Production and structural analysis of PP-V, a homologue of monascorubramine, produced by a new isolate of Penicillium sp

A fungal strain newly isolated from soil has been found to produce a violet water-soluble pigment (PP-V) in high quantity when cultured in a medium consisting of soluble starch and citrate buffer. Glucose repressed the production of this pigment. PP-V has the molecular formula C23H25NO6 revealed by HR-FAB mass spectroscopy and has been shown to be composed of an isoquinoline skeleton, a n-octanoyl group, and a 2-propenoic acid group by NMR. In conclusion, PP-V is a novel compound, 3-(9a-methyl-3-octanoyl-2,9-dioxo-2,7,9,9a-tetrahydro-furo[3,2-g]isoquinolin-6-yl)acrylic acid; a homologue of monascorubramine in which the 1-propenyl group is converted to a 2-propenoic acid group.     

Kinetic resolution of an indan derivative using Bacillus sp. SUI-12: synthesis of a key intermediate of the melatonin receptor agonist TAK-375

The chiral indan derivative (S)-2 (2-[(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl-amine) was synthesized by enzyme-catalyzed asymmetric hydrolysis of the racemic acetamide 1 (N-[2-(1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl)ethyl]acetamide). The reaction was carried out using Bacillus sp. SUI-12 screened for the ability to hydrolyze 1 to give (S)-2 with high enantioselectivity. In a scaled-up experiment, a low reaction rate was observed. However, by changing the culture medium and the reaction conditions, it became possible to run the reaction to 40% conversion on a 10-g or more scale, obtaining (S)-2 at >;99% enantiomeric excess (ee). The (S)-2 obtained was available for the synthesis of the melatonin receptor agonist TAK-375 (N-[2-[(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl]propanamide).     

A strong antioxidant isolated from grapefruit juice retentate

A new furanocoumarin, 4-hydroxy-9-(3,7-dimethylocta-1,6-dien-3-yl)-7H-furo [3,2-g] chromen-7-one (for convenience, temporarily designated as GF-338), was isolated and characterized from grapefruit juice retentate using different chromatography and spectra techniques. At the final concentration of 10 μmol/L in the reaction system, GF-338 showed 8.53±0.35% 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging activity while Vitamin C only showed 4.32±0.25%, which demonstrated that GF-338 is a potential strong antioxidant. Its other bioactivities remain to be evaluated.     

Biosynthesis of PP-V, a monascorubramine homologue, by Penicillium sp. AZ

The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by 13C-labeling studies. The [1-13C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-13C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin.     

PP-R, 7-(2-hydroxyethyl)-monascorubramine, a red pigment produced in the mycelia of Penicillium sp. AZ

A red pigment was extracted and purified from the mycelia of a newly isolated strain of Penicillium sp., Penicillium sp. AZ, which produced a soluble violet pigment PP-V, 12-carboxyl-monascorubramine, in the culture fluid. The red pigment, PP-R, was determined by FAB-MS and 1H and 13C NMR to be a novel compound, 7-(2-hydroxyethyl)-monascorubramine.     

Biosynthesis of PP-V, a monascorubramine homologue, by Penicillium sp. AZ

The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by ¹³C-labeling studies. The [1-¹³C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-¹³C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin.     

