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1.
A toxic diterpenoid diester and a monoester were isolated from the fruits of Aleurites fordii. The structure of the monoester was found to be 13-O-acetyl-16-hydroxyphorbol by transforming it into bisdehydrophorbol-(12,20)-diacetate. The structure of the toxic constituent was established as 12-O-palmityl-13-O-acetyl-16-hydroxyphorbol by partial synthesis from the monoester.  相似文献   

2.
周杰  陈俊愉 《植物研究》2010,30(6):649-650
报道了中国菊属(Chrysanthemum)一新变种——阔叶毛华菊(Chrysanthemum vestitum(Hem sl.)Stapf.var.latifolium J.Zhou et J.Y.Chen)。本变种与模式变种的区别在于直立生长,并且较多分枝,叶较狭,卵状披针形或匙形,长4~6 cm,宽2~3 cm。花序直径较原种为小,约3.5~4.5 cm。主要分布于湖北宜昌、河南伏牛山山脉。抗旱性较原变种强。而主要原产于安徽西部大别山麓之模式变种则铺散生长,较少分枝,叶圆形、卵圆形,长4~7cm,宽3~5 cm。花序直径较大,约4.5~5.0 cm。  相似文献   

3.
Six taxa of western North American denticulate leaved junipers were collected and their volatile leaf oils analysed. Two chemical forms of J. californica (‘A’ and ‘B’) previously reported were found to differ considerably in their concentration of α-pinene, sabinene, β-pinene, camphor and 4-terpineol. However, principal co-ordinate analysis revealed that the chemical forms of J. californica were the most similar taxa in the group and considerably more similar than the two varieties of J. occidentalis are to each other. This group of junipers appears to consist of two major subgroups: (1) J. occidentalis; and (2) J. california, J. monosperma, J. osteosperma; with J. osteosperma being closely related to the northern form of J. californica (:A.) and J. monosperma being most closely related to the southern form of J. californica (‘B’).  相似文献   

4.
祝正银  祝世杰 《植物研究》2008,28(3):257-258
描述了四川峨眉山茜草科(玉叶金花属)一新种,即峨眉玉叶金花。  相似文献   

5.
描述了四川夹江(兰科)石斛属植物一新种,即夹江石斛。  相似文献   

6.
中国杏属一新种   总被引:5,自引:1,他引:4  
描述了中国杏属一新种,华仁杏(Armeniaca cathayanaD.L.Fu,B.R.Li et J.H.Li,sp.nov.)。该新种与杏(Armeniaca vulgarisLam.)和山杏(A.sibirica(L.)Lam.)相似,但又有其独特特征,主要区别如下:叶两面疏被短柔毛,边缘具单锯齿和重锯齿,基部全缘;叶柄无腺体;单花或2~3朵花簇生;子房密被白色长柔毛;果核三角状卵球形,腹缝线具5~7条锐纵棱,背缝线具1条浅纵沟;种子大,两侧压扁,种仁质脆,无苦味。该新种由傅大立于2008年7月11日在河北省涿鹿县发现并采集,模式标本存于中国林业科学研究院(CAF),标本号:No.2008071101。  相似文献   

7.
发表了产于云南西部的香竹属一新种御香竹(Chimonocalamus cibarius Yi et J. Y. Shi)。  相似文献   

8.
报道了中国蓼属两新种。蜀蓼(Polygonum shuense)与大理蓼(P.subscapsum)相似,但基生叶的基部渐狭,沿叶柄下延,边缘具圆齿,花白色,花柱3,离生,瘦果长卵形,无光泽可以区别。察隅蓼(P.chayuum)产西藏,这个新种的茎不分枝,自基部至中部无叶,仅有托叶鞘,叶着生于茎的上部,这些特征奇特,明显不同于其它种类。  相似文献   

9.
From roots of Peddiea volkensii (Thymelaeaceae) the irritant factors V1 and V2 and from roots of P. africana the irritant factor A1 were isolated. Their structures are the 9,13,14-ortho-(2,4,6-decatrienoates) of 5β-hydroxyresiniferonol-6α,7α-oxide (V1) and of 5β,12β-dihydroxyresiniferonol-6α,7α-oxide (A1) and the 12-O-acetate of the latter (V2). Factors V1 and V2 do not exhibit tumour-promoting activity in the standard initiation-promotion protocol on mouse skin, although V1 is a moderate irritant.  相似文献   

