动物气味的项空取样技术及其在水貂肛腺成分分析中的应用

我们设计了一种用于动物气味的顶空（heqadspace）取样装置,并结合溶剂解吸附和气质联用技术,通过对水貂（Mustela vision）肛腺分泌物的挥发性成分的分析验证这种装置的可行性,出现5个气谱峰,对应的质谱显示其分子量和分子式依次为峰1：102（C5H10S）、峰2：104（C5H12S）、峰3：102（C5H10S）、峰4：136（C5H12S2）和峰5：134（C5H10S2）。峰1、峰3和峰5分别为以前研究所鉴定出的3种主要成分：2,2－二甲基硫代环本烷、2－乙基硫代环丁烷和3,3－二甲基－1,2－二硫代环戊烷,2,2－二甲基硫代环丁烷为优势成分,组成无性别间差异。这些结果与以前研究一致。说明了这种顶空取样装置的可靠性,峰2－峰4两种成分以前在水貂肛腺中未曾发现,初步分析可能分别为3－甲基－1－丙基硫醇和1,5－戊二硫醇,尽管这两个成分有待进一步分析确定,但可以肯定分子量为104和136的成分不仅在水貂肛腺分泌物中没有发现过,而且在已经研究过的鼬属动物和食肉类的肛腺中都未发现珲,能检测出更多的成分,说明这种方法的可靠性很高。     

黄鼬肛腺分泌物的挥发性成分

利用顶空取样、溶剂解吸附和气质联用技术分析了黄鼬（Mustela sibirica)肛腺分泌物的挥发性成分。鉴定出的六种化合物均为含硫的环状有机物：（1）2,2－二甲基硫代环丁烷;（2）顺或反2,4－二甲基硫代环丁烷;（3）反－2,3－二甲基硫代环丁烷;（4）2－乙基硫代环丁烷;（5）2－丙基硫代环丁烷;（6）3,3－二甲基－1,2－二硫代环戊烷。尽管黄鼬肛腺成分的组成和鼬鼠其它种存在很大的相似性,但是成分组成的种间差异很明显。另外,2－乙基硫代环丁烷仅存在于雌性黄鼬中。很多研究已经证明对鼠类有驱赶作用的2,2－二甲基硫代环丁烷和2－丙基硫代环丁烷在黄鼬肛腺分泌物同时存在,说明黄鼬肛腺分泌物对鼠类可能有很强的驱避作用。     

乌骨鸡黑素的一些基本结构特征的初步研究

应用元素分析、电子能谱(XPS)和红外光谱(IR)分析技术对乌骨鸡体内黑素结构特征进行了研究。元素分析结果得到黑素分子中C、H、N、O克原子比率的均值为10:12:1:3.该比值与动物性吲哚黑素的相应元素比例接近。XPS波谱显示出黑素中含有两种价态的硫(S~Ⅵ、S~Ⅰ),其中以低价态占优势,S2p电子结合能比人发黑素要大些。氮原子只有一种价态。IR光谱中有五组明显吸收峰,其中以主要表征吲哚环的1619—1632CM~(-1)处的吸引峰最强。以上结果初步表明出乌骨鸡黑素是以吲哚环为主体的异聚物。     

杠柳根皮挥发油化学成分及对麦二叉蚜的毒杀活性初探

采用GC/M S联用技术,对杠柳根皮中挥发油的化学成分进行了分析,共分离出15种化合物,对其中10种进行了鉴定,已鉴定成分占挥发油总成分的94.91%,分别为4-甲氧基水杨醛、乙酸丁酯、2-甲基-1,3-二氧环戊基乙酸乙酯、乙羟硫代羧酸-8-二乙氧基磷酰正辛酯、1,1,3,3-四丁氧基-2-丙酮、4-甲基-2-戊酮、甲酸丁酯、1-(1-乙氧基乙氧基)丁烷、2-正丁氧基四氢吡喃及丁醚。以麦二叉蚜为试虫进行挥发油杀虫活性测定。结果表明,杠柳根皮挥发油对试虫具有较强的触杀活性。     

假蜜环菌的研究II．假蜜环菌素的分离及化学结构的测定

从假蜜环菌培养物的乙醇提取物中分离得四种成分,其中之一为新的香豆素,定名为假蜜环菌甲素(Armillarisin A),为治疗胆囊炎的一种活性成分。分子式C12H10O5,熔点245—246℃,用紫外、红外光谱,质谱,核磁共振确定假蜜环菌甲素为3—乙酰基一5羟甲基一7一羟基香豆素。另一成分定名为假蜜环菌乙素,熔点162一163．5℃,分子式C9H10N2O3,用同样的方法初步测定了它的结构。     

