首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The geographical distribution and analysis of the essential oils of species from three sections of Hypericum L. (Guttiferae/Clusiaceae/Hypericaceae) from Portugal are presented. Hypericum perfoliatum (section Drosocarpium) grows wild in the centre and south of Portugal; Hypericum humifusum and Hypericum linarifolium are both from section Oligostema, the former occurring throughout the country, while the second is distributed mainly in the north and centre; Hypericum pulchrum (section Taeniocarpium) is confined to the littoral north of Portugal. The essential oils were obtained by distillation–extraction, hydrodistillation and distillation in a modified Marcusson apparatus from the dried aerial parts of the different populations and were analysed by GC and GC–MS. Monoterpene hydrocarbons constituted the main fraction in all oils (43–69%, 53–85%, 28–45% and 48–65% for H. perfoliatum, H. humifusum, H. linarifolium and H. pulchrum, respectively). Sesquiterpene hydrocarbons (2–13%, 6–18%, 21–27% and 16–18%, respectively) and a third fraction of non-terpenic compounds (20–29%, 3–16%, 2–14% and 5–11%, respectively) from the four species attained relatively high amounts in all oils. Within each species, no major differences were detected in the essential oil composition, despite the fact that different locations, phenological phases and extraction methodologies were used. Notwithstanding the dominance of α-pinene in all four species' oils, cluster and principal components analysis on the identified components showed that the range of α-pinene, β-pinene and n-nonane supported a separation of the four species. The essential oil composition of the four species showed some qualitative resemblances, which correlate well with the taxonomical classification based on morphological characters.  相似文献   

2.
RIG-I (retinoic acid-inducible gene I) is an essential cytosolic pathogen recognition receptor that binds to a variety of viral RNA or DNA to induce type I interferons. In the present study, insert–deletion polymorphisms in promoter and introns of CiRIG-I (Ctenopharyngodon idella RIG-I) were explored, their associations with resistance/susceptibility to grass carp reovirus (GCRV) were analyzed. To this end, genomic sequence of CiRIG-I gene was obtained, and twenty pairs of primers were prepared for the detection of insert–deletion polymorphisms. Five insert–deletion mutations were found, a 2-bp mutation and an 8-bp mutation existed in the promoter and other three sizes in 74 bp, 146 bp and 53 bp were sited in the intron 8. After a challenge experiment, only the genotype and allele of − 740 insert–deletion mutation in the promoter and allele of 6804 insert–deletion mutation were significantly associated with resistance/susceptibility to GCRV among the five mutations (P < 0.05). To further identify this correlation, another independent challenge test was carried out. The result revealed that the cumulative mortality in ins/ins genotype individuals (43.75%) at − 740 insert–deletion mutation was significantly lower than that in ins/del (72.09%) and del/del (74.19%) genotypes (P < 0.05). Linkage disequilibrium and haplotype analysis showed 6610 insert–deletion mutation and 6804 insert–deletion mutation were linkage disequilibrium. The haplotype ins–ins (6610ins–6804ins) was significantly susceptible to GCRV, and ins–del (6610ins–6804del) was significantly resistant to GCRV (P < 0.05). Those could be potential gene markers for the future molecular selection of strains that are resistant to GCRV.  相似文献   

3.
In this study, we report a novel cellulase [β-1,4-endoglucanase (EGase), EC 3.2.1.4] cDNA (Bh-EGase II) belonging to the glycoside hydrolase family (GHF) 45 from the beetle Batocera horsfieldi. The Bh-EGase II gene spans 720 bp and consists of a single exon coding for 239 amino acid residues. Bh-EGase II showed 93.72% protein sequence identity to Ag-EGase II from the beetle Apriona germari. The GHF 45 catalytic site is conserved in Bh-EGase II. Bh-EGase II has three putative N-glycosylation sites at 56–58 (N–K–S), 99–101 (N–S–T), and 237–239 (N–Y–S), respectively. The cDNA encoding Bh-EGase II was expressed in baculovirus-infected insect BmN cells and Bombyx mori larvae. Recombinant Bh-EGase II from BmN cells and larval hemolymph had an enzymatic activity of approximately 928 U/mg. The enzymatic catalysis of recombinant Bh-EGase II showed the highest activity at 50 °C and pH 6.0.  相似文献   