10.
The trail-following behaviour of male Lycosa rabida and L. punctulata (in response to draglines of females) was analysed by high-speed cinematography (36 to 180 frames/s). L. rabida exhibited two modes of following, while L. punctulata showed three modes. One mode, palpal-sliding, was common to both species. During all modes of trail-following both species utilized the medial surface of the palpal tarsus, the surface having the highest concentration of chemosensitive sensilla. Film analyses suggested that male L. rabida used mechanical cues more than did L. punctulata. A significantly higher number of chemosensitive sensilla in male L. punctulata was related to this species's greater reliance on chemical rather than mechanical cues, the reverse being true in L. rabida. Different micro-habitat preferences of the two species may have shaped the differential use of cues for trail-following.  相似文献   

11.
Oxygen-18 exchange out of [18O]Pi catalyzed by Mg2+-activated unadenylated glutamine synthetase from E.coli was followed by 31P-NMR in the presence of the other substrates, ADP and L-glutamine. The pattern of the 16O18O in the species P18O4, P18O316O1, P18O216O2, P18O116O3, P16O4 during the exchange followed a binomial distribution consistent with indiscriminate removal of any of the four oxygens of Pi. The rate constant for 16O18O exchange was 410±40 min?1 while the rate constant for net reaction (ATP formation) was 62±4 min?1. Thus exchange proceeds ~7 times faster than net reaction, a finding in accord with that of Stokes and Boyer (J.Biol.Chem. (1976) 251, 5558) for the Mn2+-activated adenylylated glutamine synthetase. A model for the overall catalytic events first derived from rapid kinetic fluorescence experiments (Rhee and Chock, Proc. Natl. Acad. Sci. USA, (1976) 73, 476) was successfully used to fit the oxygen exchange data in this paper.  相似文献   

12.
The DBA/2J strain is a model for early-onset, progressive hearing loss in humans, as confirmed in the present study. DBA/2J mice showed progression of hearing loss to low-frequency sounds from ultrasonic-frequency sounds and profound hearing loss at all frequencies before 7 months of age. It is known that the early-onset hearing loss of DBA/2J mice is caused by affects in the ahl (Cdh23ahl) and ahl8 (Fscn2ahl8) alleles of the cadherin 23 and fascin 2 genes, respectively. Although the strong contributions of the Fscn2ahl8 allele were detected in hearing loss at 8- and 16-kHz stimuli with LOD scores of 5.02 at 8 kHz and 8.84 at 16 kHz, hearing loss effects were also demonstrated for three new quantitative trait loci (QTLs) for the intervals of 50.3–54.5, 64.6–119.9, and 119.9–137.0 Mb, respectively, on chromosome 5, with significant LOD scores of 2.80–3.91 for specific high-frequency hearing loss at 16 kHz by quantitative trait loci linkage mapping using a (DBA/2J × C57BL/6J) F1 × DBA/2J backcross mice. Moreover, we showed that the contribution of Fscn2ahl8 to early-onset hearing loss with 32-kHz stimuli is extremely low and raised the possibility of effects from the Cdh23ahl allele and another dominant quantitative trait locus (loci) for hearing loss at this ultrasonic frequency. Therefore, our results suggested that frequency-specific QTLs control early-onset hearing loss in DBA/2J mice.  相似文献   

13.
发表了产于云南西部的玉山竹属一新种永德玉山竹(Yushania yongdeensis Yi et J. Y. Shi)。补充记载了雪山箭竹(Fargesia lincangensis Yi)的花部特征。  相似文献   

14.
Marine macroalgae surfaces constitute suitable substrata for bacterial colonization which are known to produce bioactive compounds. Thus, hereby we focused on heterotrophic aerobic bacteria species associated with coralline red alga Jania rubens (northern coast of Tunisia, southern Mediterranean Sea) and their inhibition against several microbial marine and terrestrial species. The whole collection (19 isolates, J1 to J19) was identified, based on their 16S ribosomal RNA gene sequences as Proteobacteria (14 strains), Bacteroidetes (4 strains) and Firmicutes (1 strain). Thirty-six percent of the isolates (J2, J9, J11, J13, J16, J17 and J18) were antibiotic-like producers with in vitro inhibition against Gram + and Gram ? bacteria and the yeast Candida albicans. Highest level of inhibition was revealed for the isolates J2, J9 and J13 identified respectively as Bacillus, Aquimarina and Pseudomonas, with strong activity against Staphylococcus aureus, Micrococcus and C. albicans, with inhibition diameters of 25 to 35 mm shown by drop test assay on T soy agar plates. Furthermore, we tested inhibition of J. rubens crude organic extracts against human and marine bacteria as well as against all J. rubens isolates, in order to determine the degree of affinity of the epibionts to their proper host. The recovery of strains with antimicrobial activity suggests that J. rubens represent an ecological niche which harbors a specific microbial diversity worthy of further secondary metabolites investigation.  相似文献   

