anti-scratching behavioral effect of the essential oil and phytol isolated from Artemisia princeps Pamp. (AP, family Asteraceae), which is widely used in traditional medicine for inflammatory diseases, was investigated IN VIVO. Treatment of mice with AP essential oil (APEO) and phytol inhibited histamine- and compound 48/80-induced scratching behaviors. The anti-scratching behavioral effects of APEO and phytol are in proportion to their vascular permeability-inhibitory effects. These agents also inhibited the level of allergic cytokines, IL-4, and TNF- α, and the activation of transcription factors, NF- κB and c-jun (AP-1), in histamine-treated skin tissues. Based on these results, APEO and phytol may improve scratching behavior in skin by inhibiting the expression of allergic cytokines via the regulation of NF- κB and AP-1 activation.

[Analysis of volatile oil from Ardisia brevicaulis]

OBJECTIVE

To analyze and compare the compounds in the essential oil from the leaves and roots of Ardisia brevicaulis.

METHODS

The essential oil were obtained by steam distillation. The chemical components were separated and identified by gas chromatography-mass spectrometry (GC-MS).

RESULTS

38 compounds were identified from the leaves (65.952% of the total essential oil) and 46 compounds were identified from the roots (54.890% of the total essential oil). The main constituents of the leaves essential oil were Palmitic acid (43.329%), Fitone (2.430%), Phytol (3.142%), and so on. The main constituents of the roots essential oil were Calamenene (2.913%), cis-alpha-Bisabolene (5.222%), gamma-Muurolene (14.227%), Caryophyllene (11.592%), and so on.

CONCLUSION

The constituents of volatile oil extracted from the leaves and roots of Ardisia brevicaulis were different, so the leaves and roots of Ardisia brevicaulis should be utilized differently in clinical application.

Aphrodisiac pheromones from the wings of the small cabbage white and large cabbage white butterflies, Pieris rapae and Pieris brassicae

The small and large cabbage butterflies, Pieris rapae and P. brassicae, are found worldwide and are of considerable economic importance. The composition of the male scent-producing organs present on the wings was investigated. More than 120 components were identified, but only a small portion proved to be male specific. Major components were the known beetle pheromone ferrulactone (1) in P. rapae and its previously unknown larger analogue, brassicalactone (2), in P. brassicae. The latter carries an additional isoprene unit and is closely related to 1. Other components present in larger amounts on male relative to female wings were hexahydrofarnesylacetone (18) and phytol (23). Brassicalactone (2) was fully characterized by synthesis of its various diastereomers by using ring-closing metathesis. A similar approach to ferrulactone (1) failed, presumably because of its smaller ring size. Instead, this compound was synthesized by using a modified literature procedure. The biological activity of the compounds in the extract was tested by coupled gas chromatographic-electroantennographic (GC-EAD) analysis, which showed that both macrolides and the other major components of the wings can be detected by the antennae of the conspecific female butterflies. Other detectable compounds included several alkanes, which are typical constituents of the butterfly cuticula, derivatives of phytol (23) and long-chain secondary alcohols. Finally, bioassays with males showed that the mixture of 1 (P. rapae) or 2 (P. brassicae) together with 18 and 23 applied to freshly eclosed males increased mating success compared to untreated males. Therefore, the two macrolides 1 and 2 are aphrodisiac pheromone components of male small and large cabbage white butterflies, respectively.

[Extraction and GC-MS analysis of essential oil from leaves of Discocleidion rufescens]

OBJECTIVE

To analyse the compositions of essential oil from leaves of Discocleidion rufescens.

METHODS

To isolate by steam distillation and analyze by GC-MS.

RESULTS

37 compounds, representing 92.25% of total oil were indentified and their relative amount was determined.

CONCLUSION

The oil is rich in Phytol (39.30%, n-Hexadecanoic acid (11.72%), (Z) -3-Teoadecen-5-yne (5.78%) and beta-Pinene (3.63%).

[Studies on chemical constituents of Laurencia tristicha ( II )]

OBJECTIVE

To search for chemical constituents with structural diversity from Laurencia tristicha to supply for biological assay.

METHOD

Compounds were isolated by means of column chromatography over normal phase silica gel and Sephadex LH-20, recrystallization and HPLC. Structures were identified by spectroscopic methods including 1D NMR, IR and MS. Cytotoxicities of the purified compounds were evaluated by MTT method.

