Chemical Constituents of the Essential Oil from the Peel of Citrus bergamia Risso

The chemical components of the essential oil from the peel of Citrus bergamia Risso., which is first introduced successfully by us from abroad, were identified by GC-MS-DS technique, dual column retention index, and dual column authentic sample superimposition. The relative content of components of the essential oil, obtained by different methods, were measured. The experiment results indicated that the chemical components of the essential oil from the peel of Citrus bergamia Risso. are in agreement with values reported in articles abroad.     

巴柑檬果皮精油化学成分的研究

用 GC-MS-DS 联用技术、气相色谱双柱保留指数和气相色谱双柱标准品叠加实验,鉴定了我国首次引种成功的巴柑檬果皮精油的化学成分,测定了用不同方法提取的巴柑檬果皮精油各化学成分的相对含量。结果表明:引种的巴柑檬果皮精油的化学成分与国外文献值相符合。     

改良CTAB法提取番石榴叶片总DNA

目的:从番石榴叶片中快速提取高质量的总DNA。方法:改良CTAB法。主要改进之处在于不用液氮,而是直接研磨硅胶干燥样品;用高浓度CTAB、低浓度乙醇与NaCl盐析相结合等方法去除多糖。结果:应用改良后的方法可以快速提取番石榴叶片总DNA,有效去除组织中的多糖、蛋白质,抑制提取过程中的组织褐变。提取的DNA可用于限制性内切酶酶切和PCR扩增。结论:传统CTAB法经过改良,可用于快速提取番石榴高质量DNA。     

Repellent effect of guava leaf volatiles on settlement of adults of citrus psylla, Diaphorina citri Kuwayama, on citrus

Abstract  The Asiatic citrus psyllid ( Diaphorina citri Kuwayama [Hemiptera: Sternorrhyncha: Psyllidae]) is a vector of huanglongbing (citrus greening), a devastating disease of citrus caused by phloem-limited bacteria. Growing guava ( Psidium guajava ) as an intercrop appears to be a successful means of reducing psyllid numbers within citrus orchards; however, the mechanism by which such a reduction is achieved is unknown. To determine the repellent effect of guava leaf and factors attributed to this activity, responses of adult psyllids to guava leaf and its odor were evaluated in cage tests and Y-tube olfactometer test. The results showed that guava leaf possessed a repellent effect against the adult citrus psyllids. Fewer psyllids were found on citrus leaves in the presence of guava foliage than in its absence. Young and old guava leaf showed equal repellent activity. By covering the guava shoots with net cloth, it was revealed that the repellent effect of guava leaf against adult psyllids on citrus was attributed to the volatile compounds, rather than physical factors. The olfactometer response of adult psyllids to guava leaf odor was dosage-dependent. Between guava odor and control, only 35.00%, 25.00% and 16.25% of the psyllids moved toward guava odor when presented with 5.0, 10.0 and 15.0 g of guava shoots, respectively. The olfactometer experiments also showed that both male and female psyllids responded similarly to the guava leaf odor.     

番石榴多糖对糖尿病小鼠的血糖及胸腺、脾指数的影响

研究采用两种不同方法提取的番石榴多糖对四氧嘧啶致糖尿病的小鼠血糖值及胸腺、脾指数的影响。通过给小鼠腹腔注射四氧嘧啶(200 mg/kg BW)建立糖尿病小鼠模型,尾端取血,采用血糖仪分别在给小鼠灌胃多糖三天和十天后检测小鼠血糖值,第十天解剖小鼠,分别对小鼠胸腺和脾脏称重。结果表明:与糖尿病对照组比较,两组灌喂番石榴多糖的小鼠的生存质量提高,血糖值显著降低,同时胸腺指数显著增加,提示番石榴多糖具有降血糖作用,是一种潜在的糖尿病治疗药物。     

(1R,2S,6R)-Papayanal: a new male-specific volatile compound released by the guava weevil Conotrachelus psidii (Coleoptera: Curculionidae)

The guava weevil, Conotrachelus psidii is an aggressive pest of guava (Psidium guajava L.) that causes irreparable damages inside the fruit. The volatile compounds of male and female insects were separately collected by headspace solid-phase microextraction or with dynamic headspace collection on a polymer sorbent, and comparatively analyzed by GC–MS. (1R,2S,6R)-2-Hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane (papayanol), and (1R,2S,6R)-2,6-dimethyl-3-oxabicyclo[4.2.0]octane-2-carbaldehyde (papayanal) were identified (ratio of 9:1, respectively) as male-specific guava weevil volatiles. Papayanal structure was confirmed by comparison of spectroscopic (EIMS) and chromatographic (retention time) data with those of the synthetic pure compound. The behavioral response of the above-mentioned compounds was studied in a Y-tube olfactometer bioassay, and their role as aggregation pheromone candidate components was suggested in this species.     

