Thymol derivatives from schizogyne glaberrima

An investigation of Schizogyne glaberrima afforded in addition to known compounds 3-(acetoxy-methyl)-6-methyl-5-methoxy-benzofuran,10-acctoxy-8,9-epoxy-6-methoxy-thymol isobutyrate, 10-acetoxy-8-hydroxy-9-isobutyryloxy-6-methoxy-thymol,8-hydroxy-9,10-isobutyryloxy-thymol and 8,10-dihydroxy-9-isobutyryloxy-thymol, five new thymol derivatives, 8-ethoxy-9-isobutyryloxy-thymol, 10-acetoxy-8,9-dehydro-6-methoxy-thymol isobutyrate, 6-acetoxy-8,9-dehydro-9-carbomethoxy-10-hydroxy-thymol and 8,9-dihydroxy-10-isobutyryloxy-6-methoxy-thymol.     

Thymol derivatives from Calea nelsonii

Calea nelsonii yielded, besides the two known thymol derivatives 8,9-epoxy-7-isobutyryloxythymol isobutyrate and 10-acetoxy-8,9-epoxythymol isobutyrate, the five new thymol derivatives 10-acetoxy-8,9-epoxy-7- isobutyryloxythymol isobutyrate, 10-acetoxy-8,9-epoxy-7-hydroxythymol isobutyrate, 8-hydroxy-9-acetoxy-10-isobutyryloxythymol 7-acetoxy-8-hydroxy-9,10-diisobutyryloxythymol and 7-isobutyryloxy-8,9-dihydroxythymol, while C. zacatechichi provided the known flavones 5-hydroxy-7,4′-dimethoxy flavone and 5,7-dihydroxy-4′-methoxyflavone and a known epoxysesquiterpene lactone. The structures of the new compounds were established by spectral methods. Some chemotaxonomic aspects are discussed.     

水朝阳旋覆花化学成分的研究

从水朝阳旋覆花(Inula helianthus-aquatica)地上部分分离得到24个化合物,经波谱数据分析分别鉴定为aromaticin(1),8-epi-helenalin(2),bigelovin(3),2,3-dihydroaromaticin(4),carpesiolin(5),ergolide(6),inuchinenolide C(7),6α-acetoxy-isoinuviscolide(8),8-epi-inuviscolide(9),inuchinenolide B(10),tomentosin(11),11α,13-dihydrotomentosin(12),inuchinenolide A(13),4H-tomentosin(14),11β,13-dihydro-4H-tomentosin(15),11-epi-sundiversifolide(16),sundiversifolide(17),8,9,10-三羟基百里香酚(18),10-羟基-8,9-双氧亚异丙基百里香酚(19),8,10-二羟基-9-异丁酰百里香酚(20),8-羟基-9,10-二异丁酰百里香酚(21),8-羟基-9-异丁酰-10-(2-甲基丁酰)百里香酚(22),8,9-环氧-9,10-二异丁酰百里香酚(23)和8,9-环氧-3-异丁酰-10-(2-甲基丁酰)百里香酚(24)。除了化合物1～6外,其他化合物均为首次从该植物中分离得到。     

Perturbation of syntrophic isobutyrate and butyrate degradation with formate and hydrogen

The effect of formate and hydrogen on isomerization and syntrophic degradation of butyrate and isobutyrate was investigated using a defined methanogenic culture, consisting of syntrophic isobutyrate-butyrate degrader strain IB, Methanobacterium formicicum strain T1N, and Methanosarcina mazeii strain T18. Formate and hydrogen were used to perturb syntrophic butyrate and isobutyrate degradation by the culture. The reversible isomerization between isobutyrate and butyrate was inhibited by the addition of either formate or hydrogen, indicating that the isomerization was coupled with syntrophic butyrate degradation for the culture studied. Energetic analysis indicates that the direction of isomerization between isobutyrate and butyrate is controlled by the ratio between the two acids, and the most thermodynamically favorable condition for the degradation of butyrate or isobutyrate in conjunction with the isomerization is at almost equal concentrations of isobutyrate and butyrate. The degradation of isobutyrate and butyrate was completely inhibited in the presence of a high hydrogen partial pressure (>2000 Pa) or a measurable level of formate (10 muM or higher). Significant formate (more than 1 mM) was detected during the perturbation with hydrogen (17 to 40 kPa). Resumption of butyrate and isobutyrate degradation was related to the removal of formate. Energetic analysis supported that formate was another electron carrier, besides hydrogen, during syntrophic isobutyrate-butyrate degradation by this culture. (c) 1996 John Wiley & Sons, Inc.     