RESULT

Seven compounds were isolated from L. tristicha. Their structures were elucidated as cholesterol (1), cholesta- 5-en-3beta, 7alpha-diol (2), beta-stigmasterol (3), phytol (4), zeaxanthin (5), 4 -hydroxybenzaldehyde (6), indolyl-3-carbaldehyde (7). In the cytotoxic assay compound 2 was active against human cancer cell lines HCT-8, Bel-7402, BGc-823, A549 and HELA with IC50 values of 1.90, 2.02, 1.99, 6.52 and 1.20 microg x mL(-1), respectively. Compound 4 showed cytotoxicity against HCT-8 and HELA with IC50 value of 3.51 and 2.04 microg x mL(-1), and other compounds were inactive ( IC50 > 10 microg x mL(-1)).

CONCLUSION

Compounds 1-7 were isolated from L. tristicha for the first time. In additon, compounds 2 and 4 were cytotoxic against several human cancer cell lines.

[Chemical constituents from red alga Corallina pilulifera]

OBJECTIVE

To investigate the chemical constituents of red alga Corallina pilulifera.

METHOD

Compounds were isolated by normal phase silica gel and Sephadex LH - 20 gel column chromatography, reverse phase HPLC and recrystallization. Their structures were elucidated by spectroscopic methods including MS, 1H-NMR, 13C-NMR, HSQC, HMBC. Cytotoxicity of the compounds was screened by using standard MTT method.

RESULT

Seven compounds were isolated from red alga C. pilulifera, their structures were identified as (E) -phytol epoxide (1), phytenal (2), phytol (3), dehydrovomifoliol (4), loliolide (5), 3beta-hydroxy-5alpha, 6alpha-epoxy-7-megastigmene-9-one (6), 4-hydroxybenzaldehyde (7).

CONCLUSION

All of the compounds were obtained from this species for the first time. These compounds were inactive (IC50 > 10 microg x mL(-1)) in the MTT assay.

[Chemical constituents from herb of Alternanthera philoxeroides]

OBJECTIVE

To study the active constituents from Alternanthera philoxeroides.

METHOD

The constituents were isolated with silica gel and Toyopearl HW-40C gel column chromatography and purified by HPLC. Their structures were elucidated by spectroscopy.

RESULT

Nine compounds were isolated and identified as phaeophytin a (1), pheophytin a' (2), oleanoic acid (3), beta-sitosterol (4), 3beta-hydroxystigmast-5-en-7-one (5), alpha-spinasterol (6), 24-methylenecycloartanol (7), cycloeucalenol (8), phytol (9).

CONCLUSION

Compounds 1,2,5,7-9 were isolated from this plant for the first time.

Langmuir−Blodgett Films of a Novel Cellulose Derivative with Dihydrophytyl Group: The Ability to Anchor β-Carotene Molecules

A novel cellulose derivative, 6-O-dihydrophytylcellulose (DHPC), was first synthesized via a ring-opening polymerization and allowed to self-assemble onto an air-water interface. Langmuir-Blodgett (LB) films were characterized with atomic force microscope (AFM), UV-vis spectroscopy, and Fourier transform infrared spectroscopy. The surface pressure-area (pi-A) isotherms for DHPC and beta-carotene (betaC) mixture indicated strong interaction between these compounds to pack well. Thus, DHPC has the ability to anchor betaC in the monolayer. It was proved that a betaC-DHPC monolayer was transferred successfully onto a substrate, yielding Y-type LB films by UV spectroscopic analysis. The transmission and reflection-absorption IR spectra (RAS) indicated that the dihydrophytyl chains had almost trans-zigzag conformation and were oriented nearly perpendicular to the substrate. AFM section analysis revealed the thickness per layer to be 2.32 nm. Consequently, DHPC was found to be an appropriate matrix to fabricate the mixed LB films containing betaC.

Membrane on a chip: a functional tethered lipid bilayer membrane on silicon oxide surfaces

Tethered membranes have been proven during recent years to be a powerful and flexible biomimetic platform. We reported in a previous article on the design of a new architecture based on the self-assembly of a thiolipid on ultrasmooth gold substrates, which shows extremely good electrical sealing properties as well as functionality of a bilayer membrane. Here, we describe the synthesis of lipids for a more modular design and the adaptation of the linker part to silane chemistry. We were able to form a functional tethered bilayer lipid membrane with good electrical sealing properties covering a silicon oxide surface. We demonstrate the functional incorporation of the ion carrier valinomycin and of the ion channel gramicidin.