铁皮石斛内生真菌次生代谢产物研究

为了解铁皮石斛(Dendrobium officinale)内生真菌Phyllosticta aristolochiicola的次生代谢产物,从该真菌中分离得到15个化合物,经波谱分析分别鉴定为N-methyl-2-pyrolidinone (1)、环-(甘氨酸-L-脯氨酸)(2)、环-(D-丙氨酸-L-脯氨酸)(3)、环-(L-缬氨酸-L-脯氨酸)(4)、环-(L-亮氨酸-L-脯氨酸)(5)、cyclo-(L-Leu-D-4-hydroxyprolinyl)(6)、环-(L-苯丙氨酸-L-脯氨酸)(7)、环-(L-苯丙氨酸-L-4-羟基脯氨酸)(8)、环-(L-酪氨酸-L-脯氨酸)(9)、环-(L-苯丙氨酸-L-亮氨酸)(10)、啤酒甾醇(11)、对羟基苯乙醇(12)、对羟基苯乙酸(13)、(2S,3R)-1-(4-羟基苯基)丁烷-2,3-二醇(14)和(2R,3S)-1-苯基丁烷-2,3-二醇(15)。采用MTS法检测抗肿瘤活性表明,化合物2、10和14对HL-60、A-549、SMMC-7721、MCF-7和SW-480细胞株具有一定的抑制活性。     

MiR-21协同BMP9促进间充质干细胞C3H10T1/2成骨分化

目的:探讨miR-21与BMP9之间的关系,明确miR-21在BMP9诱导间充质干细胞成骨分化中的作用。方法:(1)Ad-BMP9感染C3H10T1/2细胞,Real-time-PCR检测miR-21表达。RT-PCR检测ALP的表达。(2)MiR-21转染C3H10T1/2细胞,Real-time-PCR检测miR-21和BMP9表达。(3)MiR-21和BMP9-CM处理C3H10 T1/2细胞,ALP活性和染色实验检测C3H10 T1/2细胞早期成骨能力。茜素红S染色实验检测钙盐沉积情况。(4)MiR-21和BMP9-CM处理C3H10 T1/2细胞,Real-time-PCR检测成骨分化相关因子ALP,OCN的表达。(5)MiR-21和BMP9-CM处理C3H10T1/2细胞,Western blot检测p-Smad1/5蛋白水平的表达。结果:(1)BMP9暂时降低miR-21的表达。MiR-21也可以暂时降低BMP9的表达。(2)MiR-21可以协同BMP9增强ALP和钙盐沉积。(3)MiR-21协同BMP9增加了p-Smad1/5蛋白水平的表达。结论:MiR-21与BMP9存在相互关系,两者可以互相调节表达。MiR-21可以协同BMP9促进间充质干细胞C3H10T1/2细胞成骨分化,这一过程与增强BMP9/Smad信号的激活程度有关。     

含硫香料——硫代芳樟醇及其衍生物的合成研究

本文对香叶醇转化为硫代芳樟醇(4)及其衍生物的合成方法进行了研究。香叶醇与N,N-二甲基琉代氨基甲酰氯反应生成N,N—二甲基琉代氨基甲酸-O-香叶基酯(5),(5)通过[3,3]-σ迁移反应转变成N,N-二甲基硫代氨基甲酸-S-芳樟基酯(6),(6)进一步还原得到硫代芳樟醇(4)。(4)转变成衍生物硫代芳樟醇乙酸酯(7a)及芳樟基甲基疏醚(7b)。(4)及(7b)在高度稀释时具有愉快的热带水果香味。     

利用~1H-NMR模拟谱研究三核苷酸A3′P(CH_3)5′A3′P(CH_3)5′A的构象性质

根据Altona等人的方法.利用~1H—NMR模拟谱分析了A3′P(CH_3)5A3′P(CH_3)5′A的三种非对映异构体:a、b和C的构象状态.发现:在室温下三个核糖环都是S型构象占优势(X_N≤0.44),而且随温度升高S型构象成分增多;两个二核苷酸片段-PAPA和APAP-的磷酸骨架扭角分别与A3′P(CH_3)5′A两种异构体a或b数值接近.差值约5°左右;二核苷酸片段中核糖环的重叠程度与手性磷原子的构型有关、R构型比S构型的核糖环重叠程度小;从而推测,A3′P(CH_3)5′A3′P(CH_3)5′A各种非对映异构体的稳定性为RR>RS.SR>SS,与化学合成中所见相符合.     

