Synthesis of Phenolics and Flavonoids in Ginger (Zingiber officinale Roscoe) and Their Effects on Photosynthesis Rate

The relationship between phenolics and flavonoids synthesis/accumulation and photosynthesis rate was investigated for two Malaysian ginger (Zingiber officinale) varieties grown under four levels of glasshouse light intensity, namely 310, 460, 630 and 790 μmol m(-2)s(-1). High performance liquid chromatography (HPLC) was employed to identify and quantify the polyphenolic components. The results of HPLC analysis indicated that synthesis and partitioning of quercetin, rutin, catechin, epicatechin and naringenin were high in plants grown under 310 μmol m(-2)s(-1). The average value of flavonoids synthesis in leaves for both varieties increased (Halia Bentong 26.1%; Halia Bara 19.5%) when light intensity decreased. Photosynthetic rate and plant biomass increased in both varieties with increasing light intensity. More specifically, a high photosynthesis rate (12.25 μmol CO(2) m(-2)s(-1) in Halia Bara) and plant biomass (79.47 g in Halia Bentong) were observed at 790 μmol m(-2)s(-1). Furthermore, plants with the lowest rate of photosynthesis had highest flavonoids content. Previous studies have shown that quercetin inhibits and salicylic acid induces the electron transport rate in photosynthesis photosystems. In the current study, quercetin was an abundant flavonoid in both ginger varieties. Moreover, higher concentration of quercetin (1.12 mg/g dry weight) was found in Halia Bara leaves grown under 310 μmol m(-2)s(-1) with a low photosynthesis rate. Furthermore, a high content of salicylic acid (0.673 mg/g dry weight) was detected in Halia Bara leaves exposed under 790 μmol m(-2)s(-1) with a high photosynthesis rate. No salicylic acid was detected in gingers grown under 310 μmol m(-2)s(-1). Ginger is a semi-shade loving plant that does not require high light intensity for photosynthesis. Different photosynthesis rates at different light intensities may be related to the absence or presence of some flavonoid and phenolic compounds.     

HPLC测定金银忍冬叶、花、果实中绿原酸的含量

建立了反相高效液相色谱法测定金银忍冬叶、花和果实中的绿原酸含量的测定方法。利用超声波辅助提取金银忍冬叶、花和果实中的绿原酸,采用采用反相高效液相色谱法测定金银忍冬叶、花和果实中的绿原酸含量。结果表明:在流动相为甲醇(A)∶1.0%的冰醋酸溶液(B)=27∶73,色谱柱为Alltima C18Column(250 mm×4.6 mm,5μm),流动相流速为1.0 mL/min,检测波长为327 nm,柱温为25℃的实验条件下测定金银忍冬叶、花和果实中的绿原酸含量分别为:(31.64±2.21)mg/g,(17.45±1.05)mg/g,(5.14±1.39)mg/g,且宁夏金银忍冬植株不同部位中绿原酸类化合物的含量分布为:叶花果实。回收率为99.74%,RSD为0.23%。所建立的方法稳定,操作简单,结果可靠。     

Antioxidant activity of extracts of defatted seeds of niger (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>)

Niger (Guizotia abyssinica) seed was ground and then defatted with hexane. The meal remaining after oil extraction was tested as a source of antioxidants. Three solvent systems, A [80∶20 (vol/vol) ethanol/water], B [80∶20 (vol/vol) acetone/water], and C (water) were evaluated as extraction media. Crude extracts were examined for their antioxidant activity in a β-carotene-linoleate and a meat model system. Extract A exhibited superior antioxidant activity, compared to extracts B and C, and its composition was studied further by using column chromatography and HPLC. Four fractions (I–IV) were obtained, of which fractions III and IV showed activity in the β-carotene-linoleate model system. Fraction IV was also highly effective in scavenging the 2,2-diphenyl-1-picrylhydrazyl radical but was less active when used in a bulk oil model system. Preparative TLC showed fraction IV as consisting of two components. UV spectroscopy suggested that the major active component pressent was a chlorogenic acid-related compound. Furthermore, HPLC analysis established that chlorogenic acid was dominant in the free phenolics fraction (2.6 mg/g). Upon hydrolysis, however, a substantial amount of caffeic acid (42.8 mg/g) was released, presumably from esterified and glycosylated chlorogenic acid. Thus, niger extracts derive their antioxidant activity, at least in part, from the chlorogenic acid-related compounds.     