Influence of Prohexadione-Calcium on the Growth and Quality of Summer ‘Jen-Ju Bar’ Guava Fruit

A 2-year trial was conducted to investigate the influence of prohexadione-calcium (ProCa) on the fruit quality of summer ‘Jen-Ju Bar’ guava (Psidium guajava L.). ‘Jen-Ju Bar’ trees were treated with various concentrations of ProCa: 0 (as control), 125, 250, and 500 mg L^?1, which significantly inhibited spring shoot growth. Summer guava fruits of the trees subjected to ProCa exhibited higher levels of total soluble solids and higher values of total soluble solids to titratable acidity ratio compared with control fruits. Summer guava fruits from trees treated with ProCa were firmer than those from untreated trees. ProCa sprays significantly affected pulp weight, core weight, pulp thickness, and pulp-to-core ratio. No other fruit quality characteristics were significantly affected by ProCa treatment.     

采收期对‘红心’番石榴品质和耐贮性的影响

以福建漳州栽培的‘红心’番石榴(Psidium guajava ‘Hongxin’)为材料,探究不同采收期对其果实采后耐贮性和品质的影响。实验分盛花期后95 d (采收期Ⅰ)、105 d (采收期Ⅱ)和115 d (采收期Ⅲ) 3个时段进行采收,采后果实在常温(25±1℃) 和相对湿度85%条件下贮藏,贮藏期间测定番石榴果实商品率、失重率、呼吸强度、相对电导率、色调角、硬度、可溶性固形物、可滴定酸、维生素C和总糖含量变化。结果表明,‘红心’番石榴果实采后软化迅速,颜色由绿转黄较快;随着采后贮藏时间的延长,番石榴果实的商品率、硬度、色调角、可滴定酸、维生素C和总糖的含量降低,而果实失重率、细胞膜相对透性增加;采收期Ⅰ较采收期Ⅱ、Ⅲ的耐贮性强。因此,对于‘红心’番石榴果实,考虑贮运期长,适宜在采收期Ⅰ采收;其他两个采收期可在产地销售。     

Metabolic and structural evidence for the existence of a third species of polyphosphoinositide in cells: D-phosphatidyl-myo-inositol 3-phosphate.

When human 1321 N1 astrocytoma cells were labelled to steady state with [3H]inositol and briefly with [32P]orthophosphate, a compound which contained both radiotracers and which co-migrated with phosphatidylinositol-myo-inositol 4-phosphate during t.l.c. could be extracted in acidic chloroform/methanol. Treatment with methylamine under conditions which lead to deacylation of conventional glycerophospholipids yielded a water-soluble moiety which was labelled with both radioisotopes and was eluted from an anion-exchange h.p.l.c. column with a retention time similar to, but distinct from, that of glycerophosphoinositol 4-phosphate. Experiments using sodium periodate and selective phosphatase enzymes to degrade this compound systematically generated a series of products which suggested the structure of the parent phospholipid was phosphatidyl-myo-inositol 3-phosphate (PtdIns3P). PtdIns3P is metabolically closely related to the pool(s) of inositol phospholipid(s) that serves as substrate(s) for an agonist-sensitive phosphoinositidase C, as the levels of PtdIns3P fell significantly when 1321 N1 cells were stimulated with carbachol. The relative rate of turnover of the inositol moiety of PtdIns3P is similar to that of both of the major polyphosphoinositides and significantly higher than that of total cellular phosphatidyl-myo-inositol. This suggests that all three polyphosphoinositides are synthesized from a common, rapidly metabolized, pool of phosphatidyl-myo-inositol.     