Insertion of bacteriorhodopsin into polymerized diacetylenic phosphatidylcholine bilayers

We have developed a method to incorporate the membrane protein bacteriorhodopsin into polymerized bilayers composed of a diacetylenic phosphatidylcholine, 1,2-bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine (DC8,9PC) and a non-polymerizable phospholipid, dinonanoylphosphatidylcholine (DNPC). The extent of DC8,9PC polymerization in the bilayer was significantly improved when 2:1 mole ratio DNPC-DC8,9PC was used. Octyl glucopyranoside-solubilized bacteriorhodopsin was inserted into the polymerized DNPC-DC8,9PC bilayers by overnight incubation at 4 degrees C followed by dialysis to remove the detergent. The protein was inserted into the membranes after photo-polymerization to avoid inactivation of the protein due to the UV irradiation. The insertion of bacteriorhodopsin into the polymerized DNPC-DC8,9PC membranes was confirmed by density gradient centrifugation, UV/visible spectroscopy, and freeze fracture electron microscopy. The polymerized DNPC-DC8,9PC membranes containing bacteriorhodopsin were about 10% protein by weight. These results suggest that mixed lipid systems such as the DNPC-DC8,9PC can be used to improve both the extent of polymerization and the efficiency of membrane protein incorporation in the polymerized bilayer.     

Isobutyrate as a precursor of n-butyrate in the biosynthesis of tylosine and fatty acids

Labelled sodium isobutyrate [(CD3)2-CHCOONa] was added to the culture medium of Streptomyces fradiae and up to 14 atoms of deuterium were found to be incorporated into a molecule of tylosin aglycone (tylactone). This observation is in accordance with the data in the literature. When fatty acids were analyzed, as much as 34% of the isobutyrate incorporated into the cell was formed to be transformed into butyrate that was used for the synthesis of even, straight-chain fatty acids; 57% of the labelled isobutyrate was incorporated into the even isoacids, whereas 9% was degraded to propionate and further used for the synthesis of the odd acids.     

The biosynthesis of valine from isobutyrate by Peptostreptococcus elsdenii and Bacteroides ruminicola

1. Growing cultures of Peptostreptococcus elsdenii and Bacteroides ruminicola incorporate (14)C from [1-(14)C]isobutyrate into the valine of cell protein. With P. elsdenii some of the (14)C is also incorporated into leucine. 2. Crude cell-free extracts of both organisms in the presence of glutamine, carbon dioxide and suitable sources of energy and electrons incorporate (14)C from [1-(14)C]isobutyrate into valine but not into leucine. 3. With extracts of P. elsdenii treated with DEAE-cellulose the reaction is dependent on ATP, CoA, thiamin pyrophosphate, molecular hydrogen and a low-potential electron carrier (ferredoxin, flavodoxin or benzyl viologen). 4. The same extracts incorporate (14)C from NaH(14)CO(3) into valine in the presence of isobutyrate plus ATP, CoA, glutamine and ferredoxin; isobutyryl-CoA or isobutyryl phosphate plus CoA will replace the isobutyrate plus CoA and ATP. With acetyl phosphate in place of isobutyryl phosphate, (14)C is incorporated into alanine. With isovalerate or 2-methylbutyrate in place of isobutyrate, (14)C is incorporated into leucine and isoleucine respectively. 5. When carrier 2-oxoisovalerate is added to the carboxylating system (14)C from [1-(14)C]isobutyrate passes into the oxo acid fraction. 6. It is concluded that these two organisms form valine from isobutyrate by the sequence isobutyrate-->isobutyryl-CoA-->2-oxoisovalerate-->valine and that the reductive carboxylation of isobutyrate is catalysed by a system similar to the pyruvate synthetase of clostridia and photosynthetic bacteria.     