高效液相色谱法同时测定云南白花木瓜不同部位中5个成分的含量

建立了一种采用高效液相色谱(HPLC)法同时测定白花木瓜中绿原酸、芦丁、金丝桃苷、齐墩果酸、熊果酸的质量浓度的方法,比较了果皮、果肉中绿原酸、芦丁、金丝桃苷、齐墩果酸、熊果酸质量浓度的差异.结果显示,在以A相(甲醇)和B相(体积分数为16％乙腈,体积分数为0.3％磷酸水溶液)为流动相的梯度洗脱条件下,绿原酸、芦丁、金丝...     

Extraction and HPLC Characterization of Chlorogenic Acid from Tobacco Residuals

Abstract

Chlorogenic acid is a highly valuable natural polyphenol compound used in medicine and industries. Its current commercial sources are from plant extracts of Lonicera japonica Thunb and Eucommia ulmoides Oliver. These sources are limited and expensive. On the other hand, tobacco residuals contain chlorogenic acid and other natural polyphenol compounds. Large quantities of tobacco residuals are produced each year as waste materials from tobacco manufacturing, potentially providing an alternative commercial source of chlorogenic acid and other valuable compounds. In this paper, microwave and ultrasound extractions of chlorogenic acid with mixed solvent were studied. Total polyphenol concentrations in extract solutions obtained with different extraction methods were analyzed with the method of ferrous tartrate and UV‐Vis spectrophotometry and compared. The extraction solutions were also characterized for polyphenol compositions with the method of HPLC. Experimental results indicated that high extract concentrations of chlorogenic acid were obtained with a mixed solvent of acetone and water (1:2 v/v). A total polyphenol concentration of up to 4.87 mg/ml and a chlorogenic acid concentration of up to 2.12 mg/ml were achieved. The application of microwave and ultrasound significantly increased the extract concentrations. The extraction time needed was also much reduced. HPLC analysis indicated that acetone water mixed solvent extraction achieved much higher relative concentrations of chlorogenic acid to other compounds in the extract solutions. These results indicted that fast and effective extraction of chlorogenic acid from tobacco residuals were achieved.     

Chemical and experiential basis for rejection ofTropaeolum majus byPieris rapae larvae

Rejection of nasturtium,Tropaeolum majus, by cabbage-reared larvae ofPieris rapae has been explained by the presence of feeding deterrents in the nastrutium foliage. Sensitivity to the deterrents develops as neonate larvae feed on cabbage. The most prominent deterrent compound, which is present in nasturtium at a concentration of 40 mg/100 g fresh leaves, was identified as chlorogenic acid. When neonate larvae were fed on a cabbage leaf treated with high concentrations of deterrent-containing extracts of nasturtium foliage, they remained insensitive to the deterrents, so they accepted nasturtium when transferred as second instars. When neonate larvae were reared on a cabbage leaf treated with 0.1 mg chlorogenic acid, ca. 35% of the second instars accepted nasturtium. Similar dietary exposure of neonates to the subunits of chlorogenic acid, caffeic acid and quinic, acid resulted in much less or no effect on the rejection behavior of second instars. The results suggest that the combined effects of specific chemical constituents of nasturtium can explain the rejection of this plant by larvae ofP. rapae, but if larvae are continuously exposed to these compounds immediately after hatching, they apparently become habituated to the feeding deterrents. The lack of activity of the subunits of chlorogenic acid suggests that specific structural features are necessary for a dietary constituent to cause such habituation or suppression of sensitivity development.     

HPLC分析比较金银花花茎叶中绿原酸含量

目的：建立测定金银花中绿原酸含量的HPLC方法,并比较金银花花茎叶中绿原酸含量.方法：采用高效液相色谱法,色谱柱：Agilent Extend-C18（4.6 mm×150mm,5μm）,流动相：乙腈-水-磷酸（13∶87∶0.4）,流速1.0 mL/min,柱温25℃,检测波长为329 nm.结果：绿原酸在10.4～62.4 μg/mL内线性关系良好,平均回收率98.7％,RSD为1.74％.同时期的金银花花、茎、叶中绿原酸的含量分别为6.67％、5.43％、4.80％.结论：该方法精密、准确、快速、重现性好,可用来测定比较金银花花茎叶中绿原酸含量的方法,经HPLC法确定金银花花茎叶中均含有大量绿原酸,具有较高的开发利用价值.     