4.
The family Trigonalyidae is considered to be one of the most basal lineages in the suborder Apocrita of Hymenoptera. Here, we determine the first complete mitochondrial genome of the Trigonalyidae, from the species Taeniogonalos taihorina (Bischoff, 1914). This mitochondrial genome is 15,927 bp long, with a high A + T-content of 84.60%. It contains all of the 37 typical animal mitochondrial genes and an A + T-rich region. The orders and directions of all genes are different from those of previously reported hymenopteran mitochondrial genomes. Eight tRNA genes, three protein-coding genes and the A + T-rich region were rearranged, with the dominant gene rearrangement events being translocation and local inversion. The arrangements of three tRNA clusters, trnYtrnMtrnItrnQ, trnWtrnL2trnC, and trnHtrnAtrnRtrnNtrnStrnEtrnF, and the position of the cox1 gene, are novel to the Hymenoptera, even the insects. Six long intergenic spacers are present in the genome. The secondary structures of the RNA genes are normal, except for trnS2, in which the D-stem pairing is absent.  相似文献   

5.
6.
The phylogeny and taxonomic position of slow-growing Genista tinctoria rhizobia from Poland, Ukraine and England were estimated by comparative 16S rDNA, atpD, and dnaK sequence analyses, PCR-RFLP of 16S rDNA, DNA G + C content, and DNA–DNA hybridization. Each core gene studied placed the G. tinctoria rhizobia in the genus Bradyrhizobium cluster with unequivocal bootstrap support. G. tinctoria symbionts and bradyrhizobial strains shared 96–99% similarity in 16S rDNA sequences. Their similarity for atpD and dnaK sequences was 93–99% and 89–99%, respectively. These data clearly showed that G. tinctoria rhizobia belonged to the genus Bradyrhizobium. 16S rDNA sequence analysis was in good agreement with the results of the PCR-RFLP of the 16S rRNA gene. Although the tested strains formed separate lineages to the reference bradyrhizobia their RFLP 16S rDNA patterns were quite similar. The genomic DNA G + C content of three G. tinctoria rhizobia was in the range from 60.64 to 62.83 mol%. Data for species identification were obtained from DNA–DNA hybridization experiments. G. tinctoria microsymbionts from Poland were classified within Bradyrhizobium japonicum genomospecies based on 56–82% DNA–DNA similarity.  相似文献   

7.
Miscanthus x giganteus bark samples subjected to fractionation by the Acetosolv process under optimal conditions were bleached using hydrogen peroxide and acetic acid in aqueous media under alkaline conditions. The influence of the main operational variables in the bleaching of Acetosolv pulps of M. x giganteus (i.e. hydrogen peroxide concentration, 3–7%; temperature, 55–75 °C; pH 9–11), obtained after treatments, have been assessed on pulp yield, kappa number, viscosity and brightness of bleached pulps. For this purpose, a rotatable and orthogonal second-order factorial design of experiments was used, in order to identify the optimum operating conditions. The obtained empirical mathematical models demonstrate that, in general, the bleaching was efficient, achieving pulps with kappa numbers below 10. The chemical composition and physicochemical properties of the bleached pulps fulfilled the requirements for forthcoming bleaching stages. Moreover, an alkaline extraction stage to eliminate saponifiable groups of Acetosolv pulps was studied, as well as the necessity of use chelating agents in the stage with hydrogen peroxide.  相似文献   

8.
The composition of essential oils hydrodistilled from 19 samples of inflorescences and leaves of Achillea millefolium L. plants, which were transferred from 14 natural habitats in Lithuania to the field collection, is reported. Total content of oil was 0.15–0.55% in inflorescences and 0.06–0.19% (v/w) in leaves. In total 117 compounds were identified positively or tentatively. Data obtained clearly indicate the presence of a remarkable chemical polymorphism within the population of A. millefolium in Lithuania. The content of the major constituents in the oils from inflorescences varied in the following ranges: β-pinene, 0.33–62.29%; β-myrcene, 0.05–69.76%; α-phelandrene, 0.13–29.96%; 1,8-cineole, 2.30–21.57%; and chamazulene, 0.08–30.70%. According to the major components the essential oils' six chemotypes of A. millefolium were defined.  相似文献   

