Joint transcriptomic and metabolomic analysis reveals the mechanism of low-temperature tolerance in Hosta ventricosa

Hosta ventricosa is a robust ornamental perennial plant that can tolerate low temperatures, and which is widely used in urban landscaping design in Northeast China. However, the mechanism of cold-stress tolerance in this species is unclear. A combination of transcriptomic and metabolomic analysis was used to explore the mechanism of low-temperature tolerance in H. ventricosa. A total of 12 059 differentially expressed genes and 131 differentially expressed metabolites were obtained, which were mainly concentrated in the signal transduction and phenylpropanoid metabolic pathways. In the process of low-temperature signal transduction, possibly by transmitting Ca²⁺ inside and outside the cell through the ion channels on the three cell membranes of COLD, CNGCs and CRLK, H. ventricosa senses temperature changes and stimulates SCRM to combine with DREB through the MAPK signal pathway and Ca²⁺ signal sensors such as CBL, thus strengthening its low-temperature resistance. The pathways of phenylpropanoid and flavonoid metabolism represent the main mechanism of low-temperature tolerance in this species. The plant protects itself from low-temperature damage by increasing its content of genistein, scopolentin and scopolin. It is speculated that H. ventricosa can also adjust the content ratio of sinapyl alcohol and coniferyl alcohol and thereby alter the morphological structure of its cell walls and so increase its resistance to low temperatures.When subjected to low-temperature stress, H. ventricosa perceives temperature changes via COLD, CNGCs and CRLK, and protection from low-temperature damage is achieved by an increase in the levels of genistein, scopolentin and scopolin through the pathways of phenylpropanoid biosynthesis and flavonoid biosynthesis.

Rapid Quantification and Validation of Biomarker Scopoletin in Paederia foetida by qNMR and UV-Vis for Herbal Preparation

Scopoletin has previously been reported as a biomarker for the standardization of Paederia foetida twigs. This study is the first report on the determination and quantification of scopoletin using quantitative nuclear magnetic resonance (qNMR) in the different extracts of Paederia foetida twigs. The validated qNMR method showed a good linearity (r² = 0.9999), limit of detection (LOD) (0.009 mg/mL), and quantification (LOQ) (0.029 mg/mL), together with high stability (relative standard deviation (RSD) = 0.022%), high precision (RSD < 1%), and good recovery (94.08–108.45%). The quantification results of scopoletin concentration in chloroform extract using qNMR and microplate ultraviolet-visible (UV-vis) spectrophotometer was almost comparable. Therefore, the qNMR method is deemed accurate and reliable for quality control of Paederia foetida and other medicinal plants without extensive sample preparation.

Time-resolved fluorescence and chemometrics-assisted excitation-emission fluorescence for qualitative and quantitative analysis of scopoletin and scopolin in Erycibe obtusifolia Benth

This paper presents a new strategy for qualitative identification of scopoletin and scopolin in Erycibe obtusifolia Benth using time-resolved (lifetimes) fluorescence and quantitative analysis with chemometrics-assisted excitation-emission matrix (EEM) fluorescence. Due to the significant spectral overlapping among analytes and interference, the use of the more selective time-resolved fluorescence is proposed for qualitative identification in quality control of traditional Chinese medicine (TCM) for the first time. Using the strategy of combining EEM fluorescence with second-order calibration method, i.e. parallel factor analysis (PARAFAC), the simultaneous quantification of scopoletin and scopolin in the complex system of Erycibe obtusifolia Benth was achieved successfully. The predicted concentrations were compared with the values obtained using high performance liquid chromatography-coupled to fluorimetric detector (HPLC-FLD), and no significant differences between them were observed. Therefore, the proposed methods using time-resolved fluorescence for qualitative analysis and EEMs coupled with second-order calibration for quantitative analysis in TCM are comparable and provide a suitable alternative to the chromatography-based method.

