Institutional Repository of Chengdu Institute of Biology, CAS
Not a member yet
6513 research outputs found
Sort by
Direct and highly stereoselective synthesis of quinolizidine iminosugars promoted by L-proline-Et3N
No full textA mild and effective method for the synthesis of polyhydroxylated quinolizidine iminosugars is described. The Mannich-type reaction of iminosugar C-glycosides with aldehyde in the presence of L-proline-Et3N provides polyhydroxylated quinolizidine iminosugars, and desired products as the potential glucosidase inhibitors were obtained in good to excellent yields with excellent stereoselectivity
Molecular markers and cytogenetics to characterize a wheat-Dasypyrum villosum 3V (3D) substitution line conferring resistance to stripe rust
No full textDasypyrum villosum has been used as a valuable gene resource for disease resistances, yield increase and quality improvement in wheat. A novel wheat-D. villosum alien introgression line CD-3 was generated through hybridization between the common wheat Chinese Spring (CS) and a CS-D. villosum 3V addition line having considerably high stripe rust resistance, which enable the characterization of a potential new stripe rust resistance gene (s) derived from D. villosum. The results of non-denaturing fluorescent in situ hybridization (ND-FISH) showed that CD-3 contained 42 chromosomes, including a 3V chromosome pair, and the absence of both of the 3D chromosomes. PCR-based Landmark Unique Gene (PLUG) molecular marker analysis supported results from the FISH analysis, revealing CD-3 was a wheat-D. villosum 3V (3D) disomic substitution line. Resistant test of stripe rust on 52 plants of F2 generation (CD-3/CS), CD-3, CS and D. villosum have been conducted at seedling stage. 7 plants of F2 generation possessing two 3V chromosomes exhibited high resistance to stripe rust as CD-3 and D. villosum, 10 plants carrying one 3V chromosome and 35 plants without 3V chromosome were susceptive to stripe rust as CS. The result implied the high stripe rust resistance of CD-3 should be controlled by recessive gene(s) originating from D. villosum. To rapidly detect chromosome 3V in the genetic background of wheat, we developed a novel Sequence Characterized Amplified Region (SCAR) marker specific for 3V chromosome based on the sequence of a grain size-related gene DvGS5 in D. villosum, an orthologue of TaGS5 from wheat. The SCAR marker was designated DvGS5-1443, which could successfully amplify a unique 3V-specific fragment in CD-3 and D. villosum, suggesting that this SCAR marker could facilitate targeting the chromosome 3V in the genetic background of wheat for wheat improvement
Suppressed Recombination of Sex Chromosomes Is Not Caused by Chromosomal Reciprocal Translocation in Spiny Frog (Quasipaa boulengeri)
No full textChromosome rearrangements (CRs) are perceived to be related to sex chromosome evolution, but it is a matter of controversy whether CRs are the initial causative mechanism of suppressed recombination for sex differentiation. The early stages of sex chromosome evolution in amphibians may represent intermediate states of differentiation, and if so, they potentially shed light on the ultimate cause of suppressed recombination and the role of CRs in sex chromosome differentiation. In this paper, we showed that sex determination differs among 16 populations of spiny frog (Quasipaa boulengen), in which individuals have normal and rearranged chromosomes caused by reciprocal translocation. In eastern areas, without translocation, genetic differentiation between sexes was relatively low, suggesting unrestricted recombination. In comparison, in western populations that have both normal and translocated chromosomes, a male-heterogametic system and lack of X-Y recombination were identified by male-specific alleles and heterozygote excess. However, such genetic differentiation between sexes in western populations was not directly related to karyotypes, as it was found in individuals with both normal and translocated karyotypes. In the western Sichuan Basin, male-specific and translocation-specific allelic frequency distributions suggested that recombination of sex-differentiation ceased in all populations, but recombination suppression caused by translocation did not exist in some populations. Combined with phylogenetic inference, this indicated that the establishment of sex-linkage had taken place independently of reciprocal translocation, and translocation was not the ultimate cause of sex chromosome differentiation. Furthermore, comparison of the genetic diversity of alleles on Y chromosomes, X chromosomes, and autosomes in western populations showed a reduction of effective population size on sex chromosomes, which may be caused by reciprocal translocation. It indicates that, although it is not the ultimate cause of recombination suppression, reciprocal translocation may enhance sex chromosome differentiation
Hymenasplenium hastifolium sp nov (Aspleniaceae) from a karst cave in western Guangxi, China
No full textA new fern species, Hymenasplenium hastifolium (Aspleniaceae), from a limestone cave in western Guangxi, China, is described and illustrated. Morphological affinities of genus Hymenasplenium are also compared and discussed. The new species is distinguished by the shape of lamina, the venation, and the sorus distribution. Hymenasplenium hastifolium was found at a cave entrance and is currently known only from one population with ca. 50 individuals. It should be classified as Critically Endangered (CR) following IUCN Red List criteria