Antioxidant activity of mulberry fruit extracts

Phenolic compounds were extracted from the fruits of Morus nigra and Morus alba using methanol and acetone. The sugar-free extracts (SFEs) were prepared using Amberlite XAD-16 column chromatography. All of the SFEs exhibited antioxidant potential as determined by ABTS (0.75-1.25 mmol Trolox/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) (EC(50) from 48 μg/mL to 79 μg/mL), and reducing power assays. However, a stronger activity was noted for the SFEs obtained from Morus nigra fruits. These extracts also possessed the highest contents of total phenolics: 164 mg/g (methanolic SFE) and 173 mg/g (acetonic SFE). The presence of phenolic acids and flavonoids in the extracts was confirmed using HPLC method and chlorogenic acid and rutin were found as the dominant phenolic constituents in the SFEs.     

阴离子交换高效液相色谱法同时分离和分析三种氨基羧酸

建立了利用阴离子交换高效液相色谱同时分离分析甘氨酸、亚氨基二乙酸和氨三乙酸的方法。色谱柱为Sax强阴离子交换柱,用0.01 mol/L磷酸二氢钾缓冲液(pH=2.2)为流动相,紫外检测器波长为210 nm,对样品进行分析,并用外标法对这三种氨基羧酸进行定量。结果表明甘氨酸、亚氨基二乙酸和氨三乙酸分别在0.1024~2.0484 g/L、0.1006~2.0119 g/L、0.0050~0.3009g/L范围内线性关系良好(r>0.9995)。此法具有灵敏度高,线性相关系数和重现性好,流动相成本较低等特点。     

Effects of salicylic acid on growth and stomatal movements ofVicia faba L.: Evidence for salicylic acid metabolization

The influence of salicylic acid on the growth and stomatal movements ofVicia faba L. was investigated. Whereas shoot length, fresh weight, and transpiration rates, which are directly correlated with stomatal pore widths, were only affected at salicylic acid concentrations higher than 3.5 mM after long-term treatments, guard cells in epidermal peels exhibited a high sensitivity at concentrations as low as 0.001 mM, resulting in stomatal closing. HPLC analysis of methanolic extracts from roots and leaves revealed the presence of free salicylic acid and a metabolite, whose amount increased with time in plants previously incubated with a medium containing salicylic acid. The possible ability ofVicia faba to detoxify the phenolic acid may be one explanation of the discrepancy between the stomatal reaction in epidermal peels directly treated with the phenolic acid and after application through the transpiration stream. The results indicate that, under natural conditions, salicylic acid will not act as an allelopathic compound whose toxic properties severely affect the growth ofVicia faba.     

气相色谱-质谱联用定性全氟羧酸丁基酯

全氟羧酸化合物(PFCAs)作为全氟化合物(PFCs)其中的一种,具有了全部持久性有机污染物的特点:半挥发性、半衰期长、难降解、生物富集、较强毒性等。本实验应用离子对试剂四丁基硫酸氢铵(TBAHS),对PFC6A-PFC12A等七种全氟羧酸化合物进行离子对萃取,以及气相色谱进样口的衍生,在EI+全扫描的条件下对衍生产物进行了定性分析。结果表明:[C4H9]+m/z=57,[CF3]+m/z=69,[C2F4]+m/z=100,[C2F5]+m/z=119,[C3F5]+m/z=131,[C3F7]+m/z=169,[C4F7]+m/z=181,这几种碎片为所有全氟羧酸丁基酯的共有碎片,可对全氟羧酸丁基酯进行简单快捷的定性。     

Phenol Contents, Oxidase Activities, and the Resistance of Coffee to the Leaf Miner Leucoptera coffeella

We examined the role of phenolic compounds, and the enzymes peroxidase and polyphenol oxidase, in the expression of resistance of coffee plants to Leucoptera coffeella (Lepidoptera: Lyonetiidae). The concentrations of total soluble phenols and chlorogenic acid (5-caffeoylquinic acid), and the activities of the oxidative enzymes peroxidase (POD) and polyphenol oxidase (PPO), were estimated in leaves of Coffea arabica, C. racemosa, and progenies of crosses between these species, which have different levels of resistance, before and after attack by this insect. The results indicate that phenols do not play a central role in resistance to the coffee leaf miner. Differences were detected between the parental species in terms of total soluble phenol concentrations and activities of the oxidative enzymes. However, resistant and susceptible hybrid plants did not differ in any of these characteristics. Significant induction of chlorogenic acid and PPO was only found in C. racemosa, the parental donator of the resistance genes against L. coffeella. High-performance liquid chromatography (HPLC) analysis also showed qualitative similarity between hybrids and the susceptible C. arabica. These results suggest that the phenolic content and activities of POD and PPO in response to the attack by the leaf miner may not be a strong evidence of their participation in direct defensive mechanisms.     