Simultaneous determination of umbelliferone and scopoletin in Tibetan medicine Saussurea laniceps and traditional Chinese medicine Radix angelicae pubescentis using excitation-emission matrix fluorescence coupled with second-order calibration method

A chemometrics-assisted excitation-emission matrix (EEM) fluorescence method is presented for simultaneous determination of umbelliferone and scopoletin in Tibetan medicine Saussurea laniceps (SL) and traditional Chinese medicine Radix angelicae pubescentis (RAP). Using the strategy of combining EEM fluorescence data with second-order calibration method based on the alternating trilinear decomposition (ATLD) algorithm, the simultaneous quantification of umbelliferone and scopoletin in the two different complex systems was achieved successfully, even in the presence of potential interferents. The pretreatment is simple due to the "second-order advantage" and the use of "mathematical separation" instead of awkward "physical or chemical separation". Satisfactory results have been achieved with the limits of detection (LODs) of umbelliferone and scopoletin being 0.06ngmL(-1) and 0.16ngmL(-1), respectively. The average spike recoveries of umbelliferone and scopoletin are 98.8±4.3% and 102.5±3.3%, respectively. Besides, HPLC-DAD method was used to further validate the presented strategy, and t-test indicates that prediction results of the two methods have no significant differences. Satisfactory experimental results imply that our method is fast, low-cost and sensitive when compared with HPLC-DAD method.

6-Methoxyflavonoids and Other Constituents from Microliabum polymnioides (Asteraceae)

The flower heads of Microliabum polymnioides afforded scopoletin, 5,4'-dihydroxy-3,6,7-trimethoxyflavone, 3,5,4'-trihydroxy-6,7-dimethoxyflavone and 3,5,7,4'-tetrahydroxy-6-methoxyflavone. The leaves contained hexadecanoic acid, phytol and docosane. This is the first report on the presence of 6-methoxyflavonoids in Microliabum genus.

[Determination of scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in plants of Erycibe]

OBJECTIVE

An accurate and reliable analytical method for-simultaneous determination of six active components (scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C) in plants of Erycibe was developed.

METHOD

Scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C in the samples were well separated in analytical HPLC by gradual elution with methanol-0.1% formic acid solution. The chromatographic condictions: Agilent Poroshell 120 EC-C18 column, flowing rate being 1 mL x min(-1), detecting wavelength at 345 nm.

RESULT

Good linearities of scopolin, chlorogenic acid, scopoletin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C were in the range of 0.026 8-2.68, 0.027 0-2.70, 0.008 1-0.81, 0.018 8-1.88, 0.017 6-1.76, 0.019 6-1.96 μg, respectively (r > 0.999 6). The average recoveries of the six components were 98.1%, 98.7%, 100.8%, 100.4%, 99.7%, 101.1%; the relative standard deviations were 2.67%, 2.86%, 2.62%, 1.98%, 2.76%, 2.19%.

CONCLUSION

The method is simple, feasible and reproducible and can be used for the quality control of plants of Erycibe.

Optimizing the models for rapid determination of chlorogenic acid, scopoletin and rutin in plant samples by near-infrared diffuse reflectance spectroscopy

Polyphenols in plant samples have been extensively studied because phenolic compounds are ubiquitous in plants and can be used as antioxidants in promoting human health. A method for rapid determination of three phenolic compounds (chlorogenic acid, scopoletin and rutin) in plant samples using near-infrared diffuse reflectance spectroscopy (NIRDRS) is studied in this work. Partial least squares (PLS) regression was used for building the calibration models, and the effects of spectral preprocessing and variable selection on the models are investigated for optimization of the models. The results show that individual spectral preprocessing and variable selection has no or slight influence on the models, but the combination of the techniques can significantly improve the models. The combination of continuous wavelet transform (CWT) for removing the variant background, multiplicative scatter correction (MSC) for correcting the scattering effect and randomization test (RT) for selecting the informative variables was found to be the best way for building the optimal models. For validation of the models, the polyphenol contents in an independent sample set were predicted. The correlation coefficients between the predicted values and the contents determined by high performance liquid chromatography (HPLC) analysis are as high as 0.964, 0.948 and 0.934 for chlorogenic acid, scopoletin and rutin, respectively.

[Study on quality standard of Chimonanthus nitens leaf]

OBJECTIVE

To set up the quality standard of Chimonanthus nitens leaf.

METHODS

Five compounds were identified by double-development thin layer chromatography, the plate was colorized with 1% vanillin-H2 SO4 solution and warmed up in 110 degrees C; The content of four compounds was determined by HPLC, the chromatography separation was performed on the Elite hypersil ODS2 (250 mm x 4.6 mm, 5 microm) column with gradient elution. The mixture of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min was used, the detection wavelength was 344 nm and the column temperature was set at 40 degrees C.