Terpenoids and hexenes from the leaves of Crataegus pinnatifida

Crataegus pinnatifida have long been used in traditional Chinese medicine and European herbal medicine, and are widely consumed as food, in the form of juice, drink, jam and canned fruit. Four new compounds, a sesquiterpene and its glycoside (1–2), two monoterpene glycosides (3–4), together with eight known compounds (5–12), were isolated from the leaves of C. pinnatifida. Their structures were elucidated as (5Z)-6-[5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-ol (1), (5Z)-6-[5-(2-O-β-d-glucopyranosyl-propan-2-yl)-2-methyl tetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-ol (2), 5-ethenyl-2-[2-O-β-d-glucopyranosyl-(1″ → 6′)-β-d-glucopyranosyl-propan-2-yl]-5-methyltetrahydrofuran-2-ol (3), 4-[4β-O-β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranosyl-2,6,6-trimethyl-1-cyclohexen-1-yl]-butan-2-one (4), (Z)-3-hexenyl O-β-d-glucopyranosyl-(1″ → 6′)-β-d-glucopyranoside (5), (Z)-3-hexenyl O-β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranoside (6), (Z)-3-hexenyl O-β-d-rhamnopyranosyl-(1″ → 6′)-β-d-glucopyranoside (7), (3R,5S,6S,7E,9S)-megastiman-7-ene-3,5,6,9-tetrol (8), (3R,5S,6S,7E,9S)-megastigman-7-ene-3,5,6,9-tetrol9-O-β-d-glucopyranoside (9), (6S,7E,9R)-6,9-dihydroxy-4,7-megastigmadien-3-one 9-O-[β-d-xylopyranosyl-(1″ → 6′)-β-d-glucopyranoside] (10), Linarionoside C (11), and (3S,9R)-3,9-dihydroxy-megastigman-5-ene 3-O-primeveroside (12), using a combination of mass spectroscopy, 1D and 2D NMR spectroscopy and chemical analysis. Cytotoxicity of the new compounds was assayed against selected human glioma (U87) cell lines.     

基于十二碳烯醛的番茄红素全合成

以6,10-二甲基-3,5,9-十一烷三烯-2-酮(8)与亚甲基二磷酸四乙酯(7)经Wittig-Horner反应得到2,6,10-三甲基-1,3,5,9-四烯十一烷基膦酸二乙酯(9);以E-2-丁烯-1,4-二膦酸二乙酯(2)与4,4-二甲氧基-2-丁酮(3)通过Wittig-Horner反应和水解反应合成化合物3,8-二甲基-3,5,7-辛三烯-1,10-二醛(5),2,6,10-三甲基-1,3,5,9-四烯十一烷基膦酸二乙酯(9)与3,8-二甲基-3,5,7-辛三烯-1,10-二醛(5)通过Wittig-Horner反应得到目标产物番茄红素(10),并采用核磁共振(NMR)、质谱(HRMS/GC-MS)和红外光谱(IR)进行结构验证。结果表明,合成的番茄红素总产率为16.7%。     

Studies on melanoidin-type colorants generated from the Maillard reaction of protein-bound lysine and furan-2-carboxaldehyde – chemical characterisation of a red coloured domaine

 The identification of a coloured substructure of melanoidin-type colorants is reported in the present paper. Brown-orange melanoidins with mass >10000 daltons were isolated from a thermally treated aqueous solution of casein and furan-2-carboxaldehyde using ultracentrifugation. After complete enzymatic digestion of the protein skeleton, two intense red coloured compounds were detected in the melanoidin hydrolysate by HPLC. These compounds were identified as the previously unknown chromophoric amino acid (S)-2-amino-6-{4-[(E)-1-formyl-2-(2-furyl)ethenyl]-5-(2-furyl)-2-[(E)-(2-furyl) methylidene]-2,3-dihydro-3-oxo-1H-pyrrol-1-yl}hexanoic acid and its 2-[(Z)-(2-furyl)methylidene] isomer, by using several NMR techniques, by MS, UV, and IR spectroscopy. The identification of these novel compounds verifies the idea that melanoidin-type colorants can be generated by a cross-linking reaction between a low molecular weight chromophore and a non-coloured high molecular weight biopolymer. Received: 19 August 1997 / Revised version: 24 October 1997     