9.
Two Gram-staining-negative, moderately halophilic bacteria, strains M1-18T and L1-16, were isolated from a saltern located in Huelva (Spain). They were motile, strictly aerobic rods, growing in the presence of 3–25% (w/v) NaCl (optimal growth at 7.5–10% [w/v] NaCl), between pH 4.0 and 9.0 (optimal at pH 6.0–7.0) and at temperatures between 15 and 40 °C (optimal at 37 °C). Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that both strains showed the higher similarity values with Chromohalobacter israelensis ATCC 43985T (95.2–94.8%) and Chromohalobacter salexigens DSM 3043T (95.0–94.9%), and similarity values lower than 94.6% with other species of the genera Chromohalobacter, Kushneria, Cobetia or Halomonas. Multilocus sequence analysis (MLSA) based on the partial sequences of atpA, rpoD and secA housekeeping genes indicated that the new isolates formed an independent and monophyletic branch that was related to the peripheral genera of the family Halomonadaceae, Halotalea, Carnimonas and Zymobacter, supporting their placement as a new genus of the Halomonadaceae. The DNA–DNA hybridization between both strains was 82%, whereas the values between strain M1-18T and the most closely related species of Chromohalobacter and Kushneria were equal or lower to 48%. The major cellular fatty acids were C18:1ω7c/C18:1ω6c, C16:0, and C16:1ω7c/C16:1ω6c, a profile that differentiate this new taxon from species of the related genera. We propose the placement of both strains as a novel genus and species, within the family Halomonadaceae, with the name Larsenia salina gen. nov., sp. nov. The type strain is M1-18T (= CCM 8464 = CECT 8192T = IBRC-M 10767T = LMG 27461T).  相似文献   

10.
Petals in three strains of M. falcata L. contain lutein 50–52%, lutein-5,6-epoxide 16–18%, chrysanthemaxanthin 9–10%, flavoxanthin 7–8%, and in smaller amounts β-carotene, ζ-carotene, a hydroxy-α-carotene-like pigment, two neoxanthins, auroxanthin and a flavoxanthin-like pigment. Almost 98% of all carotenoids were xanthophylls esterified with fatty acids. Uniformity of major carotenoid content in the three strains is consistent with their all belonging to the same species.  相似文献   

11.
12.
Polyphenol oxidases are involved in aurone biosynthesis but the gene responsible for 4-deoxyaurone formation in Asteraceae was so far unknown. Three novel full-length cDNA sequences were isolated from Coreopsis grandiflora with sizes of 1.80 kb (cgAUS1) and 1.85 kb (cgAUS2a, 2b), encoding for proteins of 68–69 kDa, respectively. cgAUS1 is preferably expressed in young petals indicating a specific role in pigment formation. The 58.9 kDa AUS1 holoproenzyme, was recombinantly expressed in E. coli and purified to homogeneity. The enzyme shows only diphenolase activity, catalyzing the conversion of chalcones to aurones and was characterized by SDS–PAGE and shot-gun type nanoUHPLC–ESI-MS/MS.  相似文献   

13.
Differentiation of freshly separated (uncultured) and cultured cyanobionts of Azolla species was carried out employing morphological markers and profiles generated using SDS-PAGE and PCR–RFLP of 16S rRNA. The cell dimensions of vegetative cells, heterocysts and heterocyst frequency (25–28%) of the freshly separated cyanobionts were distinctly higher than that those recorded for the cultured cyanobionts (7–10%). The SDS-PAGE profiles of whole cell proteins of cultured cyanobionts (comprising 28–30 bands) and those of freshly separated cyanobionts (consisting of 6–10 bands) exhibited distinct differences and unique bands. AluI was able to discriminate freshly separated cyanobionts from cultured cyanobionts of same species of Azolla. The profiles of cyanobionts (freshly separated and cultured) of A. rubra (RU6503) generated using the restriction enzyme AluI were distinctly different from other cyanobionts and unique bands were observed in both cyanobionts. The cultured cyanobionts from A. microphylla (MI4018), A. filiculoides (FI1001) and A. pinnata (PP7001) showed the presence of a distinct band of 450, 622 and 307 bp, respectively. Three common bands of 500, 400 and 275 bp were recorded in the AluI restriction profiles of all the freshly separated cyanobionts. 16S rRNA PCR–RFLP analyses confirmed the existence of primary and secondary cyanobionts in the leaf cavities of different Azolla species. These techniques can be utilized for discriminating between freshly separated and cultured cyanobionts of Azolla and provide reliable fingerprints for these strains.  相似文献   

