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.
2.
Nine new species of the genus Heliura are described from Brazil (H. brasiliana sp. nov., H. olivocolora sp. nov., H. pulcherrima sp. nov., and H. laerteae sp. nov.), Ecuador (H. ecuadoris sp. nov.), Peru (H. flavipennis sp. nov. and H. peruana sp. nov.), and Venezuela (Heliura albiventris sp. nov. and H. juliani sp. nov.). They are illustrated in habitus and genitalia, and their phylogenetic affinities are discussed based on morphological evidence.  相似文献   

3.
Four new species of Alaus Eschscholtz, 1829 are described: A. cinnamomeus n. sp., A. latlpennls n. sp., A. serlceus n. sp. and A. thoracopunctatus n. sp. Three species removed from Chalcolepldlus Eschscholtz, 1829, are transferred to this genus: A. allcll (Pjatakowa, 1941) n. comb., A. haroldl (Candèze, 1878) n.comb. and A. unlcus (Fleutiaux, 1910) n. comb. The characters of external morphology of these seven species and male and female genitalia, when available, are described and illustrated. An identification key for all species of the genus is included: A. allcll (Pjatakowa, 1941) n. comb., A. calcarlpllosus Casari, 1996, A. cinnamomeus n. sp., A. haroldl (Candèze, 1878) n. comb., A. latlpennls n. sp., A. lusclosus (Hope, 1832), A. melanops Leconte, 1863, A. myops (Fabricius, 1801), A. nobllls Sallé, 1855, A. oculatus (Linnaeus, 1758), A. patrlclus (Candèze, 1857), A. plebejus Candèze, 1874, A. serlceus n. sp., A. thoracopunctatus n. sp., A. tricolor (Olivier, 1790), A. unlcus (Fleutiaux, 1910) n. comb., A. veracruzanus Casari, 1996 and A. zunianus Casey, 1893.  相似文献   

4.
Five fluorescent symmetrical dimeric bisbenzimidazoles DB(n) containing four 2,6-substituted benzimidazole cores and differing in the length of the oligomethylene linker between two bisbenzimidazole rings (n = 3, 4, 5, 7, 11) have been synthesized. The ability of the dimeric bisbenzimidazoles to form complexes with the double-stranded DNA has been shown by spectral methods. Upon binding to the double-stranded DNA, DB(n) are localized in the narrow groove. The data on the inhibition of the DNA methyltransferase Dnmt3a by DB(n) indicate that dimeric bisbenzimidazoles DB(3) and DB(11) site-specifically bind to the oligonucleotide duplex.  相似文献   

5.
6.
Abstract

The present paper deals with the synthesis of novel macrocyclic complexes of the type [MLX]X, where [(M?=?Co(II) (1), and Ni(II) (2) X?=?(Cl2)]. The complexes are synthesized by the reaction of ligand(L)diquinolineno[1,3,7,9]tetraazacyclododecine-7,15-ethane(14H,16H)-benzene with the corresponding metal salts. The synthesized complexes are thoroughly characterized by elemental analysis, FT-IR, 1H-NMR, Mass and electronic spectra. The complexes (1) and (2) were evaluated for in vitro cytotoxicity against human breast adenocarcinoma cell (MCF-7). MTT cytotoxicity studies shows both the complexes are most effective. The binding properties of these complexes with calf thymus-DNA were studied by absorption, emission spectra, viscosity measurements, and thermal denaturation studies. On binding to CT-DNA, the absorption spectrum undergoes bathochromic and hypochromic shifts. The absorption spectral results indicate that the intrinsic binding constant (Kb) are 4.8?×?105?M?1 for (1) and 3.9?×?105?M?1 for (2) respectively, suggesting that complex (1) binds more strongly to CT-DNA than complex (2). The viscosity measurement results revealed the viscosity of sonicated rod like DNA fragments increased when the complex was added to the solution of CT-DNA. The synthesized ligand and its metal complexes are screened for antibacterial and antifungal activities.  相似文献   

7.
A new malbrancheamide analogue, isomalbrancheamide B (3), along with three known compounds, malbrancheamide (1), isomalbrancheamide (2), and premalbrancheamide (4), were isolated in higher yields from the alkaloid fraction of the fungus Malbranchea aurantiaca. The interaction of the alkaloids 1–4 with calmodulin (CaM) was analyzed using different enzymatic, fluorescence, spectroscopic, nuclear magnetic resonance (NMR), and molecular modelling techniques. On the basis of the enzymatic and fluorescence experiments, malbrancheamides 1–3 are classical CaM inhibitors. Compound 4, however, did not quench the extrinsic fluorescence of the CaM biosensor indicating that it could be a functional inhibitor. Circular dichroism, NMR, and molecular modelling studies revealed that 1 binds to CaM in the same hydrophobic pocket than the chlorpromazine and trifluoperazine, two classical CaM inhibitors. Thus, malbrancheamide and related monochlorinated analogues are compounds with a high potential for the development of new therapeutic agents, involving CaM as their molecular target.  相似文献   