Adsorption and uptake of Cu by Emiliania huxleyi in natural seawater

Short-term kinetic experiments, carried out in natural coastal seawater (with predetermined background levels of trace metals and organic ligands, L) enriched with nitrate and phosphate, demonstrated that Emiliania huxleyi was able to uptake Cu very quickly. After 10 min of exposure (background Cu level in the inoculated cells: [Cu]total cellular = 9.3 x 10(-17) mol cell-1, [Cu]intracellular = 8.4 x 10(-17) mol cell-1, and [Cu]extracellular = 1.0 x 10(-17) mol cell-1) to a natural seawater which contained 29 nM total initial dissolved Cu concentration ([Cu]d) (29 nM [CuL] and 3.2 x 10(-13) M free Cu concentration, [Cu2+]) the intracellular Cu was already 28 x 10(-17) mol cell-1. This value corresponded to 85% of the intracellular metal observed in pseudoequilibrium conditions (after 24 h of exposure) and to 88% of the total metal sorption (adsorption plus uptake) after 10 min. In contrast, the external adsorption after 10 min was only 3.0 x 10(-17) mol cell-1 which corresponded to 60% of the extracellular metal in pseudoequilibrium conditions. Simultaneously occurred a very fast release of organic ligands (L) by E. huxleyi, the majority being identified by cathodic stripping voltammetry as glutathione. The production of exudates increased with both Cu concentration and exposure time. After 10 min of exposure, the production of exudates in a medium with 129 nM [Cu]d (72 nM [CuL] and 7.9 x 10(-13) M [Cu2+]) was 51 nM, about 42% of that observed in pseudoequilibrium. As the Cu complexes with the organic ligands present in the medium were very stable (logarithm of the conditional stability constant: 12.18 +/- 0.06) and the ligand concentration in the medium was relatively high (e.g. 123 nM CL in the medium with 129 nM initial [Cu]d after 10 min of exposure) most of the metal was organically bound in the medium.     

Studies on melanoidin-type colorants generated from the Maillard reaction of protein-bound lysine and furan-2-carboxaldehyde – chemical characterisation of a red coloured domaine

 The identification of a coloured substructure of melanoidin-type colorants is reported in the present paper. Brown-orange melanoidins with mass >10000 daltons were isolated from a thermally treated aqueous solution of casein and furan-2-carboxaldehyde using ultracentrifugation. After complete enzymatic digestion of the protein skeleton, two intense red coloured compounds were detected in the melanoidin hydrolysate by HPLC. These compounds were identified as the previously unknown chromophoric amino acid (S)-2-amino-6-{4-[(E)-1-formyl-2-(2-furyl)ethenyl]-5-(2-furyl)-2-[(E)-(2-furyl) methylidene]-2,3-dihydro-3-oxo-1H-pyrrol-1-yl}hexanoic acid and its 2-[(Z)-(2-furyl)methylidene] isomer, by using several NMR techniques, by MS, UV, and IR spectroscopy. The identification of these novel compounds verifies the idea that melanoidin-type colorants can be generated by a cross-linking reaction between a low molecular weight chromophore and a non-coloured high molecular weight biopolymer. Received: 19 August 1997 / Revised version: 24 October 1997     

Synthesis of Low Molecular Weight Flavor Esters Using Plant Seedling Lipases in Organic Media

Powders from germinated seedlings of wheat, barley, rapeseed, maize, and linola synthesized low molecular weight flavor esters in an organic medium (hexane). Direct esterification of acetic, butyric, and caproic acids, with ethanol, butanol, isopentanol, or (Z)-3- hexen-l-ol was achieved. Of the systems examined, germinated rapeseed showed the highest degree of flavor synthesis. (Z)-3-hexen-1-yl butyrate and (Z)-3-hexen-1-yl caproate were produced with yields of about 96%. Butyl butyrate, isopentyl butyrate, butyl caproate and isopentyl caproate were produced at 80% yield. Linola seedling powder gave yields of ≤63% for ethyl acetate and butyl acetate. More moderate (40%) yields were obtained with barley and maize seedling powders. Rapeseed seedling powder is a convenient and inexpensive catalyst for preparing low molecular weight esters in organic medco.     