Ethnobotany of Anti-hypertensive Plants Used in Northern Pakistan
No full textHypertension is one of the most important factors responsible for cardiovascular ailments worldwide. It has been observed that herbal products and alternative herbal therapies played a significant role in decreasing hypertension. The aim of the current study is to provide significant ethnopharmacological information, both qualitative and quantitative on medicinal plants related to hypertension from Northern Pakistan. The documented data were quantitatively analyzed for the first time in this area. A total of 250 participants were interviewed through semi-structured discussions and questionnaires. Quantitative indices including FC (Frequency citation), FIV (Family importance value), RFC (Relative frequency of citation) and DCI (Disease Consensus index) were calculated. A total of 192 plant species, belonging to 77 families were reported to be used in treatment of hypertension in Northern Pakistan. The most dominant life form reported was herbs (54%), with decoction (72 reports) and leaves (55.1%) were commonly utilized plant part. Highest FIV was recorded in Lamiaceae (327 FIV). RFC ranged from 0.08 to 1.08% while DCI varied from 0.233 to 0.000. In this study original data was compared with thirty one previous national and international published papers from neighboring region to compare the medicinal uses and obtain some novel plant species. About 42% of the medicinal plant species were reported for the first time in treatment of hypertension in comparison to these 31 published papers. Different phytochemical activities of antihypertensive plants were also reported from literature. This research work documents the traditional knowledge of medicinal plants usage and provides baseline in designing clinical trials and pharmacological analysis for treatment of hypertension
Cyclodextrin-based host-guest supramolecular hydrogel and its application in biomedical fields
No full textThe cyclodextrin (CD) based host-guest inclusion complexation between cyclodextrins (CDs) and guest moieties has inspired the fabrication of novel supramolecular hydrogels for biomedical applications. From a topology of view, this article reviews the recent developments of two kinds of CD-based supramolecular hydrogels and their applications in biomedical fields respectively. On one hand, supramolecular hydrogels derived from CD-based poly(pseudo)rotaxanes generally displayed thixotropic and reversible properties and have been extensively developed as injectable drug delivery systems. On the other hand, supramolecular hydrogels based on the host-guest interaction between CDs and small guest moieties generally exhibited stimuli-responsive behaviors, typically the release of therapeutic agents. The development of CD-based supramolecular hydrogels provides a new platform for the design of novel biomaterials
Improving biomass and starch accumulation of bioenergy crop duckweed (Landoltia punctata) by abscisic acid application
No full textDuckweed is a valuable feedstock for bioethanol production due to its high biomass and starch accumulation. In our preliminary experiment, we found that abscisic acid (ABA) could simultaneously increase starch and biomass accumulation of duckweed, but the mechanisms are still unclear. The results showed that the biomass production of duckweed reached up to 59.70 and 63.93 g m(-2) in 6 days, respectively, with an increase of 7% (P < 0.05) compared to the control. The starch percentage increased from 2.29% up to 46.18% after 14 days of treatment, with a total of starch level 2.6-fold higher than that of the control. Moreover, the level of endogenous ABA, zeatin-riboside (ZR) and indole-3-acetic acid (IAA) increased, while gibberellins (GAs) decreased. Notably, ABA content in treated samples reached 336.5 mg/kg (fresh weight), which was 7.5-fold greater than that of the control. Importantly, the enzyme activities involved in starch biosynthesis increased while those catalyzing starch degradation decreased after ABA application. Taken together, these results indicated that ABA can promote biomass and starch accumulation by regulating endogenous hormone levels and the activity of starch metabolism related key enzymes. These results will provide an operable method for high starch accumulation in duckweed for biofuels production
Super Tough, Ultrastretchable Hydrogel with Multistimuli Responsiveness
No full textThe research of hydrogels has been increasingly focused on designing an effective energy dissipation structure in recent years. Here, we report a kind of novel supramolecular cross-linker, which was formed by self-assembling amphiphilic block copolymers with guest groups at the end and vinyl-functionalized cyclodextrin (CD) through host guest interaction. These cross-linkers could dissipate energy effectively since they combined multiple sacrificial mechanisms across multiscales through physical interactions. The resulted hydrogel shows distinguishing mechanical properties (fracture toughness of 2.68 +/- 0.69 MJ/m(3), tension strength of up to 475 kPa, uniaxial stretch over 2100%), remarkable fatigue resistance, and thermal- and light-responsive behaviors
A facile method for the synthesis of fused perhydropyrano[2,3-b]pyrans promoted by Yb(OTf)(3)
No full textA stereospecific three-component domino reaction between glycals, alkylidene malonate and aldehydes catalyzed by Yb(OTf)(3) is described. Multi-substituted cis-fused perhydropyrano[2,3-b]pyran derivatives were obtained with high diastereoselectivity