橘小实蝇植物源引诱活性物质的生物测定

植物源引诱物质可显著提高橘小实蝇Bactrocera dorsalis(Hendel)蛋白饵剂的应用效果,本文测试了柑橘、番木瓜、芒果、番石榴、杨桃的叶片浸提物、果实以及已知植物次生物质对橘小实蝇的引诱效果。植物浸提物的生物测定结果表明,杨桃的二氯甲烷浸提物的引诱效果最佳,平均引诱率为20.83%,对于不同的萃取剂而言,二氯甲烷、乙醇浸提物效果明显优于石油醚,三者浸提的平均引诱率分别为15.67%、15.17%和10.50%;对于不同寄主植物而言,柑橘浸提物的效果最佳,3种有机溶剂浸提物的平均引诱率为18.33%,其中石油醚、二氯甲烷和乙醇浸提物的引诱率分别为20.00%、15.83%和19.17%,其他植物浸提物的引诱效果为杨桃>番木瓜>芒果>番石榴,3种有机溶剂浸提物的平均引诱率分别为17.22%、11.67%、11.11%和10.56%。寄主果实的生物测定结果表明,柑橘的平均引诱率为65.83%,其中雌虫和雄虫的引诱率分别为61.67%和70.00%,明显高于杨桃、番石榴和番木瓜,三者的引诱率分别为31.67%、31.67%和21.67%,与柑橘引诱率差异显著(P<0.05)。已知植物次生物质的生物测定结果表明,甲基丁香酚的引诱效果最佳,平均引诱率为45.00%,其中雄虫和雌虫的引诱率分别为86.67%和3.33%;乙酸乙酯和番石榴香精的引诱效果次之,平均引诱率分别为32.50%和28.33%,其中雌虫的引诱率均为36.67%;杨桃香精和柠檬酸的引诱效果较差,平均引诱率分别为25.00%和26.67%。     

Host specificity of <Emphasis Type="Italic">Tectococcus ovatus</Emphasis> (Hemiptera: Eriococcidae), a potential biological control agent of the invasive strawberry guava, <Emphasis Type="Italic">Psidium cattleianum</Emphasis> (Myrtales: Myrtaceae), in Florida

Strawberry guava, Psidium cattleianum Sabine, is a woody tree or shrub native to coastal southeastern Brazil. Strawberry guava was introduced into Florida in the late 1800s as an ornamental species. The plant escaped cultivation and is invading natural areas throughout the southern half of the state. In addition to negative effects on Florida’s native ecosystems, strawberry guava also is a preferred host of the Caribbean fruit fly, Anastrepha suspensa Loew (Diptera: Tephritidae). In total, 57 plant species representing 21 families were included in the host range tests. First instar nymphs of Tectococcus ovatus Hempel fed on two closely related guava species, Brazilian guava (Psidium friedrichsthalianum O. Berg), and Costa Rican guava (Psidium guineense Sw.). However, none of the nymphs completed their development on these two non-target species. The results of the host specificity tests suggest that T. ovatus is a suitable candidate for classical biological control of strawberry guava in Florida.     

Performance of anaerobic contact filter in series for treating distillery spentwash

Investigations were carried out by using rigid polyurethane foam as a packing material in the anaerobic contact filter (series) to treat distillery spentwash. The effect of hydraulic retention time (HRT) in treatment efficiency of reactor (I) and (II) was evaluated at different initial substrate concentrations ranging from 1500 mg/l to 19,000 mg/l. The effect of toxic parameters such as sulphate present in the distillery spentwash and the corresponding parameters such as total sulphide and un-ionized hydrogen sulphide generated during digestion of wastewater were evaluated to assess the reactor performance. The results showed that at 4 d HRT the overall COD removal percent ranged from 98% to 73% for an influent COD of 1500 mg/l to 19,000 mg/l. The overall performance of COD removal percent in reactor (I) and (II) at 2, 3 and 4 d HRT's were investigated. At 3 d HRT the reactor (II) showed a higher COD removal percent when compared to reactor (I), which clearly shows the role of hydraulic retention time in degradation of the organic matter present in the wastewater above an influent COD concentration of 5000 mg/l.     

Determination of metformin in plasma by high-performance liquid chromatography after ultrafiltration

A rapid high-performance liquid chromatography (HPLC) method was developed for determination of metformin, an oral antidiabetic agent, in plasma. Sample preparation entailed a 30-min centrifugation of plasma through a micron filter with direct injection of the protein-free ultrafiltrate into an HPLC system consisting of a cation-exchange extraction column (7.5×4.6 mm), a column switching valve, and a cation-exchange analytical column (250×4.6 mm). The eluent was monitored at 232 nm. Metformin was well resolved at a retention time of about 5 min. There was less than 2% loss of metformin during ultrafiltration and good linearity was established from 0.10 to 40 mg/l of metformin hydrochloride. The lower limit of quantitation was about 0.05 mg/l, at which concentration the signal-to-noise was above 10. The intra- and inter-assay coefficients of variation at plasma concentrations of metformin hydrochloride between 0.25 and 25 mg/l were typically 0.8–1.4% and 3.5–6.4%, respectively. This method offers a rapid sample preparation time and achieves excellent sensitivity without resorting to extraction and evaporation techniques.     