RESULTS

The TLC identification was highly specific and spots were clear. In HPLC method, the calibration curve was linear in the range of 5.665 - 56.65 microg/mL for scopoletin (r = 0.9999), the average recovery was 97.06% and RSD was 1.27%; The calibration curve was linear in the range of 2.4312 - 24.312 microg/mL for isofraxidin (r = 0.9999), the average recovery was 102.86% and RSD% was 0.93%; The calibration curve presented a linear range from 2.444 - 24.44 microg/mL for scoparone (r = 0.9999), the average recovery was 102.18% and RSD was 1.81%. The standard curve presented a linear range from 9.012 - 90.12 microg/mL for rutin (r = 0.9992), the average recovery was 104.44% and RSD was 4.2%.

CONCLUSION

These methods are reproducible, sensitive and simple and can be used to control the quality of Chimonanthus nitens leaf.

[Determination of chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near infrared spectroscopy]

The objective of the present study was to investigate the feasibility of predicting chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco by Fourier transform near-infrared (FT-NIR) spectroscopy. The partial least squares(PLS) regression method, second derivative and Norris derivative filter were applied in the NIR spectroscopy prediction of chlorogenic acid, rutin, scopoletin and total polyphenol in the range of 7 500 to 4 000 cm(-1). For chlorogenic acid, rutin, scopoletin and total polyphenol, the determination coefficients were 0.976 6, 0.941 9, 0.957 1 and 0.966 6, respectively. The SEP/SEC values for them were < 1.2, and the SD/SEP values for them were > 2. The root mean square error of cross validation (RMSECV) of the four calibration models were 1.938 9, 1.046 2, 0.047 9 and 2.745 2, respectively. NIR spectroscopy was compared with the conventional methods. The results show that the two methods showed no significant difference at the significant level of 0.05. NIR spectroscopy technology can accurately analyze chlorogenic acid, rutin, scopoletin and total polyphenol in tobacco.

[Study on chemical constituents of root bark of Discocleidion rufescens]

OBJECTIVE

To study the chemical constituents from root bark of Discocleidion rufescens.

METHODS

Column chromatography and spectral analysis were used to isolate and identify the constituents.

RESULTS

Ten compounds were obtained and identified from root bark of Discocleidion rufescens including beta-sitosterol (I), scopoletin (II), daucosterol (III), ricinine (IV), chrysophanol (V), aphyscion (VI), taraxerol (VII), pigenin (VIII), luteolin (IX), gallic acid (X).

CONCLUSION

Ten compounds are isolated for the first time from root bark of Discocleidion rufescens. The monomer of Compounds II is isolated from this genus for the first time.

Phenolic constituents of the Chilean herbal tea Fabiana imbricata R. et P

"Pichi" or "pichi romero" (Fabiana imbricata R. et. P., Solanaceae) is a Chilean plant used as a tea in the Andean regions of Chile and Argentina. A very simple and direct method was developed for the qualitative analysis of polyphenols in the tea by high-performance liquid chromatography (HPLC) with diode array detection and electrospray ionization tandem mass spectrometry. The phenolic constituents identified in the teas were chlorogenic acid (3-O-caffeoylquinic acid), p-hydroxyacetophenone, scopoletin and quercetin derivatives. The glycosides were mainly glucosides from p-hydroxyacetophenone and scopoletin while di- and tri-glycosides from quercetin were the main flavonoids. The content of the main phenolic compounds in the teas (g/100 g lyophilized infusion) was 0.8-1.9 % for scopoletin, 0.4-6.2 % for p-hydroxyacetophenone and 2.1-4.3 % for rutin, respectively. The health-promoting properties reported for this herbal tea can be associated with the presence of several phenolics with known antioxidant, diuretic and antiinflammatory activity.

Rapid and sensitive analysis of three polyphenols in tobacco by CE using homemade C(4)D with a mini detection cell

A rapid, sensitive, and practical CE with C(4) D detection was developed for the analysis of three polyphenols (rutin, scopoletin, and chlorogenic acid) in tobacco samples. The constructed mini detection cell (12 mm × 10 mm × 10 mm) of C(4) D featured with small inner cell volume (∼2 nL), smaller noise (<0.9 mV), repeatability, high strength and durableness. Three polyphenols were ultrasonically extracted with methanol-water (70:30, v/v) solution following SPE cleanup. The CE method was optimized with the running buffer of 150 mmol L(-1) 2-amino-2-methyl-1-propanol (pH 11.2), and the applied separation voltage of +20 kV over a capillary of 50 μm id × 375 μm od × 50 cm (38 cm to the C(4) D window, 41.5 cm to the UV detector window), which gave a baseline separation of three polyphenols within ca. 6 min. The method provided the limits of quantification (S/N = 10) at about 0.08-0.15 μg g(-1) for three polyphenols, whereas the overall recoveries ranged from 82% to 88%. The proposed method has been successfully applied to measure three polyphenols in the actual tobacco samples, and their contents were calculated and evaluated.