高脂血症大鼠下颌下腺内AQP1和AQP5表达及意义

目的 观察高脂血症大鼠下颌下腺内AQP1和AQP5表达的变化.方法雄性 S D大鼠 20只,随机分为 2组,对照组(C组)给予全价颗粒饲料喂养;高脂饮食组(H组)给予高脂饮食 (饲料成分为胆固醇 2%、猪油10%、基础饲料 88% )连续喂养2个月,各组动物均不限制饮水.2个月成模后,取血检测血脂;取大鼠下颌下腺组织,进行免疫组织化学染色(SP法) 和计算机图像分析.结果 ①血脂检测结果:C组TG与H组TG比较有显著性差异(P<0.05);C组TC和H组TC比较有显著性差异(P<0.05).②免疫组化结果:C组大鼠下颌下腺AQP1平均光密度值与 H组AQP1平均光密度值比较有差异性(P<0.05);C组大鼠下颌下腺AQP5平均光密度值与 H组AQP5平均光密度值比较有差异性(P<0.05).结论 高脂血症大鼠下颌下腺导管上皮细胞内AQP1和AQP5的表达减少,为探讨高脂血症导致下颌下腺分泌功能降低的病理机制提供了形态学依据.     

Detection of flavor compounds in longissimus muscle from four hybrid pig breeds of Sus scrofa,Bamei pig,and Large White

To detect the flavor quality and flavor compounds in raw longissimus muscle from four typical pig breeds: Sus scrofa?×?Bamei pig named F1 (group A), F1?×?F1 (group B), F1?×?Bamei pig (group C), and F1?×?Large White (group D). The chemical compositions of longissimus muscles from four breeds were examined using headspace solid-phase microextraction/gas chromatography mass spectrometry method. Distinct differences for the same flavor compounds of longissimus muscles between different breeds were analyzed. Totally 64 flavor compounds shared in four groups, and 10 flavor compounds with significant difference among four groups (p?<?0.05), including allyl butyrate, (Z)-2-penten-1-ol, 2,2-dimethyl-3-methyl oxirane, 2-pentylfuran, dodecane, 2,4-decadienal, vinylsilane, 3-methyl-1-butanol, (1-methyldecyl)-benzene, and dipropyl phthalate. Totally, 23–41 flavor compounds did not commonly exist in four groups, such as only as dibutyl isophthalate in group A; 6,10-dimethyl-5-9-undecadien-2 one, bis (2-trimethylsilyl) ethyl ester-malonic acid, heptadecane, 2,4,6-trimethyl pyridine, and diisooctyl adipate in group C alone; and 1,3-dimethylcyclopentanol, 2-octanone, and trimethylsilane in group D alone. While, no specific flavor compounds were identified in group B. All these flavor compounds covered 12 types of hydrocarbons, alcohols, aldehydes, hydroxybenzenes, acids, ketones, esters, sulfides, furans, alkenes, and pyrrole. Besides, we analyzed 14 flavor compounds with different flavors combining with previous studies. The flavor compounds in longissimus muscles might be closely related to the breeds, and the hybrid of S. scrofa?×?Bamei pig had the most flavor compounds in raw longissimus muscle.     

Isoprenylated xanthones and flavonoids from Cudrania tricuspidata

Further phytochemical investigation on the roots of Cudrania tricuspidata afforded a new isoprenylated xanthone, cudratricusxanthone I (1), two new isoprenylated flavanones, cudraflavanones C and D (2 and 3, resp.), and seven known compounds, 1,7-dihydroxy-3,6-dimethoxyxanthone (4), macluraxanthone C (5), cudraxanthones E, K, and L (6, 7, and 8, resp.), cudraflavanone A (9), and cudraflavone C (10). Their structures were identified by spectroscopic methods. Cudratricusxanthone H (12), macluraxanthone B (13), two xanthones previously isolated from this plant, and 5, showed significant inhibitory effects on four kinds of human digestive apparatus tumor cell lines (HCT-116, SMMC-7721, SGC-7901, and BGC-823) with IC50 values of 2.70-12.66 microM.     