茶毛虫性引诱剂诱杀效果分析

20 0 2年在贵州省都匀茶场研究了茶毛虫性信息素引诱剂大面积诱杀茶毛虫的防治效果 ,并观察了不同浓度以及不同高度设置对诱蛾效果的影响。结果表明 :越冬代试验 2 0d ,诱杀成虫 42 60头 ,第1代试验 44d ,诱杀成虫 1 3 42 3头 ;防治后田间落卵量以及后代幼虫数分别比对照区减少 5 3 3 3 %和60 5 3 % ;诱蛾效果以浓度为 1 5mg 枚的诱芯效果最好 ,诱盆设置高度以 90cm左右为佳。     

Development of aflatoxin B(1)-lysine adduct monoclonal antibody for human exposure studies

Mouse monoclonal antibodies were developed against a synthetic aflatoxin B(1) (AFB)-lysine-cationized bovine serum albumin conjugate. The isotype of one of these antibodies, IIA4B3, has been classified as immunoglobulin G1(lambda). The affinity and specificity of IIA4B3 were further characterized by a competitive radioimmunoassay. The affinities of IIA4B3 for AFB and its associated adducts and metabolites are ranked as follows: AFB-lysine > 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl formamido)-9-hydroxy-AFB > AFB = 8,9-dihydro-8-(N(7)-guanyl)-9-hydroxy-AFB > aflatoxin M(1) > aflatoxin Q(1). IIA4B3 had about a 10-fold higher affinity for binding to AFB-lysine adduct than to AFB when (3)H-AFB-lysine was used as the tracer. The concentration for 50% inhibition for AFB-lysine was 0.610 pmol; that for AFB was 6.85 pmol. IIA4B3 had affinities at least sevenfold and twofold higher than those of 2B11, a previously developed antibody against parent AFB, for the major aflatoxin-DNA adducts 8,9-dihydro-8-(N(7)-guanyl)-9-hydroxy-AFB and 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl formamido)-9-hydroxy-AFB, respectively. An analytical method based on a competitive radioimmunoassay with IIA4B3 and (3)H-AFB-lysine was validated with a limit of detection of 10 fmol of AFB-lysine adduct. The method has been applied to the measurement of AFB-albumin adduct levels in human serum samples collected from the residents of areas at high risk for liver cancer.     

Morphogenesis and tissue cultures of three citrus species

Studies were performed to define tissue culture techniques and culture conditions for morphogenesis, callus culture and plantlet culture of sweet orange (Citrus sinensis (L.) Osb.), citron (C. medica L.) and lime (C. aurantifolia) (Christm. Swing). The optimal concentrations of NAA to induce root formation on stem segments were 10 mg l^-1 for sweet orange and lime, and 3 mg l^-1 for citron. The optimal BA concentration for shoot and bud proliferation was 3 mg l^-1 for sweet orange and citron, and 1 mg l^-1 for lime. Callus initiation was accomplished in a culture medium containing 10 mg l^-1 NAA and 0.25 mg l^-1 BA. Callus was maintained by periodical subculture into the same medium supplemented with 10% (v:v) organge juice. In vitro plantlets of the three species were obtained by rooting of shoots developed from bud cultures, and of citron and lime by development of shoots from root cultures. The plants were successfully established on soil.     

Resistance of Streptomyces cinnamonensis to butyrate and isobutyrate: production and properties of a new anti-isobutyrate (AIB) factor.

Butyrate and isobutyrate (after isomerization to n-butyrate) are specific precursors for the biosynthesis of monensin A in Streptomyces cinnamonensis. High concentrations of both butyrate and isobutyrate (greater than 20 and 10 mM, respectively) were toxic to S. cinnamonensis plated on solid medium. Spontaneous mutants resistant to these substances were isolated. These new strains produced monensins at even higher concentrations of butyrate or isobutyrate, with an increased yield of monensin A. S. cinnamonensis produced an anti-isobutyrate (AIB) factor, which was originally found to be excreted by some isobutyrate-resistant stains growing on solid medium containing isobutyrate. On plates, the AIB factor efficiently counteracted toxic concentrations not only of isobutyrate, but also of acetate, propionate, butyrate, 2-methylbutyrate, valerate and isovalerate against S. cinnamonensis as well as other Streptomyces species. Although the AIB factor enabled normal growth, sporulation and monensin production on plates, it did not have positive effects on submerged cultures of S. cinnamonensis with isobutyrate. The partial purification of the AIB factor was achieved. The role of the AIB factor during spore germination on solid medium containing isobutyrate or its homologues is discussed.     