14.
Studies on Caulerpa prolifera rhizoids were carried out to determine the possibility of mass culture, because the rhizoids produce a bio-adhesive. Rhizoids can be induced by cutting the base of a blade and floating it in a media or planting it in sand. Measurement of rhizoid production included determination of number, length, and the weight of attached sand grains. The growth experiments were for 1–2 weeks and fronds growth was compared to rhizoid production. Optimal conditions for rhizoid growth included low levels of nitrogen and phosphate (less than 5 and 2 μM, respectively), low irradiance (30 μmol photon m−2 s−1), moderate temperature (22–28°), continuous shaking, addition of microelements and auxin (1 ppm) and initially detached fronds followed by attachment. Under these optimal conditions maximal weekly growth reached 70–170 rhizoids per blade, 7–11 mm length and maximal attachment to sand grains. Blade growth of C. prolifera responded similarly to rhizoid production and reached a weekly growth rate of 30–130%.  相似文献   

15.
Studies investigating the association between interleukin-13 (IL-13) single nucleotide polymorphism (SNP) rs20541 and allergic rhinitis (AR) risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of IL-13 SNP rs20541 with AR risk. Eight studies were included in the present meta-analysis (2153 cases and 3931 controls). The combined results based on all studies showed that IL-13 SNP rs20541 was associated with increased AR risk (Gln versus Arg: odds ratio (OR) = 1.18, 95% confidence interval (CI) = 1.08–1.30; Gln/Gln versus Arg/Arg: OR = 1.52, 95% CI = 1.20–1.92; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.19, 95% CI = 1.06–1.33; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.42, 95% CI = 1.13–1.79). When stratifying for race, IL-13 SNP rs20541 exhibited increased AR risk in Asians (Gln versus Arg: OR = 1.20, 95% CI = 1.06–1.36; Gln/Gln versus Arg/Arg: OR = 1.57, 95% CI = 1.17–2.12; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.22, 95% CI = 1.04–1.44; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.45, 95% CI = 1.09–1.93), while no significant association was detected in Caucasians (Gln versus Arg: OR = 1.28, 95% CI = 0.93 ~ 1.78; Gln/Gln versus Arg/Arg: OR = 1.42, 95% CI = 0.96–2.11; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.35, 95% CI = 0.89–2.05; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.37, 95% CI = 0.93–2.02). This meta-analysis supported that IL-13 SNP rs20541 was associated with AR, particularly in Asians.  相似文献   

16.
Two modes of high-speed counter-current chromatography (HSCCC) were successfully applied to the separation of alkaloids from crude extract of Nelumbo nucifera leaves. The conventional HSCCC separations were performed with a two-phase solvent system composed of tetrachloromethane–CHCl3–methanol–0.1 M HCl at a volume ratio of 1:3:3:2 (v/v/v/v), and 120 mg crude extract could be successfully separated. pH-Zone-refining CCC was performed with a two-phase solvent system composed of petroleum ether (60–90 °C)–ethyl acetate–methanol–water (5:5:2:8, v/v/v/v) where triethylamine (10 mM) was added to the upper organic stationary phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluent. From 4.0 g of the crude extract, 120 mg N-nornuciferine, 1020 mg nuciferine and 96 mg roemerine were obtained in a single run each with a purity of over 98% as determined by HPLC. The structures of the isolated compounds were identified by ESI-MS, 1H NMR and 13C NMR.  相似文献   

17.
The chemical composition of epicuticular waxes of Mandevilla guanabarica and Mandevilla moricandiana was comparatively analyzed by extraction in n-hexane and chloroform. The mean wax content per unit of leaf area in the n-hexane extract was about 13–30 μg cm−2 for M. guanabarica, containing 20–28% n-alkanes and 55–63% triterpenes; for M. mori-candiana, the mean content was 19 μg cm−2, containing 73% n-alkanes and 14% triterpenes. In the chloroform extract, the wax yield was 40–80 μg cm−2 for M. guanabarica, with about 9–11% n-alkanes and 75–82% triterpenes; while for M. moricandiana, the wax yield was 110 μg cm−2, with 52% n-alkanes and 14% triterpenes. The major compounds identified were lupeol, pentacyclic triterpenes of the α- and β-amyrin class, and n-alkanes such as nonacosane, hentriacontane and tritriacontane. These results indicate that the quantitative chemical profiles of epicuticular waxes of M. guanabarica and M. moricandiana are distinct and could be used as an additional feature in taxonomic identification.  相似文献   