Putative chemosignals of the ferret (Mustela furo) associated with individual and gender recognition

Quantitative stir bar sorptive extraction methods, both in the aqueous and headspace modes, followed by thermal desorption gas chromatography-mass spectrometry were used to investigate individual variations in the volatile components of male and female ferret (Mustela furo) urine. The urinary profiles were further compared with volatile profiles of anal gland secretions of breeding male and female ferrets. Thirty volatile compounds were quantified in male and female urine. Among them, 2-methylquinoline was unique to male urine. Four ketones (4-heptanone, 2-heptanone, o-aminoacetophenone, and a dimethoxyacetophenone) and several nitrogen compounds (e.g., 2,5-dimethylpyrazine, quinoline, 4-methylquinazoline) and low levels of three unidentified nonsulfur compounds were significantly more abundant in males than in females. Quantitative comparison of 30 volatile urinary compounds showed several statistically significant differences between the sexes and individuals of the same sex. These findings suggest that ferrets may use urine marking for sex and individual recognitions. Ten of the 26 compounds identified in anal gland secretions from females and males were also found in urine. However, most of the major compounds (thietanes, dithiolanes, and indole) in anal glands were not present in urine. This suggests that urine may convey specific signals that differ from those of anal glands. Additionally, 10 volatiles (two aldehydes, five ketones, benzothiazole, 2-methylquinoline, and 4-methylquinazoline), not previously identified, were found in ferret anal gland secretions. Among the new compounds, o-aminoacetophenone was found only in males, while only traces of this compound were found in females. Similar results were previously obtained in anal glands of three other Mustela species. These findings provide new information about the constituents of urine and volatile components of anal gland secretions in ferrets.     

Possible coding for recognition of sexes,individuals and species in anal gland volatiles of Mustela eversmanni and M. sibirica

With a combination of solvent extraction and gas chromatography-mass spectrometry, we found eight new compounds in the two sympatric Mustela species, M. eversmanni and M. sibirica. These compounds had not been detected by headspace sampling with solvent desorption. Two of the newly detected compounds are nitrogen-containing compounds, indole and o-aminoacetophenone and the remaining are sulfur-containing volatiles. By comparing same and opposite sexes between the two Mustela species, we found that qualitative differences in the anal gland secretion are most likely to be used to code for information about species, corresponding to the idea of digital coding. In the Siberian weasel (M. sibirica), both presence or absence of sex-specific compounds (Z-2-ethyl-3-methylthietane only in females) and relative abundance of some compounds between males and females could be used to code for information about sex, corresponding to the idea of digital and analog coding, respectively. In the steppe polecat (M. eversmanni), only quantitative differences provided the possibility for inter-sexual communication. Thus coding for information about sex appeared to be digital. Coding for individual information could also be either digital or analog or both through the presence or absence of certain compounds and/or the difference in the relative abundances of certain compounds among individuals. Comparing with other Mustela spp., we failed to find a congruence between the chemical composition of anal gland secretions and the phylogenetic relationship among the species in this genus.     

Odour-mediated nectar foraging in the silver Y moth, Autographa gamma (Lepidoptera: Noctuidae): behavioural and electrophysiological responses to floral volatiles

Naive male and female silver Y moths, Autographa gamma (Lepidoptera: Noctuidae), were attracted in a flight tunnel assay to potted creeping thistle, Cirsium arvense (Asteraceae), butterfly-orchid, Platanthera bifolia (Orchidaceae), soapwort, Saponaria officinalis (Caryophyllaceae), greater knapweed, Centaurea scabiosa (Asteraceae), red clover, Trifolium pratense (Fabaceae), and catnip, Nepeta faasseni (Labiatae), plants with flowers. The most attractive plants were C. arvense , P. bifolia and S. officinalis that elicited 87, 78 and 65% source contacts, respectively. C. scabiosa was less attractive eliciting 43% response. T. pratense and N. faasseni showed the least attraction eliciting 28 and 26% source contacts, respectively. A cotton plant used as control, was not attractive. Floral volatiles from the investigated plant species were collected using headspace sampling technique. Samples were analysed using gas chromatography coupled with electroantennographic detection, and electrophysiologically active compounds were identified by coupled gas chromatography/mass spectrometry. Consistent electrophysiological responses were elicited by twelve compounds from headspace of C. arvense , thirteen compounds from P. bifolia , eleven compounds from S. officinalis , nine from C. scabiosa , ten from T. pratense and two from N. faasseni . Most of the active compounds were specific for one or two species, while benzyl benzoate was present in four and benzaldehyde and benzyl alcohol in three species. Floral scents of C. arvense , P. bifolia and S. officinalis , the most attractive flowers, were dominated by aromatic compounds that were not abundant in the scent of other flowers. To conclude, the results demonstrate the absence of a common denominator of odours present in flowers of different plants visited by A. gamma .     