A 2-oxoglutarate-dependent dioxygenase from Ruta graveolens L. exhibits p-coumaroyl CoA 2'-hydroxylase activity (C2'H): a missing step in the synthesis of umbelliferone in plants

Coumarins are important compounds that contribute to the adaptation of plants to biotic or abiotic stresses. Among coumarins, umbelliferone occupies a pivotal position in the plant phenylpropanoid network. Previous studies indicated that umbelliferone is derived from the ortho-hydroxylation of p-coumaric acid by an unknown biochemical step to yield 2,4-dihydroxycinnamic acid, which then undergoes spontaneous lactonization. Based on a recent report of a gene encoding a 2-oxoglutarate-dependent dioxygenase from Arabidopsis thaliana that exhibited feruloyl CoA 6'-hydroxylase activity (Bourgaud et al., 2006), we combined a bioinformatic approach and a cDNA library screen to identify an orthologous ORF (Genbank accession number JF799117) from Ruta graveolens L. This ORF shares 59% amino acid identity with feruloyl CoA 6'-hydroxylase, was functionally expressed in Escherichia coli, and converted feruloyl CoA into scopoletin and p-coumaroyl CoA into umbelliferone with equal activity. Its bi-functionality was further confirmed in planta: transient expression of JF799117 in Nicotiana benthamiana yielded plants with leaves containing high levels of umbelliferone and scopoletin when compared to control plants, which contained barely detectable traces of these compounds. The expression of JF799117 was also tightly correlated to the amount of umbelliferone that was found in UV-elicited R. graveolens leaves. Therefore, JF799117 encodes a p-coumaroyl CoA 2'-hydroxylase in R. graveolens, which represents a previously uncharacterized step in the synthesis of umbelliferone in plants. Psoralen, which is an important furanocoumarin in R. graveolens, was found to be a competitive inhibitor of the enzyme, and it may exert this effect through negative feedback on the enzyme at an upstream position in the pathway.

Protective effect of fruits of Morinda citrifolia L. on scopolamine induced memory impairment in mice: a behavioral, biochemical and cerebral blood flow study

ETHNOPHARMACOLOGICAL RELEVANCE

Noni (Morinda citrifolia L.) is widely used for different illnesses including CNS disorders. Recently Noni has been reported to prevent amyloid beta induced memory impairment in mice. However, the influence of Noni on cholinergic system has not been explored so far. Therefore, present study was designed to investigate effect of Noni fruit on memory, cerebral blood flow (CBF), oxidative stress and acetylcholinesterase (AChE) activity in scopolamine induced amnesia model.

MATERIALS AND METHODS

Mice were orally treated with ethanolic extract of Noni fruit and chloroform, ethyl acetate and butanol fractions of ethanolic extract for three days. Scopolamine was administered 5 min prior to acquisition trial and memory function was evaluated by passive avoidance test. CBF was measured by laser doppler flowmetry. AChE activity and oxidative stress parameters were estimated in mice brain at the end of behavioral studies. Further, effect of ethanolic extract and its fractions (5-400 μg/ml) on AChE activity was measured in vitro.

RESULTS

Scopolamine caused memory impairment along with reduced CBF, increased AChE activity and oxidative stress in mice brain. Ethanolic extract of Noni fruits and its chloroform and ethyl acetate fractions significantly improved memory and CBF. However, butanol fraction had no effect. Further, increased oxidative stress and AChE activity following scopolamine was significantly attenuated by ethanolic extract of Noni and its fractions. Moreover ethanolic extract and its fractions showed dose dependent inhibition of AChE activity in vitro.

CONCLUSION

These observations suggest that Noni may be useful in memory impairment due to its effect on CBF, AChE and oxidative stress.