8.
James L. Reveal 《Brittonia》1976,28(3):337-340
Five new entities ofEriogonum are described from Baja California and Baja California Sur, Mexico, including one species,E. preclarum, and four varieties of other species:E. fasciculatum var.emphereium,E. wrightii var.oresbium,E. elongatum var.areorivum, andE. grande var.testudinum. Three combinations are proposed:E. wrightii var.dentatum,E. elongatum var.vollmeri, andE. repens.  相似文献   

9.
Three new species of Dahlstedtia, D. burkartii, D. dehiscens, and D. lewisiana, are described from South America, and their relationships with related species are discussed. Dahlstedtia burkartii, from Argentina, has pink flowers with standard straight, whereas D. dehiscens and D. lewisiana, both from Brazil, have purplish to lilac flowers with a reflexed standard petal. A new combination, Dahlstedtia peckoltii, is proposed based on Lonchocarpus peckoltii and a neotype is selected for the latter. Information about geographic distribution and phenology of the species is provided.  相似文献   

10.
The geometrical structures, potential energy surface, stability, and bonding character of low-energy isomers of planar C3B3 were systematically explored and investigated at the B3LYP/6-311+G(d)// CCSD(T)/6-311+G(d) level for the first time. A large number of planar structures for low-energy isomers of C3B3 are located and reported. In particular, isomers 1 (Cs,2A’) and 2 (Cs,2A’), with a belt-like structure corresponding to the lowest-energy structures of planar C3B3, are revealed. Based on molecular orbital (MO) and natural bond orbital (NBO) analyses, delocalized σ MOs, multi-centered σ MOs, and delocalized π MOs play an important role in stabilizing the structures of low-energy isomers of C3B3. It is interesting to note from isomerization analysis that the interconversion of isomers 2 and 7 can be realized through two isomerization channels. The results demonstrate that isomers 1, 2, 3, 4, 7, 9, 12, 17, 19, and 20 of C3B3 are stable both thermodynamically and kinetically at the B3LYP/ 6-311+G(d)//CCSD(T)/ 6-311+G(d) level, and that they are observable in the laboratory, which is helpful for future experimental studies of C3B3.  相似文献   

11.
A series of amide chalcones conjugated with different secondary amines were synthesised and characterised by different spectroscopic techniques 1H NMR, 13C NMR, and ESI-MS. They were screened for in vitro antibacterial activity. Compounds 36, 37, 38, 42, and 44 are the most active among the synthesised series exhibiting MIC value of 2.0–10.0?µg/ml against different bacterial strains. Compound 36 was equipotent to the standard drug Ampicillin displaying MBC value of 2.0?µg/ml against the bacterial strain Staphylococcus aureus. The products were screened for anti-biofilm activity. Compounds 36, 37, and 38 exhibited promising anti-biofilm activity with IC50 value ranges from 2.4 to 8.6?µg. Molecular modelling was performed suggesting parameters of signalling anti-biofilm mechanism. AspB327 HisB340 (arene–arene interaction) and IleB328 amino acid residues seemed of higher importance to inhibit c-di-GMP. Hydrophobicity may be crucial for activity. ADME calculations suggested that compounds 36, 37, and 38 could be used as good orally absorbed anti-biofilm agents.  相似文献   

12.
Abstract

Reaction of 2-ethylthioadenine (1) with protected ribose (2) in the presence of stannic chloride gave 2-ethylthioadenosine (4). Oxidation of 5 with potassium permanganate yielded the corresponding sulfone (6) which furnished spongosine (7) after treatment with sodium methoxide. Similarly, reactions of 7-amino-5-ethylthio-1,2,3-triazolo[4,5-d]pyrimidine (8) with the ribose (2) gave 8-azaspongosine (13). The compounds (4) and 7 demonstrated potent antiaggregatory effects both in human platelet-rich plasma and whole blood, whereas, the aza analog (13) showed no inhibitory activity on platelet aggregation. Both (4) and (7) inhibit platelet aggregation in the presence of adenosine deaminase, whereas, adenosine is non-inhibitory, suggesting that analogs (4) and (7) are poor substrates for adenosine deaminase.  相似文献   