15.
Meloidogyne sp. from five pecan (Carya illinoensis) orchards in Texas were distinctive in host range and iszoyme profiles from common species of Meloidogyne but were morphologically congruent with Meloidogyne partityla Kleynhans, a species previously known only in South Africa. In addition to pecan, species of walnut (Juglans hindsii and J. regia) and hickory (C. ovata) also were hosts. No reproduction was observed on 15 other plant species from nine families, including several common hosts of other Meloidogyne spp. Three esterase phenotypes and two malate dehydrogenase phenotypes of M. partityla were identified by polyacrylamide gel electrophoresis. Each of these isozyme phenotypes was distinct from those of the more common species M. arenaria, M. hapla, M. incognita, and M. javanica.  相似文献   

16.
报道了中国兰科植物一新记录种:双眼带叶兰(Taeniophyllum biocellatum J. J. Sm.),并提供特征描述和彩色图片。该种与近缘种的区别特征为花序柄和花序柄苞片浅绿色,根呈圆柱形,花序短;紫红色药帽的中间具2个黄色小点,唇瓣开口大,萼片和花瓣黄绿色。  相似文献   

17.
Eight non-irritant macrocyclic diterpene esters of the jatrophane type were obtained from an irritant acetone extract of latex and from an irritant methanol extract of roots of Euphorbia characias. They were shown to be diesters of the new parent alcohols characiol, characiol-5β,6β-oxide and 5β-hydroxyisocharaciol and pentaesters of 2,5β,8-trihydroxyisocharaciol.  相似文献   

18.
Understanding the interactions of plant-parasitic nematodes with antagonistic soil microbes could provide opportunities for novel crop protection strategies. Three arable soils were investigated for their suppressiveness against the root knot nematode Meloidogyne hapla. For all three soils, M. hapla developed significantly fewer galls, egg masses, and eggs on tomato plants in unsterilized than in sterilized infested soil. Egg numbers were reduced by up to 93%. This suggested suppression by soil microbial communities. The soils significantly differed in the composition of microbial communities and in the suppressiveness to M. hapla. To identify microorganisms interacting with M. hapla in soil, second-stage juveniles (J2) baited in the test soil were cultivation independently analyzed for attached microbes. PCR-denaturing gradient gel electrophoresis of fungal ITS or 16S rRNA genes of bacteria and bacterial groups from nematode and soil samples was performed, and DNA sequences from J2-associated bands were determined. The fingerprints showed many species that were abundant on J2 but not in the surrounding soil, especially in fungal profiles. Fungi associated with J2 from all three soils were related to the genera Davidiella and Rhizophydium, while the genera Eurotium, Ganoderma, and Cylindrocarpon were specific for the most suppressive soil. Among the 20 highly abundant operational taxonomic units of bacteria specific for J2 in suppressive soil, six were closely related to infectious species such as Shigella spp., whereas the most abundant were Malikia spinosa and Rothia amarae, as determined by 16S rRNA amplicon pyrosequencing. In conclusion, a diverse microflora specifically adhered to J2 of M. hapla in soil and presumably affected female fecundity.  相似文献   

19.
Four new species ofJacaranda have been found in the coastal mountain-ranges of SE-Brazil where they occupy characteristic ecological positions.J. montana andJ. subalpina are related toJ. puberula agg.,J. pulcherrima shows affinities toJ. ulei but also toJ. subalpina. J. crassifolia is very distinct and possibly related toJ. obovata.
  相似文献   

20.
中国荞麦属(蓼科)一新种——密毛野荞麦   总被引:1,自引:0,他引:1  
描述了蓼科一新种——密毛野荞麦(Fagopyrum densovillosum J. L. Liu),本种与细柄野荞麦(F. gracilipes(Hemsl.) Damm. et Diels)相近似,不同在于植株全体密被白色直立长毛,茎枝较粗壮,节较密集,节间较短, 叶较大,长(0.9~)1.7~6 cm,宽(0.7~)1.2~5.1 cm,阔卵形,心形,阔心形,阔卵状心形,卵形,长卵形,三角状卵形或卵状三角形,在上面具细皱纹,明显小泡状突起,叶柄较长,长 (0.5~) 2.6~7.5 cm,果实较小,长1.8~2.5 mm,直径1.5~2 mm,易于区别。  相似文献   

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