萎凋时间对“英红九号”白茶香气的影响

采用顶空固相微萃取和气相色谱-质谱联用法,分析不同萎凋时间"英红九号"白茶香气化合物的组成及含量。结果表明,"英红九号"白茶的香气总量随萎凋时间的延长呈现先增后降趋势,萎凋24 h含量最高,达到858.40 ng/g。白茶香气主要由醇类、酯类、醛类、酮类和烃类组成,其中醇类化合物所占比例最大。不同萎凋时间白茶的香气化合物组成比较相似。顺-3-己烯-1-醇、芳樟醇、乙酸-顺-3-己烯酯、丁酸-顺-3-己烯酯、水杨酸甲酯、己酸-顺-3-己烯酯、己醛、苯甲醛、反,反-2,4-庚二烯醛、壬醛、反,反-3,5-辛二烯-2-酮、3,5-辛二烯-2-酮、β-紫罗兰酮、β-香叶烯、柠檬烯、反-β-罗勒烯和β-罗勒烯,这17种香气化合物在多数样品中含量较高,其含量总和占各样品香气总量的67.3%~76.0%,对香气总量变化影响较大;其中芳樟醇、水杨酸甲酯等多数化合物含量随着萎凋进行先增后降;而苯甲醛和β-香叶烯含量在30 h的萎凋过程中总体持续上升。     

抗癌药物拉帕替尼两个杂质的合成

目的合成抗癌药物拉帕替尼的两个杂质。方法以N-[3-氯-4-[(3-氟苄基)氧基]苯基]-6-碘喹唑啉-4-胺为起始原料,经Suzuki偶联反应,得到N-[3-氯-4-[(3-氟苄基)氧基]苯基]-6-[(5-甲酰基)呋喃-2-基]-4-喹唑啉胺,直接与还原剂NaBH(OAc)3反应,得到特定杂质N-[3-氯-4-[(3-氟苄基)氧基]苯基]-6-(5-羟甲基呋喃-2-基)-4-喹唑啉胺;起始原料经Suzuki反应后,与2-甲砜基乙胺反应,在NaBH(OAc)3作用下得粗品,经制备液相分离,得到另一特定杂质双[[5-[4-[[3-氯-4-[(3-氟苄基)氧基]苯基]氨基]喹唑啉-6-基]呋喃-2-基]甲基][2-(甲磺酰基)乙基]胺。结果两个目标物经质谱(MS),核磁共振氢谱(1H NMR)确证其化学结构。结论合成的两个杂质可作为拉帕替尼质量控制对照品,本工艺操作可行,原料易得。     

Production of recombinant protein by baculovirus-infected insect cells in immobilized culture using porous biomass support particles

Immobilization of insect cells using porous biomass support particles (BSPs) and production of a recombinant protein by the immobilized cells after infection with a baculovirus were investigated in a shake-flask culture. Sf9 cells were passively immobilized in reticulated polyvinyl formal (PVF) resin BSPs (2 x 2 x 2 mm cubes) with matrices of 60 mum mean pore diameter in situ in shake-flasks. The cell density in the BSPs was over 5 x 10(7) cells/cm3-BSP in cultures with regular replacement of the culture medium, as estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. After infection with a recombinant baculovirus carrying the beta-galactosidase gene, immobilized cells within the BSPs showed a high specific productivity, comparable to the maximum productivity in shake-flask cultures of non-immobilized cells, as long as nutrients in the medium were not depleted. Even when immobilized cells at a high density of 5 x 10(7) cells/cm3-BSP were infected with the baculovirus, efficient beta-galactosidase production with a high specific productivity was possible by replacing the medium at appropriate intervals to avoid nutrient depletion.     