The Arabidopsis vitamin E pathway gene5-1 mutant reveals a critical role for phytol kinase in seed tocopherol biosynthesis

We report the identification and characterization of a low tocopherol Arabidopsis thaliana mutant, vitamin E pathway gene5-1 (vte5-1), with seed tocopherol levels reduced to 20% of the wild type. Map-based identification of the responsible mutation identified a G-->A transition, resulting in the introduction of a stop codon in At5g04490, a previously unannotated gene, which we named VTE5. Complementation of the mutation with the wild-type transgene largely restored the wild-type tocopherol phenotype. A knockout mutation of the Synechocystis sp PCC 6803 VTE5 homolog slr1652 reduced Synechocystis tocopherol levels by 50% or more. Bioinformatic analysis of VTE5 and slr1652 indicated modest similarity to dolichol kinase. Analysis of extracts from Arabidopsis and Synechocystis mutants revealed increased accumulation of free phytol. Heterologous expression of these genes in Escherichia coli supplemented with free phytol and in vitro assays of recombinant protein produced phytylmonophosphate, suggesting that VTE5 and slr1652 encode phytol kinases. The phenotype of the vte5-1 mutant is consistent with the hypothesis that chlorophyll degradation-derived phytol serves as an important intermediate in seed tocopherol synthesis and forces reevaluation of the role of geranylgeranyl diphosphate reductase in tocopherol biosynthesis.

Phytol-modified heme in mesoporous silica: Conjugates as models of hemoproteins

A ferriprotoporphyrin, hemin (Fe(3+)), modified with 3,7,11,15-tetramethyl-2-hexadecen-1-ol, phytol, was adsorbed in nano-spaces of about 4 nm in diameter in mesoporous silica (FSM; folded-sheet mesoporous material) forming a phytol-modified hemin (Fe(3+))-FSM nano-conjugate. The properties and the structure of the conjugate were studied by UV-visible light absorption, IR absorption spectroscopy, and a nitrogen adsorption isotherm. Although the hemin without phytol could not be adsorbed to the mesoporous silica, modification with phytol imparted preferential adsorption properties. The conjugate was not only stable but also had a peroxidase-like activity in a 0.1% hydrogen peroxide solution, while free hemin in the solution was easily destroyed. The hemin (Fe(3+)) in the FSM was reduced to heme (Fe(2+)) by hydrazine. The phytol-modified heme (Fe(2+))-FSM conjugate formed an O(2)-heme complex with a superoxide type structure, resembling oxyhemoglobin or oxymyoglobin, which has not been previously observed for free heme in solution. The addition of carbon monoxide or nitrogen monoxide to the phytol-modified heme (Fe(2+))-FSM conjugate caused the formation of CO- or NO-heme complex in the nano-spaces of the FSM. These properties are attributed not only to the Fe-complex but also to the cooperative functions of the heme with mesoporous silica, resembling properties of a natural heme-protein conjugate; hemoglobin or peroxidase. These results are an elegant example of biomimetic nano-technology.

Ovipositional deterrent on mature stage of sweet pepper, Capsicum annuum, against Liriomyza trifolii (Burgess)

Liriomyza trifolii (Burgess), the American serpentine leafminer fly, is a well-known serious pest in the world. This insect species attacks plants of more than 21 families including Solanaceae plants. A sweet pepper, Capsicum annuum (Solanaceae), on mature stage, however, shows resistance to this leafminer fly. This resistance is based on the ovipositional deterrent in the sweet pepper leaf against the fly species. Based on the bioassay guided fractionation, phytol [(2E)-3,7,11,15-tetramethyl-2-hexadecen-1-ol] was isolated and identified as an ovipositional deterrent against this insect species. The yield of this compound was 815 microg/g fresh leaf of C. annuum. This compound completely deterred the females from laying their eggs on host plant leaves treated at 35.2 microg/cm2.

A novel assay for the prenatal diagnosis of Sjögren-Larsson syndrome

Sjögren-Larsson syndrome (SLS) is a metabolic disorder characterized by ichthyosis, mental retardation and spastic diplegia or tetraplegia. The biochemical defect has been identified as a deficiency of fatty aldehyde dehydrogenase (FALDH), which is part of an enzyme complex that converts fatty alcohols into fatty acids. Making use of the finding that FALDH is also involved in the degradation of phytol, we set up an enzymatic assay for the prenatal diagnosis of SLS in cultured chorionic villus fibroblasts (CVF) based on a deficiency in the conversion of phytol to phytenic acid. FALDH activity was assessed by incubating fibroblast homogenates with phytol in the presence of NAD+, followed by hexane extraction of the samples and quantification of phytenic acid production by gas chromatography-mass spectrometry (GC-MS). FALDH activity could be detected in cultured CVF cells derived from control fetuses and the activity was found to be markedly deficient in cultured CVF cells derived from an affected SLS fetus. The new assay described in this paper has advantages over previous assays and we conclude that it may well contribute to the prenatal detection of SLS.

