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1.
Synthesis of 2,2,3-tris(hydroxymethyl)methylenecyclopropane analogues 16a, 16b, 17a, and 17b is described. Diethyl ester of Feist's acid 18b was hydroxymethylated via carbanion formation using formaldehyde under simultaneous isomerization to cis diester to give intermediate 19. Reduction followed by acetylation gave triacetate 22. Addition of bromine afforded reagent 23, which was used for alkylation-elimination of adenine and 2-amino-6-chloropurine to provide Z,E-isomeric mixtures of 24a and 24b. Deacetylation and separation furnished the Z-isomers 16a, 16c and E-isomers 17a, 17c. Hydrolytic dechlorination of 16c and 17c gave guanine analogues 16b and 17b. None of the analogues exhibited a significant antiviral activity. Adenosine deaminase is refractory toward adenine analogues 16a and 17a. 相似文献
2.
Michael Kessler Ana Laura Moguel Velázquez Michael Sundue Paulo H. Labiak 《Brittonia》2011,63(2):233-244
Alansmia, a new genus of grammitid ferns is described and combinations are made for the 26 species known to belong to it. Alansmia is supported by five morphological synapomorphies: setae present on the rhizomes, cells of the rhizome scales turgid, both
surfaces of the rhizome scales ciliate, laminae membranaceous, and sporangial capsules setose. Other diagnostic characters
include pendent fronds with indeterminate growth, concolorous, orange to castaneous rhizome scales with ciliate or sometimes
glandular margins, hydathodes often cretaceous, and setae simple, paired or stellate. The group also exhibits the uncommon
characteristic of producing both trilete and apparently monolete spores, sometimes on the same plant. New combinations are
made for Alansmia alfaroi, A. bradeana, A. canescens, A. concinna, A. contacta, A. cultrata, A. dependens, A. diaphana, A. elastica, A. glandulifera, A. heteromorpha, A. immixta, A. kirkii, A. lanigera, A. laxa, A. longa, A. monosora, A. reclinata, A. semilunaris, A. senilis, A. smithii, A. spathulata, A. stella var. stella, A. stella var. flava, A. turrialbae, A. variabilis, A. xanthotrichia. Lectotypifications are made for Alansmia concina, A. variabilis, Polypodium ciliare, P. flexile, and P. ovalescens. The genus is named in honor of pteridologist Alan R. Smith. 相似文献
3.
Amalraj Ambrose Jiri Zemlicka Earl R. Kern John C. Drach Elizabeth Gullen Yung-Chi Cheng 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1763-1774
The Z- and E-thymine and cytosine pronucleotides 3d, 4d, 3e, and 4e of methylenecyclopropane nucleosides analogues were synthesized, evaluated for their antiviral activity against human cytomegalovirus (HCMV), herpes simplex virus 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human immunodeficiency virus type 1 (HSV-1), and hepatitis B virus (HBV) and their potency was compared with the parent compounds 1d, 2d, 1e, and 2e. Prodrugs 3d and 4d were obtained by phosphorylation of parent analogues 1d or 2d with reagent 8. A similar phosphorylation of N4-benzoylcytosine methylenecyclopropanes 9a and 9b gave intermediates 11a and 11b. Deprotection with hydrazine in pyridine–acetic acid gave pronucleotides 3e and 4e. The Z-cytosine analogue 3e was active against HCMV and EBV. The cytosine E-isomer 4e was moderately effective against EBV. 相似文献
4.
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
5.
Karim Christina Scopinho Furquim Gervásio Henrique Bechara Maria Izabel Camargo Mathias 《Experimental & applied acarology》2010,50(1):59-70
This study describes the changes undergone by cells of the salivary glands of unfed and feeding (at day two and four post-attachment)
Rhipicephalus sanguineus males, as well as new cell types. In unfed males, types I and II acini are observed with cells “undifferentiated”, undefined
1 and 2 (the latter, with atypical granules), a, c1 and c3; type III is composed of cells d and e; and type IV present cells g. In males at day two post-attachment, type I acini exhibit the same morphology of unfed individuals. An increase in size
is observed in types II, III, and IV, as cells are filled with secretion granules. Some granules are still undergoing maturation.
In type II acinus, cells a, b and c1–c8 are observed. Cells c7 and c8 are described for the first time. Cells c7 are termed as such due to the addition of polysaccharides in the composition of the secretion granules (in unfed individuals,
they are termed undefined
1). Type III acini exhibit cells d and e completely filled with granules, and in type IV, cells g contain granules in several stages of maturation. In males at day four post-attachment, type I acini do not exhibit changes.
Granular acini exhibit cells with fewer secretion granules, which are already mature. In type II acini, cells a, b, c1–c5 are present, type III exhibit cells d and e, and type IV contain cells g with little or no secretion. This study shows that in the salivary glands of R.
sanguineus males, cells a, c1, and c3 of type II acinus, and cells d and e of type III do not exhibit changes in granular content, remaining continuously active during the entire feeding period. This
indicates that during the intervals among feeding stages, gland cells reacquire the same characteristics found in unfed individuals,
suggesting that they undergo reprogramming to be active in the next cycle. 相似文献
6.