连作草莓根系分泌物自毒作用的模拟研究

 草莓（Fragaria ananassa）根系分泌物的自毒作用是草莓连作病害发生机理研究的重要内容之一。应用组织培养技术提取草莓根系分泌物,并对其自毒作用进行了测定。结果表明,在含有根系分泌物的生根培养基中定植的草莓组培苗,其生根、根系生长均受到不同程度的抑制,生物量显著下降,而且根系分泌物对草莓幼苗根系生理活性具有抑制作用。主要表现为根系TTC还原活性下降、相对电导率增大、SOD酶活性降低及MDA生成量增多等方面,并导致草莓幼苗生长发育不良、病害加重。说明草莓根系分泌物具有自毒作用,连作条件下田间根系分泌物逐年积累后产生的自毒作用,可能是草莓再植病害发生的重要原因。     

Effects of isobutyrate supplementation in pre- and post-weaned dairy calves diet on growth performance,rumen development,blood metabolites and hormone secretion

Isobutyrate supplements could improve rumen development by increasing ruminal fermentation products, especially butyrate, and then promote the growth performance of calves. The objective of this study was to evaluate the effects of isobutyrate supplementation on growth performance, rumen development, blood metabolites and hormone secretion in pre- and post-weaned dairy calves. In total, 56 Chinese Holstein male calves with 30 days of age and 72.9±1.43 kg of BW, blocked by days of age and BW, were assigned to four groups in a randomized block design. The treatments were as follows: control, low-isobutyrate, moderate-isobutyrate and high-isobutyrate with 0, 0.03, 0.06 and 0.09 g isobutyrate/kg BW per calf per day, respectively. Supplemental isobutyrate was hand-mixed into milk of pre-weaned calves and the concentrate portion of post-weaned calves. The study consisted of 10 days of an adaptation period and a 50-day sampling period. Calves were weaned at 60 days of age. Seven calves were chosen from each treatment at random and slaughtered at 45 and 90 days of age. BW, dry matter (DM) intake and stomach weight were measured, samples of ruminal tissues and blood were determined. For pre- and post-weaned calves, DM intake and average daily gain increased linearly (P<0.05), but feed conversion ratio decreased linearly (P<0.05) with increasing isobutyrate supplementation. Total stomach weight and the ratio of rumen weight to total stomach weight tended to increase (P=0.073) for pre-weaned calves and increased linearly (P=0.021) for post-weaned calves, whereas the ratio of abomasum weight to total stomach weight was not affected for pre-weaned calves and decreased linearly (P<0.05) for post-weaned calves with increasing isobutyrate supplementation. Both length and width of rumen papillae tended to increase linearly for pre-weaned calves, but increased linearly (P<0.05) for post-weaned calves with increasing isobutyrate supplementation. The relative expression of messenger RNA for growth hormone (GH) receptor and 3-hydroxy-3-methylglutaryl-CoA synthase 1 in rumen mucosa increased linearly (P<0.05) for pre- and post-weaned calves with increasing isobutyrate supplementation. Blood concentrations of glucose, acetoacetate, β-hydroxybutyrate, GH and IGF-1 increased linearly (P<0.05) for pre- and post-weaned calves, whereas blood concentration of insulin decreased linearly with increasing isobutyrate supplementation. The present results indicated that isobutyrate promoted growth of calves by improving rumen development and its ketogenesis in a dose-dependent manner.     

Cytotoxic alpha-pyrones from Xylaria hypoxylon

Two new alpha-pyrone derivatives, xylarone (1) and 8,9-dehydroxylarone (2) possessing cytotoxic activities, were isolated from the culture fluid of submerged cultures of the ascomycete Xylaria hypoxylon, strain A27-94. Their structures were elucidated by spectroscopic methods.     