Estimation of primary and secondary particulate matter intake fractions for power plants in Georgia

Air pollution benefit-cost analyses depend on dispersion models to predict population exposures to pollutants, but it is difficult to determine the reasonableness of the model estimates. This is in part because validation with field measurements is not feasible for marginal concentration changes and because few models can capture the necessary spatial and temporal domains with adequate sophistication. In this study, we use the concept of an intake fraction (the fraction of a pollutant or its precursor emitted that is eventually inhaled) to provide insight about population exposures and model performance. We apply CALPUFF, a regional-scale dispersion model common in health benefits assessments, to seven power plants in northern Georgia, considering both direct emissions of fine particulate matter (PM2.5) and secondarily formed ammonium sulfate and ammonium nitrate particles over a domain within 500 km of Atlanta. We estimate emission-weighted average intake fractions of 6 x 10(-7) for primary PM2.5, 2 x 10(-7) for ammonium sulfate from SO2, and 6 x 10(-8) for ammonium nitrate from NOx, with no effect of SO2 on ammonium nitrate. To provide insight about model strengths and limitations, we compare our findings with those from a frequently applied source-receptor (S-R) matrix. Using S-R matrix over an identical domain, the corresponding intake fractions are 5 x 10(-7), 2 x 10(-7), 3 x 10(-8), and -2 x 10(-8), respectively, with the values approximately doubling if the domain is expanded to cover the continental United States. Evaluation of model assumptions and comparison of past intake fraction estimates using these two models illustrates the importance of assumptions about the relative concentrations of ammonia, sulfate, and nitrate, which significantly influences ammonium nitrate intake fractions. These findings provide a framework for improved understanding of the factors that influence population exposures to particulate matter.     

吹扫捕集GC/MS法测定紫苏不同变种叶片中的挥发性成分

采用吹扫捕集技术对紫苏不同变种叶片中的挥发性成分进行富集,以气质联用仪(GC-MS)进行鉴定,运用面积归一化法确定各组分的相对含量。结果表明,分别属于紫苏属植物3 个变种的4 份试材之间叶片挥发油的组分和相对含量差异显著。4 份紫苏试材共检测出31 种挥发油成分,但其共有的成分仅有顺-3- 己烯醛、石竹烯和圣亚麻三烯3 种。野生紫苏变种的主要成分是柠檬烯(77.90%)、石竹烯(14.33%)、顺-3- 己烯醛(4.9%)、胡椒酮(1.71%),回回苏变种的主要成分是石竹烯(30.65 %)、柠檬烯(24.60%)、顺-3- 己烯醛(21.82%)、紫苏醛(17.70%),紫苏变种1(来源于河北安国市)的主要成分是5- 乙叉-1- 甲基- 环庚烯(52.79%)、顺-3- 己烯醛(19.98%)、石竹烯(13.60%)、紫苏醛(9.46%),紫苏变种2(来源于广西灵山县)的主要成分是紫苏醛(31.86%)、5- 乙叉-1- 甲基- 环庚烯(31.68%)、顺-3- 己烯醛(21.50%)、石竹烯(10.47%)。     

Night-time atmospheric fate of acrolein and crotonaldehyde

The absolute rate coefficients for the gas-phase reaction of the NO3 radical with acrolein and crotonaldehyde have been measured overthe temperature range 249-330 K, using a discharge flow system and monitoring the NO3 radical by laser induced fluorescence (LIF). The obtained rate coefficients at 298 K for NO3 reactions with acrolein and crotonaldehyde were (3.30 +/- 0.39) x 10(-15) cm3 molecule(-1) s(-1) for acrolein and (1.35 +/- 0.04) x 10(-14) cm3 molecule(-1) s(-1) for crotonaldehyde, and the proposed Arrhenius expressions are k(T) = (1.72 +/- 0.5) x 10(-13) exp[(-1190 +/- 43)/T] and k(T) = (5.02 +/- 0.7) x 10(-13) exp[(-1076 +/- 47)/T], respectively, in units of cm3 molecule(-1) s(-1). In addition, the products and mechanisms were investigated using an environmental chamber/FTIR absorption system. Formaldehyde, CO, and acryloylperoxy nitrate were identified as the main products for the acrolein reaction with molar yields of 31.6 +/- 2.0, 20.9 +/- 1.9, and 47 +/- 3, respectively. In the crotonaldehyde reaction the main products detected were crotonylperoxy nitrate and CO with yields of 93.6 +/- 4.3 and 8.3 +/- 1.1, respectively. On the basis of the rate constant measured, the activation energy calculated, and the identified products, abstraction of the aldehydic H seems to be the main degradation pathway at room temperature for the reaction of acrolein with NO3. For crotonaldehyde, the mechanism is unclear on the basis of the experimental results. The atmospheric implications of the reactions in question are also discussed.     