Optimization and scale up of the adsorption fractionation of cod pyloric caeca deoxyribonuclease using axial and radial flow columns.

The key step in the purification of a deoxyribonuclease (DNase) from extracts of cod (Gadus morhua L.) pyloric caeca, is the selective retention of the enzyme by anion exchange chromatography. The cod DNase purification on Q-Sepharose Fast Flow (Pharmacia) was optimized, using a 60 ml fixed-bed column. In combination with titration curve analysis, we have screened the effect of buffer pHs, feed conductivity and protein loading, on the product recovery and purity. We have developed elution conditions which allow effective separation of the cod DNase from bounded impurities, such as proteinases and nucleic acids. Low levels of these impurities were regarded as essential for the desired product quality. The optimum resolution and maximum purification (ca. 20-fold increase in specific activity) of DNase, was, however, achieved at low protein loading (2.6 mg ml-1 gel), corresponding to less than 4% of the dynamic bed capacity. Scale-up to a 2.5 l pilot scale column (axial flow) and a 0.25 l radial flow column showed that the separation and yield obtained at laboratory scale was retained, and was independent of column geometry and bed height. The implications for a production scale scenario of 100 g of fractionated protein, are also discussed, as well as process hygiene. The optimization described herein adds further knowledge to the treatment of fish waste and the downstream processing of valuable biochemicals from marine raw material.     

The analysis of thiamin and its derivatives in whole blood samples under high pH conditions of the mobile phase

In this study a protocol for the analysis of thiamin and thiamin coenzymes in whole blood was developed. Thiamin and its coenzymes are analyzed by reversed phase liquid chromatography (RPLC), precolumn derivatisation with alkaline potassium ferricyanide and fluorescence detection, all at pH 10. Under these relatively high pH conditions the detectability of the analytes and the robustness of the method were substantially improved. The use of a high pH resistant RPLC column was a crucial step in developing this analysis method. Reproducibility, linearity, recovery, detection limit and column robustness were investigated. The within-batch CV was <2.5%, the between-batch CV <4.5%. The method was linear far above the physiological relevant concentration level. Recovery was almost 100% on an average. The limit of quantification was 1 nmol/l. The robustness of the RPLC column proved to be very high. Up to 1500 injections hardly any substantial changes in retention times and efficiency were observed. In summary: Using a high pH resistant RPLC column resulted in a robust, sensitive and precise method for the analysis of total Vitamin B1 and especially of TDP.     

Gas chromatographic profiling and pattern recognition analysis of urinary organic acids from uterine myoma patients and cervical cancer patients

An efficient organic acid profiling and pattern recognition method is described for the correlation between urinary organic acid profiles and uterine cervical cancer. After methoximation of keto acids in alkalinized urine samples, all free organic acids were recovered by a dual solid-phase extraction procedure, followed by conversion to tert.-butyldimethylsilyl derivatives for the profiling analysis by dual-capillary column gas chromatography (GC) with subsequent screening for acids by retention index (I) library matching. A total of 50 organic acids were positively identified in urine samples (0.25 ml) from 12 uterine myoma (benign tumor group) and 14 uterine cervical cancer (malignant tumor group) patients studied. When the GC profiles were simplified to their corresponding organic acid I spectra in bar graphical form, characteristic patterns were obtained for each average of benign and malignant tumor groups. Stepwise discriminant analysis performed on the GC data selected 16 acids as the variables discriminating between the two groups. Canonical discriminant analysis applied to these 16 variables correctly classified 26 urine samples into two separate clusters according to tumor types in the canonical plot.     

A new on-line dual enzymatic method for simultaneous quantification of cholesterol and triglycerides in lipoproteins by HPLC

We describe an on-line dual detection method using HPLC for lipoprotein analysis that allows simultaneous determination of cholesterol and triglyceride profiles from a single injection of sample. Two different gel permeation columns, TSKgel LipopropakXL and Superose 6HR, were applied to the dual detection system, evaluating analytical performance of the proposed method and the columns by analyzing serum samples from human and nonhuman subjects. Both TSK and Superose columns produced good within-day imprecision values less than 4.7% for cholesterol and 4.2% for triglyceride determination. Linear regression analysis showed the results from the Superose column (y) correlated well with those from the TSK column (x): y = 0.969x + 5.44 (r = 0.990) for total cholesterol (mg/dl), y = 1.08x - 11.14 (r = 0.985) for total triglycerides (mg/dl), and y = 1.093x - 0.06 (r = 0.978) for the ratios of triglycerides to cholesterol (mg/mg). Furthermore, the cholesterol and triglyceride profiles elucidated the differences in the resolution ability of the columns, which have not been apparent from a single lipid profile. We conclude that the dual detection concept with proper choice of column and enzymic reagents specific to the objectives of the particular study can facilitate studies of lipoprotein metabolism.     