Changes in scopoletin concentration in cassava chips from four varieties during storage

BACKGROUND

The use of the root crop cassava (Manihot esculenta Crantz) is constrained by its rapid deterioration after harvesting. Chemical and spectroscopic examination earlier revealed the accumulation of the four hydroxycoumarins esculetin, esculin, scopolin and scopoletin derived from the phenylpropanoid pathway, during the time course of postharvest deterioration. In this investigation the scopoletin level in parenchymal samples of four cassava cultivars used in Benin, i.e. Kpaki kpika, Kpaki soan, Logoguesse kotorou and BEN 86052, was investigated by high-performance liquid chromatography (HPLC).

RESULTS

Presence was shown in all four varieties with a mean in fresh roots between 4.1 and 11.1 mg kg(-1) dry weight. A strong increase in the content of scopoletin was noticed after a peeling and drying process (6 days) for chip production, the mean content reaching 242.5 mg kg(-1) dry weight in the cultivar BEN 86052. After 3 months of storage this had decreased to 0.7 mg kg(-1) dry weight.

CONCLUSION

Strong accumulation of scopoletin in cassava roots used for chip production in Benin is followed by a decrease in its concentration.

Determination of active ingredients in mutouhui by capillary electrophoresis with electrochemical detection

Capillary zone electrophoresis with electrochemical detection has been used for the separation and determination of scopoletin, hyperin, chlorogenic acid, and quercetin in Mutouhui. The effects of several important factors, including running buffer acidity, separation voltage, and working potential, were evaluated to achieve the optimum conditions. The working electrode was a 300-microm carbon disk electrode at a working potential of + 0.95 V (versus saturated calomel electrode). Under the optimum conditions, the analytes can be well separated within 20 min in a 75-cm-long fused-silica capillary. The current response was linear over two orders of magnitude with detection limits (S/N = 3) ranging from 2.70 x 10(-8) g/mL to 1.30 x 10(-7) g/mL for all analytes. This method was used successfully in the analysis of Mutouhui, and the assay results were satisfactory.

Production of three O-methhylated esculetins with Escherichia coli expressing O-methyltransferase from poplar

O-Methyltransferase, POMT-9 was expressed in Escherichia coli. HPLC analysis of reaction products revealed three peaks corresponding to isoscopoletin, scopoletin, and scoparone, and their structures were determined using NMR. Biotransformation of esculetin with E. coli expressing POMT-9 generated scopoletin, isoscopoletin, and scoparone at 30.3, 21, and 31 microM respectively. POMT-9 is the first O-methyltransferase that produces three different O-methylated products.

Umbelliferone released from hairy root cultures of Pharbitis nil treated with copper sulfate and its subsequent glucosylation

Hairy root cultures of Pharbitis nil treated with CuSO4 and methyl jasmonate (MeJA) produced umbelliferone (1) and scopoletin (2) in the culture medium, and skimmin (3), a beta-D-glucopyranoside of 1, was isolated from the hairy roots. While 1 in the medium increased and reached a maximal level 16 h after the treatment with CuSO4, the amount of 3 in the hairy roots decreased, reaching a minimal level after 8 h, before recovering to a level higher than the basal level after 24 h and then continuously increasing. These observations suggest that 1 was released by the hydrolysis of 3. Umbelliferone (1) inhibited hairy root growth, while skimmin (3) did not. This result suggests that, after the release of 1 as a phytoalexin, the hairy roots glycosylated 1 for the detoxification and re-use of 3 as a source of phytoalexin.

[Determination of scopoletin and umbelliferone contents in Saussurea medusa Maxim by high-performance liquid chromatography]

The contents of scopoletin and umbelliferone in Saussurea medusa Maxim were determined by high-performance liquid chromatography (HPLC) using Merck Lichrospher100 RP-18e column (250 mm x 4.0 mm, 5 microm) with the mobile phase of methanol-tetrahydrofuran-water solution and the absorbance of the compounds observed at 346 nm. HPLC yielded an average recovery and RSD of 100.07% and 1.42% for scopoletin, and 99.41% and 2.06% for umbelliferone, respectively, suggesting that HPLC is a simple, rapid and accurate method for quality control of Saussurea medusa Maxim.

[Study on the constituents from Neonauclea sessilifolia]

Seven compounds were isolated from Neonauclea sessilifolia. They are paeonol, 3,4-dihydroxybenzoic acid, scopoletin, anthraquinnones chrysophanol, 4H-1-benzopyran-4-one,5,7-dihydroxy-2-methyl, beta-sitosterol and stigmasterol glucoside. These compounds were isolated at first time from this genus and this plant.