Isolation and Identification of Ubiquinone 10 from Cultured Cells of Tobacco

Callus tissues were induced from stem and root segments of Rauwolfia serpentina. Growth and alkaloid production of the callus tissues were examined under various culture conditions. The growth was strikingly promoted in the presence of 2,4-D (0.5~1 ppm), kinetin (0.2~0.5 ppm) and yeast extract (0.1~0.2%). At favourable conditions, the growth value in 4 weeks’ culture was ca. 40 (F.W.), and ca. 25 (D.W.) for stem callus tissues, and ca. 15 (F.W.), and ca. 8 (D.W.) for root callus tissues. Stem and root callus tissues produced ajmaline and some other unidentified Rauwolfia alkaloids. The ajmaline content in root callus tissues was 10~20mg % and in stem callus tissues was 1~10mg %. The ajmaline production was strikingly reduced when 2,4-D concentration increased, or kinetin was omitted in the culture medium. Phytosterols including stigmasterol, β-sitosterol or cholesterol were also produced.     

Beta-cyclolavandulyl and beta-isocyclolavandulyl esters from Peucedanum paniculatum L., an endemic species to Corsica

Eight cyclolavandulyl esters (beta-cyclolavandulyl and beta-isocyclolavandulyl acetate, propionate, isobutyrate, isovalerate) were identified in the leaf and root oils of Peucedanum paniculatum L., an endemic species to Corsica, by comparison of their spectroscopic data with those of synthetic material. Their structures were elucidated by spectroscopic methods. The antimicrobial activity of essential oils of leaves and roots was evaluated against eleven microorganisms.     

Anaerobic Degradation of Normal- and Branched-Chain Fatty Acids with Four or More Carbons to Methane by a Syntrophic Methanogenic Triculture

Syntrophic degradation of normal- and branched-chain fatty acids with 4 to 9 carbons was investigated with a mesophilic syntrophic isobutyrate-butyrate-degrading triculture consisting of the non-spore-forming, syntrophic, fatty acid-degrading, gram-positive rod-shaped strain IB, Methanobacterium formicicum T1N, and Methanosarcina mazei T18. This triculture converted butyrate and isobutyrate to methane and converted valerate and 2-methylbutyrate to propionate and methane. This triculture also degraded caproate, 4-methylvalerate, heptanoate, 2-methylhexanoate, caprylate, and pelargoate. During the syntrophic conversion of isobutyrate and butyrate, a reversible isomerization between butyrate and isobutyrate occurred; isobutyrate and butyrate were isomerized to the other isomeric form to reach nearly equal concentrations and then their concentrations decreased at the same rates. Butyrate was an intermediate of syntrophic isobutyrate degradation. When butyrate was degraded in the presence of propionate, 2-methylbutyrate was synthesized from propionate and isobutyrate formed from butyrate. During the syntrophic degradation of valerate, isobutyrate, butyrate, and 2-methylbutyrate were formed and then degraded. During syntrophic degradation of 2-methylbutyrate, isobutyrate and butyrate were formed and then degraded.     

Production and release of pigments by culture of transformed hairy root of red beet

Adventitious roots were induced from red beet (Beta vulgaris L. cv. Detroit dark red) by infecting the plant with a soil bacterium, Agrobacterium rhizogenes. Based on analysis of opines which are uniquely produced in transformed hairy roots, the established clone was proved to be a transformed hairy root. In a shake culture of the beet hairy root clone with a liquid medium, it was found that significant amounts of pigments, mainly betanin and vulgaxanthin-I, were released into the medium by the cessation of culture shaking (temporary limitation of oxygen supply). The hairy root cells were capable of propagation even after the cells were subjected to shaking cessation. Repeated-batch culture of the beet hairy root was performed with the cell growth phases for 9 or 10 d and with pigment leakage phases during shaking cessation for 2 d, and more than 20% of the total intracellular pigments were recovered from the culture broth at a culture time of 35 d. The released pigments were confirmed to be substantially identical to those extracted from the hairy root and original plant cells of red beet.     