Sampling artifacts of acidity and ionic species in PM2.5

Although sampling artifacts of acidity, ammonium, nitrate, and chloride in airborne particulate pollutants can be reduced by the use of denuders to absorb interfering gases, artifacts due to interparticle interactions still remain. In this study, the contribution of individual artifact reactions to particle evaporation and the effects of aerosol composition on the extents of sampling artifacts in PM2.5 were investigated. Samples were collected using a Harvard honeycomb denuder/filter-pack system at an urban site and a rural site in Hong Kong. The results show that the formation of artifacts can be categorized into two regimes: ammonium rich (AR) samples with a molar ratio [NH4+]/ [SO4(2-)] greater than 1.5 and ammonium poor (AP) samples with a molar ratio [NH4+]/[SO4(2-)] less than or equal to 1.5. The urban samples were all AR samples, and they were characterized by high nitrate and low in situ free acid concentrations. In contrast, the rural samples were all AP samples and they were characterized by low nitrate and high in situ free acid concentrations. We have developed a methodology to estimate the contribution of each artifact reaction to the sampling loss of nitrate, chloride, ammonium, and acidity. In the AR samples, the evaporation of HNO3 and HCl and concomitant evaporation of NH3 were the principal reactions in determining the extent of the sampling loss of nitrate and chloride. In the AP samples, the evaporation of HNO3 and HCl alone was the principal reaction instead, especially at high sampling loss. The in situ free acid concentration, a function of aerosol composition and ambient conditions, is a more useful parameter than strong acidity in understanding the sampling loss of acidity, nitrate, and chloride from the collected particles.     

氟虫腈亚砜荧光衍生化、HPLC-FLD检测方法的建立及应用

建立了氟虫腈代谢物-氟虫腈亚砜的柱前荧光衍生化方法,并将其应用于鸡蛋中的残留检测。优化后的柱前荧光衍生化反应主要条件如下:催化缩合剂为EDC/DMAP;反应溶剂为二氯甲烷;氟虫腈亚砜与荧光衍生试剂的用量比为1:8;45 ℃水浴中反应75 min。衍生产物为N-（3-氰基-1-（2, 6-二氯-4-（三氟甲基）苯基)-4-（（三氟甲基）硫代）-1H-吡唑-5-基）-4-（2-（9-乙基-9H-咔唑-3-基）-1H-菲并[9, 10-d]咪唑-1-基）丁酰胺（DX1）,具有很高的荧光强度。衍生化产物DX1的高效液相色谱-荧光检测（HPLC-FLD）的主要条件如下:C₁₈色谱柱;等度洗脱;流动相:乙腈/水（80/20,v/v）;流速:1.0 mL/min;λex=310 nm,λem=404 nm;进样量20 μL;柱温40 ℃。在上述检测条件下,氟虫腈亚砜HPLC-FLD检测方法的检测限为0.033 μg/L,定量限为0.092 μg/L。在此基础上,建立了鸡蛋残留氟虫腈亚砜提取和检测的HPLC-FLD方法,检测限和定量限分别达到了0.052和0.132 μg/kg,精密度、稳定性和重现性在保留时间和峰面积上的RSD分别小于0.04%和2.7%,上机检测可在20 min内完成。该方法具有较好的灵敏度、精确性和可靠性,可应用于鸡蛋中残留氟虫腈亚砜的检测。