Use of environmental tobacco smoke constituents as markers for exposure

The 16-City Study analyzed for gas-phase environmental tobacco smoke (ETS) constituents (nicotine, 3-ethenyl pyridine [3-EP], and myosmine) and for particulate-phase constituents (respirable particulate matter [RSP], ultraviolet-absorbing particulate matter [UVPM], fluorescing particulate matter [FPM], scopoletin, and solanesol). In this second of three articles, we discuss the merits of each constituent as a marker for ETS and report pair-wise comparisons of the markers. Neither nicotine nor UVPM were good predictors for RSP. However, nicotine and UVPM were good qualitative predictors of each other. Nicotine was correlated with other gas-phase constituents. Comparisons between UVPM and other particulate-phase constituents were performed. Its relation with FPM was excellent, with UVPM approximately 1 1/2 times FPM. The correlation between UVPM and solanesol was good, but the relationship between the two was not linear. The relation between UVPM and scopoletin was not good, largely because of noise in the scopoletin measures around its limit of detection. We considered the relation between nicotine and saliva continine, a metabolite of nicotine. The two were highly correlated on the group level. That is, for each cell (smoking home and work, smoking home but nonsmoking work, and so forth), there was high correlation between average continine and 24-hour time-weighted average (TWA) nicotine concentrations. However, on the individual level, the correlations, although significant, were not biologically meaningful. A consideration of cotinine and nicotine or 3-EP on a subset of the study whose only exposure to ETS was exclusively at work or exclusively at home showed that home exposure was a more important source of ETS than work exposure.

Distribution of exposure concentrations and doses for constituents of environmental tobacco smoke

The ultimate goal of the research reported in this series of three articles is to derive distributions of doses of selected environmental tobacco smoke (ETS)-related chemicals for nonsmoking workers. This analysis uses data from the 16-City Study collected with personal monitors over the course of one workday in workplaces where smoking occurred. In this article, we describe distributions of ETS chemical concentrations and the characteristics of those distributions (e.g., whether the distribution was log normal for a given constituent) for the workplace exposure. Next, we present population parameters relevant for estimating dose distributions and the methods used for estimating those dose distributions. Finally, we derive distributions of doses of selected ETS-related constituents obtained in the workplace for people in smoking work environments. Estimating dose distributions provided information beyond the usual point estimate of dose and showed that the preponderance of individuals exposed to ETS in the workplace were exposed at the low end of the dose distribution curve. The results of this analysis include estimations of hourly maxima and time-weighted average (TWA) doses of nicotine from workplace exposures to ETS (extrapolated from 1 day to 1 week) and doses derived from modeled lung burdens of ultraviolet-absorbing particulate matter (UVPM) and solanesol resulting from workplace exposures to ETS (extrapolated from 1 day to 1 year).

Expression of uroporphyrinogen decarboxylase or coproporphyrinogen oxidase antisense RNA in tobacco induces pathogen defense responses conferring increased resistance to tobacco mosaic virus

Transgenic tobacco plants with reduced activity of either uroporphyrinogen decarboxylase or coproporphyrinogen oxidase, two enzymes of the tetrapyrrole biosynthetic pathway, are characterized by the accumulation of photosensitizing tetrapyrrole intermediates, antioxidative responses, and necrotic leaf lesions. In this study we report on cellular responses in uroporphyrinogen decarboxylase and coproporphyrinogen oxidase antisense plants, normally associated with pathogen defense. These plants accumulate the highly fluorescent coumarin scopolin in their leaves. They also display increased pathogenesis-related protein expression and higher levels of free and conjugated salicylic acid. Upon tobacco mosaic virus inoculation, the plants with leaf lesions and high levels of PR-1 mRNA expression show reduced accumulation of virus RNA relative to wild-type controls. This result is indicative of an increased resistance to tobacco mosaic virus. We conclude that porphyrinogenesis as a result of deregulated tetrapyrrole synthesis induces a set of defense responses that resemble the hypersensitive reaction observed after pathogen attack.

[Determination of total scopoletin in Caulis Erycibes by RP-HPLC]

OBJECTIVE

To accumulate data for quality control of Caulis Erycibes.

METHOD

The total-scopoletin in Caulis Erycibes was determined by RP-HPLC, using CLC-ODS1 column, 0.5% glacial acetic acid in methanol-water(26:55) as mobile phase and UV detector at 310 nm.

RESULT

The average recovery is 99.37% and RSD 0.39%.