13.
Twelve morphologically similar species of Acrapex Hampson 1894, (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina), from Western, Central and Eastern Africa are reviewed. Eight of these species are new to science and are described: Acrapex akunamatata n. sp. and A. incrassata n. sp. from Kenya; A. gracilis n. sp., A. iringa n. sp., A. lukumbura n. sp. and A. rungwe n. sp. from Tanzania; A. soyema n. sp. from Ethiopia; and A. zoutoi n. sp. from Benin. All 12 species belong to a species complex that we hereby define as the Acrapex apicestriata group. Host-plants for three of the new species are recorded: Setaria incrassata (Hochst.) Hack. for Acrapex incrassata; Cymbopogon pospishilii (K. Schum.) C.E. Hubb. for A. rungwe; and Andropogon perligulatus Stapf. for A. zoutoi. We also conducted molecular phylogenetic analyses (using maximum likelihood and Bayesian inference) on a six gene multimarker molecular dataset (four mitochondrial and two nuclear gene fragments; 4581 nucleotides in length) consisting of 15 Acrapex species (including seven species from the apicestriata group) and four outgroups species from the subtribe Sesamiina (from genera Busseola Thurau 1904, Sciomesa Tams & Bowden 1953, Pirateolea Moyal, Le Ru, Conlong, Cugala, Defabachew, Matama-Kauma, Pallangyo & Van den Berg 2010 and Sesamia Boisduval & Guenée 1852). Both maximum likelihood and Bayesian inference analyses yield a similar and well-supported topology, which supports the monophyly of the apicestriata group.  相似文献   

14.
15.
Hammatoderus wappesi n. sp. and H. garciaorum n. sp. are described from Mexico, Veracruz and Oaxaca and Veracruz, respectively. Hammoderus brasiliensis Breuning, 1943 and Plagiohammus camillus Dillon & Dillon, 1949 are proposed as synonyms of Hammatoderus confusor (Dillon & Dillon, 1941); Plagiohammus rotundipennis Breuning, 1950 is proposed as a synonym of Hammatoderus pollinosus (Bates, 1880). A replacement name, Deliathis neonivea nom. nov., for Deliathis nivea (Breuning, 1943) n. comb., a secondary homonym of D. nivea Bates, 1869, is proposed. Three other new combinations are proposed: Deliathis imperatrix (Thomson, 1868) n. comb.; Monochamus sargi (Bates, 1885) n. comb.; and Monochamus blairi (Breuning, 1936) n. comb. Monochamus sargi and Hammatoderus pollinosus are redescribed. Hammatoderus sticticus (Bates, 1874) is newly recorded from Bolivia, with H. confusor newly recorded from Argentina and Colombia and its known distribution in Brazil expanded to include the state of Sao Paulo. Distribution of Deliathis imperatrix in Mexico is expanded to include the state of Morelos. A key to species of Hammatoderus and a key to species of Taeniotesamazonum” group are also provided.  相似文献   

16.
A novel series of bioactive water soluble mixed ligand complexes (1–5) [MII(L)(phen)AcO]. nH2O {where M?=?Cu (1) n?=?2; Co (2), Mn (3), Ni (4), n?=?4 and Zn (5) n?=?2} were synthesized from 2-(2-Morpholinoethylimino) methyl)phenol Schiff base ligand (LH), 1, 10-phenanthroline and metal(II) acetate salt in a 1:1:1 stoichiometric ratio and characterized by several spectral techniques. The obtained analytical and spectral data suggest the octahedral geometry around the central metal ion. Density functional theory calculations have been further supportive to explore the optimized structure and chemical reactivity of these complexes from their frontier molecular orbitals. Gel electrophoresis result indicates that complex (1) manifested an excellent DNA cleavage property than others. The observed binding constants with free energy changes by electronic absorption technique and DNA binding affinity values by viscosity measurements for all compounds were found in the following order (1)?>?(2)?>?(4)?>?(5)?>?(3) > (LH). The binding results and thermodynamic parameters are described the intercalation mode. In vitro antioxidant properties disclose that complex (1) divulges high scavenging activity against DPPH?, ?OH, O2?? NO?, and Fe3+. The antimicrobial reports illustrate that the complexes (1–5) were exhibited well defined inhibitory effect than ligand (LH) against the selected different pathogenic species. The observed percentage growth inhibition against A549, HepG2, MCF-7, and NHDF cell lines suggest that complex (1) has exhibited superior anticancer potency than others. Thus, the complex (1) may contribute as potential anticancer agent due to its unique interaction mode with DNA.GRAPHICAL ABSTRACT