Diterpene derivative and chromone fromHypericum Perforatum

A novel diterpene derivative, 5-methyl-5-(4,8,12-trimethyl-tridecyl)-dihydro-furan-2-one (1) and a new chromone, 5-hydroxy-7-methoxy-3-methyl-chromen-4-one (2), along with a known compound, phytol (3) have been isolated from the aerial parts of Hypericum perforatum. Their structures were established on the basis of spectroscopic analysis and by comparison with published values.

Fern Constituents: Dryocrassy Formate, Sitostanyl Formate and 12.ALPHA.-Hydroxyfern-9(11)-ene from Cyathea podophylla

Dryocrassyl formate, sitostanyl formate, and 12alpha-hydroxyfern-9(11)-ene were isolated from the fresh fronds of Cyathea podophylla. Their structures were elucidated by spectroscopic techniques and synthesis. Ten known triterpenoids, three derivatives of phytol, a stanol, and beta-tocopherol were also identified from this fern.

Simulated moving bed chromatography with supercritical fluids for the resolution of bi-naphthol enantiomers and phytol isomers

The combination of the simulated moving bed (SMB) technique with supercritical fluid chromatography (SFC) leads to a process with unique features. Besides the known advantages of the SMB process, the use of supercritical carbon dioxide as the mobile phase offers the advantages of reduction in organic solvents and an easy eluent/solute separation. Because of the low viscosity and high diffusion coefficients of supercritical fluids, a high efficiency is possible. The steps of process development for SMB SFC are presented using the separations of the bi-naphthol enantiomers and phytol isomers as examples. The development of a packed column SFC method at an analytical scale is shown for the separation of the bi-naphthol enantiomers on a chiral stationary phase and CO(2) with a modifier as the mobile phase. The influence of the modifier, modifier content, and column configuration on productivity of the SMB SFC process was investigated by simulation. The first set of experiments was performed in the SMB separation of phytol isomers at low concentration to test the feasibility of the SMB SFC high purity separation of the binary mixtures. In the second set of experiments, the productivity of the process was increased by increasing the feed concentration up to 54 grams feed per liter stationary phase (SP) and hour (g(feed)/l(SP) h).

Composition and antimicrobial activity of the essential oil of Ballota pseudodictamnus L. Bentham

The chemical composition of the essential oil of Ballota pseudodictamnus obtained from the aerial parts was analysed by GC/MS. From the 52 identified constituents of the oil, caryophyllene oxide, phytol and gamma-muurolene were the major components. Furthermore, the essential oil was investigated for its antimicrobial activity.

Diol- and triol-types of phytol induce apoptosis in lymphoid leukemia Molt 4B cells

The exposure of human lymphoid leukemia Molt 4B cells to diol- and triol-types of phytol which were synthesized and identified by Mass, and 1H- and 13C-NMR, led to both growth inhibition and induction of programmed cell death (apoptosis). Morphological changes showing apoptotic bodies were observed in the Molt 4B cells treated with diol- and triol-types of phytol. The fragmentations of DNA by the diol- and triol-types of phytol to oligonucleosomal-sized fragments, that is a characteristic of apoptosis, were observed to be both concentration- and time-dependent. These findings suggest that growth inhibition of Molt 4B cells by the diol- and triol-types of phytol results from the induction of apoptosis in the leukemic cells.

Phytol, SSADH inhibitory diterpenoid of Lactuca sativa

The succinic semialdehyde dehydrogenase (SSADH) inhibitory component was isolated from the EtOAc fraction of Lactuca sativa through repeated column chromatography; then, it was identified as phytol, a diterpenoid, based on the interpretation of several spectral data. Incubation of SSADH with the phytol results in a time-dependent loss of enzymatic activity, suggesting that enzyme modification is irreversible. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of 6.15 x 10(-2) mM(-1) min(-1). Complete protection from inactivation was afforded by the coenzyme NAD+, whereas substrate succinic semialdehyde failed to prevent the inactivation of the enzyme; therefore, it seems likely that phytol covalently binds at or near the active site of the enzyme. It is postulated that the phytol is able to elevate the neurotransmitter GABA levels in central nervous system through its inhibitory action on one of the GABA degradative enzymes, SSADH.

Limonoids and phytol derivatives from Cedrela sinensis

Two new compounds, cedrellin (1) and 2,6,10,15-phytatetraene-14-ol (2), together with five known compounds, 7 alpha-obacunyl acetate, 6-acetoxyobacunol acetate, 7 alpha-acetoxydihydronomilin, 2,6,10-phytatriene-1,14,15-triol and phytol were isolated from leaves of Cedrela sinensis. Their structures were elucidated on the basis of combined one- and two-dimensional spectral techniques.