CONCLUSION

Determination data have been obtained for fourteen batches of three species, and the contents of scopoletin should be no less than 30 mg/100 g.

[HPLC determination of five constituents in plants of genus Ligusticum]

A RP-HPLC method was established to separate and determine five constituents in plants of genus Ligusticum by using an ODS column (Hypersil-C18, 5 microns) and acetonitrile (containing 1.25% CHCl3)--water (saturated with CHCl3) as mobile phase for gradient elution. The five constituents were ferulic acid, scopoletin, 3-butyl-phthalide, ligustilide, and diligustide. They were detected at 284 nm. Peak purity was monitored by photodiode array detector. Benzthiazide was used as the internal standard. The method is simple, fast, sensitive and reproducible.

Exposure to environmental tobacco smoke in sixteen cities in the United States as determined by personal breathing zone air sampling

Approximately one hundred nonsmoking individuals in each of 16 metropolitan areas of the United States collected a sample of air from their breathing zone while in their workplace and a sample while away from work during their 24-hour days. Individuals were selected for the study in an attempt to equally represent those working and living in smoking and nonsmoking environments. Collected samples were analyzed for respirable particulate matter (RSP) (3.5 microns diameter), ultraviolet absorbing particulate matter, fluorescing particulate matter, solanesol, scopoletin, nicotine, 3-ethenyl pyridine, and myosmine. Individuals living and/or working in environments where smoking occurs were confirmed to be the most highly exposed to environmental tobacco smoke (ETS). Residential RSP levels ranged from 50 to 113% of those which have been reported by other investigators. For the majority of subjects who either lived or worked in smoking environments, the home was found to be the greater source of ETS exposure. Exposures of subjects whose spouses smoked unrestrictedly within the home were a factor of two to four higher than those of subjects who worked in locations where smoking occurred and was not restricted. Exposures of typical subjects to nicotine in the workplace were 30-60% of those estimated by the Occupational Safety and Health Administration (OSHA) and 15-20% of those estimated by the OSHA for the most highly exposed workers.

Differentiation of cytochrome P-450 activities with scoparone as substrate. A rapid one-step HPLC-analysis

A direct and highly sensitive high performance liquid chromatography (HPLC) method for measuring cytochrome P-450 activities in biological probes, with the substrate scoparone, is described. Using 10-100 microliter of a supernatant of an incubation mixture of scoparone (0.1 mmol/l), microsomal fractions (1 nmol P-450/ml), MgCl2 (2 mmol/l), and NADPH (4 mmol/l), the products scopoletin and isoscopoletin as well as the substrate scoparone were separated by HPLC on an ODS-Hypersil RP-18 column. The compounds were detected by a UV-spectrophotometer (345 nm) and quantified by the aid of an external calibration curve. The limits of detection were 10 pmol for the products scopoletin and isoscopoletin. This method allows the direct quantification of P-450 activities and the simultaneous differentiation between "3-methylcholanthren-like" or "phenobarbital-like" induction states by estimation of the scopoletin: isoscopoletin ratios.

Liquid chromatographic determination of scopoletin in hydroalcoholic extract of oak wood and in matured distilled alcoholic beverages

A liquid chromatographic (LC) method is described for determination of the coumarins esculin, umbelliferone, scopoletin, and 4-methyl umbelliferone in hydroalcoholic extracts of oak wood and in matured distilled alcoholic beverages. Samples were injected directly into the LC column (30 cm, 5 micron C18) and detected by fluorescence detector. Under these experimental conditions, only scopoletin (detection limit, 200 pg) was found in hydroalcoholic oak wood extracts and in spirits matured in oak wood. Applications of this method to spirits distilled from wine, grain, and sugar cane aged in oak barrels showed that amounts varied from 0.026 to 1.57 ppm.

[Studies on enzymic browning of potatoes (Solanum tuberosum). I. Phenoloxidases and phenolic compounds from different varieties (author's transl)]

31 samples of potato varieties with slow, medium and fast rates of browning were studies. Characteristic enzyme patterns were obtained from polyacrylamide gel electrophoresic of the phenoloxidases of varieties with different discolouration rates. The differences lie mainly in the intensities of the enzyme bands. The qualitative determinaiton of the phenols showed no significant differences. Tyrosine, chlorogenic acid and caffeic acid produce coloured oxidation products; the characteristic colour gradations of in vivo browning were only observed in the presence of tyrosine. It is concluded that the same reactions take place during the discolouration of all the varieties.