Lipid Fractions,Fatty Acid Profiles,and Bioactive Compounds of Lithospermum officinale L. Seeds

Seeds of Lithospermum officinale L. from different climatic zones were analyzed for new sources of γ-linolenic acid (GLA, 18:3n-6) and stearidonic acid (SDA, 18:4n-3). Cultured Borago officinalis was also analyzed for comparative purposes. Analyses were conducted for fatty acid (FA) profiles of the glyceride oils from the seeds and in the neutral and polar lipids by gas chromatography (GC); lipid classes by open column chromatography and preparative thin layer chromatography (TLC); and tocopherols, sterols, and phenolic compounds by high-performance liquid chromatography with diode array detection (HPLC-DAD), and the later compounds were confirmed by liquid-chromatography-mass spectrometry (LC–MS). L. officinale from St. Petersburg Botanical Garden showed the highest percentage of GLA (17.9% of total FA), while wild-growing L. officinale from the Rostov region contained the highest percentage of SDA (17.2% of total FA). Total FA content ranged from 11.3 to 20.8% of seed weight. Neutral and polar lipids accounted for ~98 and 2.27%, respectively, of total lipids. Five neutral lipid classes were identified (% of NL): triterpene esters (1.3), triacylglycerols (93.1), free FA (1.8), diacylglycerols (1.4), and monoacylglycerols (2.4). The highest tocopherol content was found in samples from Chechen Republic (35.7 mg/100 g), in which the δ isomer was the main component. Samples from the Rostov region had the highest amounts of sterols (83.8 mg/100 g), and Δ⁵-avenasterol was the predominant compound in all samples. L. officinale seeds contain high amounts of phenolic compounds (389.9 mg/100 g as upper limit), in which rosmarinic acid is highlighted. Overall, all data suggest the possibility of using L. officinale seed oil in pharmaceutical and cosmetic formulae and as functional food.     

Application of High-Speed Counter-Current Chromatography Preparative Separation of Flavone C-Glycosides From Lophatherum gracile

Preparative high-speed counter-current chromatography (HSCCC) was used to separate and purify bioactive constituents from the stems and leaves of Lophatherum gracile Brongn. Six flavone C-glycosides each at over 95% purity including two new compounds were obtained in one-step separation by HSCCC with an optimized two-phase solvent system composed of ethyl acetate-n-butanol-ethanol-water at volume ratio of 4:2:1.5:8.5 (v/v/v/v). The experiment yielded 19.9 mg of luteolin 6-C-β-D-galactopyranosiduronic acid (1→2)-β-D-glucopyranoside (1), 28.5 mg of luteolin 6-C-α-L-arabinopyranosyl-7-O-β-D-glucopyranoside (2), 31.5 mg of isoorientin (3), 44.8 mg of orientin (4), 25.3 mg of swertiajaponin (5) and 12.1 mg of apigenin 6-C-β-D-galactopyranosiduronic acid (1→2)-β-D-glucopyranoside (6) from 500 mg of crude extracts. The purity of these compounds was determined by high-performance liquid chromatography (HPLC). Their chemical structures were identified by electron spray ionization mass spectroscopy (ESI-MS), ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR).     

高效液相色谱法测定化妆品中间苯二酚和水杨酸

采用高效液相色谱法同时测定化妆品中间苯二酚和水杨酸。色谱条件:Kromasil C8(250 mm×4.6 mm i.d.,5μm)色谱柱,以流动相甲醇+0.01 mol/L磷酸氢铵缓冲溶液进行梯度洗脱,流速1.0 mL/min,检测波长275 nm。结果表明,在此条件下间苯二酚和水杨酸均在0.5～150μg/mL内与相应的峰面积具有良好的线性关系(相关系数r分别为0.999 7和0.999 8),线性回归方程分别为A=12 420ρ-6 301和A=15 500ρ-8 810,回收率在95.9%～103.5%,RSD为0.61%～0.88%。     