Crystal structures of two engineered thiol trypsins

We have determined the three-dimensional structures of engineered rat trypsins which mimic the active sites of two classes of cysteine proteases. The catalytic serine was replaced with cysteine (S195C) to test the ability of sulfur to function as a nucleophile in a serine protease environment. This variant mimics the cysteine trypsin class of thiol proteases. An additional mutation of the active site aspartate to an asparagine (D102N) created the catalytic triad of the papain-type cysteine proteases. Rat trypsins S195C and D102N,S195C were solved to 2.5 and 2.0 A, respectively. The refined structures were analyzed to determine the structural basis for the 10(6)-fold loss of activity of trypsin S195C and the 10(8)-fold loss of activity of trypsin D102N,S195C, relative to rat trypsin. The active site thiols were found in a reduced state in contrast to the oxidized thiols found in previous thiol protease structures. These are the first reported structures of serine proteases with the catalytic centers of sulfhydryl proteases. Structure analysis revealed only subtle global changes in enzyme conformation. The substrate binding pocket is unaltered, and active site amino acid 102 forms hydrogen bonds to H57 and S214 as well as to the backbone amides of A56 and H57. In trypsin S195C, D102 is a hydrogen-bond acceptor for H57 which allows the other imidazole nitrogen to function as a base during catalysis. In trypsin D102N,S195C, the asparagine at position 102 is a hydrogen-bond donor to H57 which places a proton on the imidazole nitrogen proximal to the nucleophile. This tautomer of H57 is unable to act as a base in catalysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

New chemical constituents from the endophyte Streptomyces species LR4612 cultivated on Maytenus hookeri

From solid cultures of the biologically important endophyte Streptomyces species LR4612, cultivated on Maytenus hookeri, four new and two known compounds were isolated. The new compounds were identified as (2S*,3S*)-5-amino-3-hydroxy-5-oxopentan-2-yl 3-(formylamino)-2-hydroxybenzoate (1), N-[(3R*,4R*)-3-amino-3,4-dihydro-4-methyl-2,6-dioxo-2H,6H-1,5-benzodioxocin-10-yl]formamide (2), (5beta,6alpha)-6,11-dihydroxyeudesmane (3), and 5-(6,7-dihydroxy-6-methyloctyl)furan-2(5H)-one (4); the known compounds were elucidated as sorbicillin (5) and N-acetyltyramine (6). The structures were established by HR-ESI-MS and in-depth NMR analyses.     

A marine Mesorhizobium sp. produces structurally novel long-chain N-acyl-L-homoserine lactones

Our study focused on a Mesorhizobium sp. that is phylogenetically affiliated by 16S rRNA gene sequence to other marine and saline bacteria of this genus. Liquid chromatography-mass spectrometry investigations of the extract obtained from solid-phase extraction of cultures of this bacterium indicated the presence of several N-acyl homoserine lactones (AHLs), with chain lengths of C(10) to C(16). Chromatographic separation of the active bacterial extract yielded extraordinarily large amounts of two unprecedented acylated homoserine lactones, 5-cis-3-oxo-C(12)-homoserine lactone (5-cis-3-oxo-C(12)-HSL) (compound 1) and 5-cis-C(12)-HSL (compound 2). Quorum-sensing activity of compounds 1 and 2 was shown in two different biosensor systems [Escherichia coli MT102(pSB403) and Pseudomonas putida F117(pKR-C12)]. Furthermore, it was shown that both compounds can restore protease and pyoverdin production of an AHL-deficient Pseudomonas aeruginosa PAO1 lasI rhlI double mutant, suggesting that these signal molecules maybe used for intergenus signaling. In conclusion, these data indicate that the quorum-sensing activity of compounds 1 and 2 is modulated by the chain length and functional groups of the acyl moiety. Additionally, compound 1 showed antibacterial and cytotoxic activities.     

鞭打绣球中的一个新单萜苷

从鞭打绣球(Hemiphragma heterophyllum Wall.)全草中分离到1个新单萜苷和7个已知化合物.通过波谱数据分析,新单萜苷的结构鉴定为(4S)-α-萜烯醇-8-O-β-D-比喃木糖-(1→6)-β-D-比喃葡萄糖苷,已知化合物分别鉴定为globularin(2)、(2S 3S,4R,9E)-1,3,4-trihydroxy-2-[(2'R)-hydroxy-tetracosanoylamino]-9-octadecene(3)、β-香树素(4)、齐墩果酸(5)、肉桂酸(6)、β-谷甾醇(7)和胡萝卜甙(8).除化合物2外,其余化合物均为首次从鞭打绣球中分离得到.