Communicated by Ramaswamy H. Sarma  相似文献   

17.
Rubralactone (1), rubralides A, B and C (24), rubramin (5), and 2-formyl-3,5-dihydroxy-4-methylbenzoic acid (6), were isolated from Penicillium rubrum, and their structures established by spectroscopic methods including 2D NMR. The effects on plant growth of 16 were examined using the lettuce seedling bioassay. Compound 1 promoted root growth. Compounds 2, 3 and 5 inhibited the growth of lettuce seedlings, but 4 and 6 did not have any inhibitory effect on their growth.  相似文献   

18.
Five novel C30 triterpenoids, ganoderic acids Mg (10), Mh (11), Mi (12), Mj (13) and Mk (14), were isolated from the mycelial mat of a G. lucidum strain, which produces C27 lucidenic acids in the fruiting body. Their structures were determined by spectroscopic analysis and chemical conversion.  相似文献   

19.
Paulo H. Labiak 《Brittonia》2011,63(1):139-149
Stenogrammitis , a new genus of grammitid ferns, is segregated from Lellingeria based on morphological and molecular evidence. It differs from Lellingeria by linear leaves usually less than 5 mm wide, clathrate iridescent rhizome scales that are glabrous except for a single apical cilium, veins unbranched and only one per segment, fertile veins usually with the dark sclerenchyma visible beneath the sporangia, and x = 33. In contrast, Lellingeria has broader laminae, veins pinnate within the segments, and fertile veins not visible beneath the sporangia. Melpomene, which is sister to Stenogrammitis and Lellingeria, differs from those two genera by reddish setae on the leaves and rhizome scales papillate at the apex. Some species of Stenogrammitis are also distinctive by hemidimorphic laminae that have the fertile portion less dissected than the sterile. Stenogrammitis is pantropical and currently comprises 24 species, 12 of which occur in the Neotropics, six in Africa, four in Madagascar, and two on Pacific Islands. New combinations are made for Stenogrammitis aethiopica, S. anamorphosa, S. ascensionensis, S. boivinii, S. delitescens, S. jamesonii, S. hartii, S. hellwigii, S. hildebrandtii, S. limula, S. luetzelburgii, S. myosuroides, S. nutata, S. oosora, S. paucipinnata, S. prionodes, S. pumila, S. ruglessii, S. rupestris, S. saffordii, S. strangeana, S. tomensis, S. subcoriacea, and S. wittigiana. Lectotypifications are made for Grammitis muscosa, Polypodium itatiayense, P. oosorum var. micropecten, P. serrulatum forma major, P. serrulatum forma minor, S. luetzelburgii, S. myosuroides, and S. wittigiana. Illustrations are presented for the diagnostic characters of the genus, as well as a map with the geographical distribution.  相似文献   

20.
The current solution to iron-mediated damage in transfusional iron overload disorders is decorporation of excess unmanaged metal, chelation therapy. The clinical development of the tridentate chelator deferitrin (1, Table 1) was halted due to nephrotoxicity. It was then shown by replacing the 4′-(HO) of 1 with a 3,6,9-trioxadecyloxy group, the nephrotoxicity could be ameliorated. Further structure–activity relationship studies have established that the length and the position of the polyether backbone controlled: (1) the ligand’s iron clearing efficiency (ICE), (2) chelator tissue distribution, (3) biliary ferrokinetics, and (4) tissue iron reduction. The current investigation compares the ICE and tissue distribution of a series of (S)-4,5-dihydro-2-[2-hydroxy-4-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 35) and the (S)-4,5-dihydro-2-[2-hydroxy-3-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 810). The three most effective polyether analogues, in terms of performance ratio (PR), defined as mean ICEprimate/ICErodent, are 3 (PR 1.1), 8, (PR 1.5), and 9, now in human trials, (PR 2.2). At the onset of the clinical trial on 9, no data were available for ligand 3 or 8. This is unfortunate, as 3 has many advantages over 9, e.g., the ICE of 3 in rats is 2.5-fold greater than that of 9 and analogue 3 achieves very high levels in the liver, pancreas, and heart, the organs most affected by iron overload. Finally, the impact of 3 on the urinary excretion of kidney injury molecule-1 (Kim-1), an early diagnostic biomarker for monitoring acute kidney toxicity, has been carried out in rats; no evidence of nephrotoxicity was found. Overall, the results suggest that 3 would be a far superior clinical candidate to 9.  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