18.
This study aimed to assess physicochemical and microbiological properties of fresh spent mushroom substrates (SMSs) – without post-crop heat treatment – from Agaricus subrufescens and Lentinula edodes production to optimize the use of these residues in the soil enrichment for lettuce growth promotion and soil remediation. Organic matter and C content of both SMSs were high. Fresh A. subrufescens SMS was a good source of N, P and K. On the other hand, L. edodes SMS presented a lower concentration of these nutrients and a high level of immaturity. Both SMSs presented high electric conductivity values (2.5–3.4 mS/cm). Microbiological analysis, based upon enumeration of culturable bacteria (thermophilic and mesophilic) and fungi, and also evolution of CO2, showed that SMSs played higher microbial diversity than soil control. Laccase activity from A. subrufescens SMS tended to remain constant during a 2-month period, while L. edodes SMS presented low laccase activity throughout the same period. Agaricus subrufescens and L. edodes were able to grow on a PDA (Potato Dextrose Agar) media supplemented with different concentrations of atrazine (1–50 μg/ml), degraded the herbicide, attaining rates of 35% and 26%, respectively. On experiments of lettuce growth promotion using a soil-based potting media with different SMS rates, 5% and 10% (dw) rates of A. subrufescens SMS resulted in higher lettuce aerial dry weights than the rates of 25% and 40%, the chemical fertilization (NPK) and the control (soil). At 10% supplementation, lettuce aerial dry weight increased 2.2 and 1.3 times compared to the control and the NPK treatment, respectively. Protein content increased along with SMS rates. Fresh A. subrufescens SMS was an excellent supplement for lettuce growth promotion and showed potential for remediation of biocides possibly due to improved microbial diversity and enzymatic activity. Fresh L. edodes SMS was not a good fertilizer, at least under the conditions tested. However, microbiological analysis showed that promising results may be achieved when using fresh L. edodes SMS for soil remediation.  相似文献   

19.
In this study, we have investigated the association between osteoporosis and osteocalcin (BGLAP) − 298 C>T, estrogen receptor 1 (ER1) 397 T>C, collagen type1 alpha 1 (Col1A1) 2046 G>T and calcitonin receptor (CALCR) 1340 T>C polymorphisms. Genomic DNA was obtained from 266 persons (158 osteoporotic and 108 healthy controls). Genomic DNA was extracted from EDTA-preserved peripheral venous blood of patients and controls by a salting-out method and analyzed by PCR-RFLP. As a result, there was no statistically significant difference in the genotype and allele frequencies of patients and controls for BGLAP − 298 C>T, Col1A1 2046 G>T, ER1 397 T>C and CALCR 1340 T>C polymorphisms. However, ER1 CC genotype compared with TT + TC genotypes was found to increase the two fold the risk of osteoporosis [p = 0.039, OR = 2.156, 95% CI (1.083–4.293)] and CALCR CC genotype compared with TT + TC genotypes was found to have protective effect against osteoporosis [p = 0.045, OR = 0.471, 95% CI (0.237–0.9372)]. In the combined genotype analysis, ER1/CALCR TCCC combined genotype was estimated to have protective effect against osteoporosis [p = 0.0125, OR = 0.323, 95% CI (0.1383–0.755)] whereas BGLAP/Col1A1 CCTT and ER1/CALCR CCTT combined genotypes were estimated as risk factors for osteoporosis in Turkish population (p = 0.027, p = 0.009 respectively).  相似文献   

20.
Two related perciform fish species of the subfamily Monotaxinae (Sparoidea: Lethrinidae) Gymnocranius superciliosus sp. nov. and Gymnocranius satoi sp. nov. are described from specimens and tissue samples from the Coral Sea and adjacent regions. G. superciliosus sp. nov. is distinct from all other known Gymnocranius spp. by the following combination of characters: body elongated (depth 2.7–3.1 in standard length), caudal fin moderately forked with a subtle middle notch, its lobes slightly convex inside, distinctive blackish eyebrow, snout and cheek with blue speckles, and dorsal, pectoral, anal and caudal fins reddish. G. satoi sp. nov. is the red-finned ‘Gymnocranius sp.’ depicted in previous taxonomic revisions. While colour patterns are similar between the two species, G. satoi sp. nov. is distinct from G. superciliosus sp. nov. by the ratio of standard length to body depth (2.4–2.5 vs. 2.7–3.1) and by the shape of the caudal fin, which is more shallowly forked, its lobes convex inside and their extremities rounded. The two species are genetically distinct from each other and they are genetically distinct from G. elongatus, G. euanus, G. grandoculis, and G. oblongus sampled from the Coral Sea and adjacent regions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号