反相高效液相色谱法测定化妆品中绿原酸的含量

建立了含金银花成分化妆品中绿原酸含量的测定方法。样品经甲醇提取后用反相高效液相色谱法进行测定。色谱柱为Athena C18-wp（250mm×4.6mm,5μm）,流动相为乙腈-0.1%磷酸溶液（13∶87）,检测波长327nm,流速1.0mL/min。绿原酸进样量在0.0020～0.1503μg范围内与峰面积线性关系良好,相关系数r〉0.9995,膏霜剂、水剂和乳液剂样品的平均回收率分别为91.3%、95.6%和102.3%,RSD分别为2.84%、0.66%和4.53%（n=6）。方法准确可靠、重复性好,可用于含金银花化妆品中绿原酸含量的检测。     

Phenolics and Antioxidant Activity of Mulberry Leaves Depend on Cultivar and Harvest Month in Southern China

To elucidate the effects of cultivar and harvest month on the phenolic content and antioxidant activity of mulberry leaves, four major phenolics, including chlorogenic acid (ChA), benzoic acid (BeA), rutin (Rut) and astragalin (Ast), were quantified using an HPLC-UV method. Leaves from six mulberry cultivars, collected from April to October, were analyzed. The antioxidant activity of mulberry leaves was assessed by ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging activity (HSA) and superoxide radical scavenging activity (SSA) assays. The results showed that the total values of the four phenolic compounds ranged from 2.3 dry weight (DW) to 4.2 mg/g DW, with ChA being the major compound. The mean total phenol (TP) content of the six cultivars ranged from 30.4 equivalents (GAE) mg/g DW to 44.7 GAE mg/g DW. Mulberry leaves harvested in May had the highest TP content. Moreover, the antioxidant activities of mulberry leaves harvested from April to October differed noticeably. In general, Kq 10 and May were considered to be a better cultivar and harvest month concerning phenolic content and antioxidant activity, respectively.     

Separation of Four Compounds from Forsythia suspensa by Counter-Current Chromatography with Stepwise Elution

High speed counter-current chromatography technique in preparative scale has been successfully applied to separate and purify main compounds from the ethyl acetate extract of Forsythia suspense using stepwise elution with two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (1:4:1:4,v/v) and (1:4:2:3,v/v). Under the optimized conditions, the preparative high-speed counter-current chromatography was performed on 350 mg of the ethyl acetate yielding phillyrin (12.8 mg), isolariciresinol-9’-O-β-D-glucopyranoside (5.3 mg), pinoresinol (21.2 mg), and phillygenin (8.3 mg) in a one-step separation, with purities over 90% as determined by HPLC. The structures of the separated compounds were identified by HPLC-MS and ¹H NMR.     

Allelopathic effect of alfalfa (Medicago sativa) on bladygrass (Imperata cylindrica)

Greenhouse and laboratory experiments were conducted at the Agricultural and Water Resources Research Center Station, Baghdad, in 1985 and 1986 to investigate the possible allelopathic potential of alfalfa (Medicago saliva L.) and its decomposed residues on bladygrass (Imperata cylin-drica L. Beauv.), a noxious weed in Iraq, and to isolate, characterize, and quantify possible allelopathic agents in alfalfa residues and root exudates. Results indicated that decomposed alfalfa roots and their associated soil produced a 51–56% reduction in bladygrass seed germination. Root and shoot length of bladygrass seedlings were reduced by an average of 88%. Decayed and undecayed mixtures of alfalfa roots and soil at 0.0151 (w/w) inhibited bladygrass seedlings reproduced from rhizomes by 30 and 42%. It was found that root exudates of alfalfa seedlings caused significant reduction in shoot and root dry weights of bladygrass seedlings when alfalfa and bladygrass were grown together in nutrient culture. Caffeic, chlorogenic, isochloro-genic,p-coumaric,p-OH-benzoic, and ferulic acids were detected in alfalfa root exudates and residues. The highest amount (126 fig phenolic acids/g soil) of these compounds was found in alfalfa root residues after six months of decomposition in soil.     

充气糖果中胭脂红酸的高效液相色谱测定

建立充气糖果中胭脂红酸的高效液相色谱方法。糖果经乙醇／氨杉水超声提取,水浴蒸至近干,氨水溶液定容。采用C18柱（4．6mm×250mm,5μm）,流动相为0．01％磷酸溶液和甲醇／乙腈,梯度洗脱,流速1．0mL/min,检测波长494nm。胭脂红酸在2．5—40．0mg／L线性良好,回收率为87％～102％,RSD为1．75％,检出限为0．3mg／kg。该方法操作简便、准确,适于充气糖果中胭脂红酸的测定。