Separation of stereoisomers in a simulated moving bed-supercritical fluid chromatography plant

The combination of two techniques, simulated moving bed (SMB) and supercritical fluid chromatography (SFC), leads to an apparatus with unique features. Besides the known advantages of the SMB process, like reduced solvent consumption and its continuity, the use of supercritical carbon dioxide as the mobile phase offers an easy product recovery by depressurizing the supercritical fluid. Details of a SMB-SFC plant are presented for the first time. Due to the large number of process parameters a simulation of the SMB process is necessary to achieve optimal operating conditions. The most important thermodynamic information for a SMB process is the adsorption isotherms. Therefore, isotherms for two phytol isomers are measured and correlated. A fast dynamic model for the simulation of SMB is used to calculate the region of complete separation taking different column configurations and the compressibility of the mobile phase into account.

Involvement of the mevalonic acid pathway and the glyceraldehyde-pyruvate pathway in terpenoid biosynthesis of the liverworts Ricciocarpos natans and Conocephalum conicum

The incorporation of 13C-labeled glucose into borneol, bornyl acetate, the sesquiterpenes cubebanol and ricciocarpin A, phytol, and stigmasterol has been studied in axenic cultures of the liverworts Ricciocarpos natans and Conocephalum conicum. Quantitative 13C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene building blocks of the sesquiterpenes and stigmasterol are built up via the mevalonic acid pathway, whereas the isoprene units of the monoterpenes and the diterpene phytol are exclusively derived from the glyceraldehyde-pyruvate pathway. These results indicate the involvement of both isopentenyl diphosphate biosynthetic pathways in different cellular compartments.

Antimycobacterial activity of (E)-phytol and derivatives: a preliminary structure-activity study

The crude methanol extract of the Kenyan shrub Leucas volkensii Gürke (Labiatae) displayed in a radiorespirometric bioassay antimycobacterial activity against Mycobacterium tuberculosis. Bioassay-guided fractionation of the crude extract led to the identification of (E)-phytol as the principal active component with a minimum inhibitory concentration (MIC) of 2 micrograms/ml, a value also observed for (3R,S,7R,11R)-phytanol, (Z)-phytol, and a commercially available 2:1 mixture of (E)- and (Z)-phytol. The derivatives (E)-phytol acetate, a mixture of the (2S,3S)- and (2R,3R)-isomers of (E)-phytol epoxide and (3R,S,7R,11R)-phytanic acid displayed lower activities with MICs of 8, 16, and > 128 micrograms/ml, respectively. Geraniol and farnesol, displayed MICs of 64 and 8 micrograms/ml, respectively. The activities of (E)-phytol, (Z)-phytol and (3R,S,7R,11R)-phytanol were found to be in the same range as ethambutol, a clinically useful drug with an MIC in the range 0.95-3.8 micrograms/ml.

A succinylanthranilic acid ester and other bioactive constituents of Jolyna laminarioides

Methyl 2-[propanamide-2'-methoxycarbonyl] benzoate, fucosterol, trans-phytol and p-formylphenol were isolated for the first time from a methanolic extract of Jolyna laminarioides. Methyl 2-[propanamide-2'-methoxycarbonyl]-benzoate exhibited chymotrypsin inhibitory activity and also found to be active against Escherichia coli and Shigella boydii. Fucosterol exhibited antifungal activity against Curvularia lunata, Stachybotrys atra and Microsporum canis.

Effects of olfactory stimulation with jasmin and its component chemicals on the duration of pentobarbital-induced sleep in mice

The effect of olfactory stimulation with jasmin and its component chemicals on pentobarbital sleep time was investigated using mice. In the present study we sought to determine which component of jasmin influences pentobarbital sleep time via olfactory stimulation. Sleep time was defined as the time elapsed between intraperitoneal pentobarbital administration and the first time that the animal was able to spontaneously right itself. Sleep time was significantly decreased by olfactory stimulation with jasmin, and also by one of the fractions obtained by fractional distillation at 150 degrees C and 0.1 mmHg. The fraction which influenced the sleep time was found to consist of benzyl benzoate, isophytol, geranyl linalool, phytol and phytyl acetate, which were identified using gas chromatography with mass and infrared spectrometry. In experiments using authentic samples of these components, phytol significantly shortened the pentobarbital sleep time, while the others had no effect. We conclude that phytol is the component of jasmin which reduces the duration of pentobarbital-induced sleep.