Immunoaffinity extraction and tandem mass spectrometric analysis of human chorionic gonadotropin in doping analysis

A confirmatory and quantitative HPLC-tandem mass spectrometry (MS-MS) method for human chorionic gonadotropin hormone (hCG) at concentrations as low as 5 IU/l following immunoaffinity extraction of the glycoprotein from urine was developed. The extraction method involved retention of urinary hCG in the immunoaffinity column via specific antigen-antibody interaction. A variety of eluents were then used to quantitatively elute hCG from the immunoaffinity column. Qualitative and quantitative analysis of hCG were undertaken using MS-MS by identifying the amino acid sequence of the marker peptide betaT5 obtained from hCG by tryptic digestion and the peak areas of three product ions b(6)(+), b(9)(+) and y(11)(+), respectively.     

Silica retention in the Three Gorges Reservoir

A mass balance of dissolved silica (DSi) based on daily measurements at the inflow and outflow of the Three Gorges Reservoir (TGR) in 2007 and a more precise budget, with inflow, outflow, primary production, biogenic silica (BSi) settlement, dissolution of BSi in the water column and flux of DSi at the sediment–water interface in the dry season (April) of 2007 were developed. We address the following question: How much does the Three Gorges Dam (TGD) affect silica transport in the TGR of the Changjiang River (Yangtze River)? The DSi varied from 71.1 to 141 μmol/l with an average of 108 μmol/l, and it ranged between 68.1 and 136 μmol/l, with an average of 107 μmol/l in inflow and outflow, respectively, in the TGR in 2007. The linear relationship of DSi between inflow and outflow water is significant (r = 0.87, n = 362, p < 0.01). Along the main stream of the TGR, the DSi concentration decreases with an average concentration of 84.0 μmol/l in the dry season. However, the stratification of DSi was not obvious in the main channel of the TGR in the dry season. The BSi is within the range of 0.04–5.00 μmol/l, with an average concentration of 2.1 μmol/l in the main channel of the TGR, while it is much higher in Xiangxi Bay (1.30–47.7 μmol/l, 13.1 μmol/l) than in the main stream of the TGR and the other bays. After the third filling of the TGR, approximately 3.8% of the DSi was retained by the TGR based on a 12-month monitoring scheme in 2007, which would slightly reduce nutrient fluxes of the Changjiang River to the East China Sea (2%). DSi was lost during January to June and November, whereas the additions of DSi were found during the other months in 2007. The budget results also indicate that there is a slight retention of DSi. The retention of DSi in the reservoir is approximately 2.9%, while BSi is approximately 44%. Compared with the total silica load, the retention of DSi and BSi in the reservoir is only 5.0% in the dry season. With its present storage capacity, the reservoir does not play an important role as a silica sink in the channel of the TGR. The DSi load is significantly related to discharge both in inflow and outflow waters (p < 0.01). DSi retention, to some extent, is the runoff change due to impoundment.     

Hydroethanolic extract of Psidium guajava leaf for induced osteoarthritis using a guinea pig model

We investigated the therapeutic effects of an extract of Psidium guajava (guava) leaf on experimentally induced osteoarthritis in guinea pig. The left knee of 30 male guinea pigs was anesthetized and the cranial cruciate ligament was severed. The animals were followed for 8 weeks until osteoarthritis was confirmed by radiography and histopathology. Animals were divided randomly into five groups; group 1, the ligament was severed and untreated; group 2, the ligament was severed and treated with piascledine, an extract of soybean and avocado; group 3, the ligament was severed and treated with 200 mg/kg hydroethanolic extract of guava; group 4, the ligament was severed and treated with 400 mg/kg hydroethanolic extract of guava; and group 5, control animals without surgery or extracts. Radiological and histopathological evaluations after 8 weeks showed reduced severity of osteoarthritis in the piascledine treatment group compared to group 1. The guava extract also reduce the severity of osteoarthritis compared to controls. Histopathological examination of treatment and control groups showed that treatment the guava extract improved lesions significantly. Hydroethanolic extracts of guava leaf appears to prevent osteoarthritis by inhibition of free radical formation in the knee joint.