Effects of isobutyrate on rumen fermentation, lactation performance and plasma characteristics in dairy cows

The objective of this study was to evaluate effects of isobutyrate supplementation on rumen fermentation, lactation performance and plasma characteristics of dairy cows. Twenty multiparous second filial generation (F2) cows of a cross between Chinese Jinnan Yellow and Holstein cows at 148 ± 4.5 days in milk and 22.3 ± 0.81 kg milk production were used in a replicated 4 × 4 Latin square experiment. The treatments were: control (without isobutyrate), low (LIB), medium (MIB) and high (HIB) isobutyrate supplementation of 20, 40 and 60 g per cow per day, respectively. Experimental periods were 30 days with 15 d of adaptation and 15 d of data collection. Dry matter (DM) intake was not affected by increasing isobutyrate supplementation, but milk yields were highest for the 40 g/d isobutyrate supplementation level, where proportion of milk fat, true protein and lactose were minimized. Ruminal pH (6.38–6.24) and ammonia N (13.8–11.1 mg/100 ml) were linearly (P<0.01) decreased, whereas total VFA concentration (124–131 mM) increased at a decreasing rate with increasing isobutyrate supplementation. The ratio of acetate to propionate increased linearly (P<0.01) from 2.77 to 4.43 as isobutyrate supplementation increased due to the increase in acetate production and decrease in propionate production. Digestibilities of OM in the total tract increased linearly (P<0.01) as isobutyrate supplementation increased, digestibilities of DM and EE were highest for the 40 g/d isobutyrate supplementation level, digestibilities of CP, aNDF and ADF increased at a decreasing rate with increasing isobutyrate supplementation. Plasma concentrations of glucose and growth hormone linearly (P<0.03) increased, whereas concentrations of non-esterified fatty acids linearly (P<0.01) decreased. Results indicate that supplementation of this diet with isobutyrate changed the rumen fermentation pattern towards acetate production, improved digestion and modified plasma concentrations of glucose and growth hormone. This suggests that isobutyrate stimulated digestive microorganisms or enzymes in a dose-dependent manner with the optimum isobutyrate dose at about 40 g per cow per day in terms of improved digestion.     

Interindividual variation in the levels of certain urinary polycyclic aromatic hydrocarbon metabolites following medicinal exposure to coal tar ointment

Determination of human exposure to polycyclic aromatic hydrocarbons PAHs is challenging because they are so broadly distributed in the environment and often difficult to quantitate using questionnaire methods. To enhance the ability to non invasively evaluate markers of both internal dose and biologically effective dose we have developed methods for the identification and quantitation of 1 hydroxypyrene-glucuronide and r 7, t 8, t 9, c 10 tetrahydroxy 7,8,9,10 tetrahydrobenzo a pyrene BP 7,10 8,9 tetrol in human urine. In the current study we applied these assays to urine samples collected from 43 hospitalized psoriasis patients treated with coal tar medication and 39 non treated volunteer controls. BP 7,10 8,9 tetrol was detected in 20 of 43 47 patients, ranging from 1 not detected to 124 fmol mumol-1 creatinine. In contrast, BP 7,10 8,9 tetrol was detected in only 4 of 39 10 controls, range 1 to 20.6 fmol mumol-1 creatinine p = 0.0006, Wilcoxon rank sum test . A second, more polar PAH metabolite, identified as 1 hydroxypyrene-glucuronide, was present in all urine samples. Mean 1 hydroxypyreneglucuronide levels were 40.96 72.62 pmol mumol-1 creatinine in patients and 0.38 0.32 pmol mumol-1 creatinine in control subjects p 0.0001 . The ratio of urinary levels of BP 7,10 8,9 tetrol to 1 hydroxypyrene-glucuronide was examined in the coal tar treated patients. This ratio was found to vary by approximately 6000 fold. This parameter cannot be explained by measurement error because the coefficients of variation for these assays are only 12 and 10 respectively, nor can it be explained by use of different coal tar products. These results provide further evidence that substantial interindividual variation in activation of benzo a pyrene and other PAHs exists, which may have implications for disease risk.