Véronique Faivre-Buet Annie Grouiller Gérard Descotes 《Nucleosides, nucleotides & nucleic acids》2013,32(7):1411-1424
Abstract Various routes to the targets 1, 2, 3, 1-deoxy-psicofuranosyl nucleoside analogues related to anti-HIV agents, are reported. Two routes afforded their 6′-benzylated derivatives 9, 10 and 15. Only the epoxide 12 and deoxynucleosides 19 and 22 were able to be deprotected leading in the first case to 16 and its ring opening derivative 17 and in the second case to 20 and to the target 3. 相似文献
7.
Hyoung Jae Lee Bunta Watanabe Masaru Nakayasu Michio Onjo Yukihiro Sugimoto 《Bioscience, biotechnology, and biochemistry》2017,81(12):2253-2260
Fifteen steroidal saponins 1–15, which include 4 furostanol glycosides 1–3 and 15, and 11 spirostanol glycosides 4–14, were isolated from the tubers and leaves of lesser yam (Dioscorea esculenta, Togedokoro). Their structures were identified by nuclear magnetic resonance and liquid chromatography mass spectroscopy. Four steroidal saponins 9, 11, 14, and 15 were found to be novel compounds. 相似文献
8.
《Nucleosides, nucleotides & nucleic acids》2013,32(3):161-172
A useful route is described for obtaining Z and E unsaturated alkylating agents 3 and 4. Coupling 6-azauracils 5 and 6 with unsaturated alkylating agent followed by the deprotection with H+ resin gave acyclonucleosides 11–14 in good overall yields. Unsaturated acyclonucleosides phosphonates 19 and 20 were prepared using potassium carbonate as base and 4-bromobut-2-enyl diethyl phosphonate 16 as the alkylating agent. The introduction of a propargyl group at the N-3 position of acyclonucleosides 7, 8, 17, 18, 19, and 20 was achieved using potassium carbonate in DMF. 相似文献
9.
《Nucleosides, nucleotides & nucleic acids》2013,32(8):1555-1569
Two simple regiospecific methodologies based on triazolic ring construction in the course of synthesis were applied for the synthesis of 1,2,3-triazolic nucleoside analogues. The cycloaddition reactions between diazomalonaldehyde and appropriate glycosylamine derivatives were rather effective, producing the desired nucleosides 11, 17 and 24. Diazotization of enamines 21a and 21b led to the corresponding triazolic ribonucleoside derivatives 22a and 22b, in good yields. Deprotection reaction of 22a, 22b and 24 was easily achieved by Lewis acid catalysis, producing the corresponding ribonucleosides 23a, 23b and 25. 相似文献
10.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):593-600
A series of novel carbazole chalcones has been synthesised and evaluated for radical scavenging activity, cytotoxicity and antimicrobial activities. Compounds 12m, 12o and 12c exhibited good 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, compounds 12e, 12m and 12d were excellent hydroxyl radical scavengers and compounds 12a, 12e, 12g, 12n and 12m have shown inhibition of oxidative DNA damage induced by 2,2′-azobis (2-amidinopropane hydrochloride). Compounds 12j, 12i, 12n, 12c, 12m and 12e were most active against the selected cancer cell lines. Compounds 12a, 12e and 12m showed good antibacterial activity and compounds 12h and 12m have shown good antifungal activity. All the compounds were subjected for absorption, distribution, metabolism and excretion (ADME) predictions by computational method and found that these molecules could be considered as potential candidates for oral drug development. 相似文献
11.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1896-1901
Rubralactone (1), rubralides A, B and C (2–4), 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 1–6 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
12.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):267-274
Claisen-Schmidt condensation of 3-(1,2,3,6-tetrahydro-1-methylpyridin-4-yl)-2,4,5- trimethoxybenzaldehyde 3 and various aromatic, heterocyclic and alicyclic amides of 3- aminoacetophenone 6(a–s) afforded novel curcumin mimics. All the synthesized compounds were characterized by IR, 1H NMR, Mass spectroscopy and evaluated for antioxidant, cytotoxicity and antimicrobial activity. Out of the 20 compounds screened, compounds 7i, 7l, 7q, and 7n have shown excellent radical scavenging activity, compounds 7o, 7t, 7f, and 7r have shown significant xanthine oxidase inhibition, and compounds 7a, 7k and 7l were found to be potent inhibitors of selected cancer cell lines. Compounds 7h, 7t, 7l, 7i, and 7e have shown good antibacterial activity, whereas compounds 7j, 7f, 7o, 7h, and 7t exhibited significant antifungal activity. 相似文献
13.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
14.
Summary Two plant communities, both dominated by Carex sempervirens but growing at different altitudes of the Northern Calcareous Alp region (IS: 600 m; KS: 1200 m) and one Carex ferruginea — dominated community (KC: 1200 m) are compared as to changes in dry matter, nitrogen, phosphorus, and potassium content of living and dead overground and underground phytomass.The soils of the montanic sites KS and KC are better provided with water and the three nutrients than that of the prealpine site IS. KC has the highest potassium content in the soil and in the phytomass.The dry matter increase (g/m2) of the living overground phytomass during the growing season is about 200 in IS, 360 in KS, and 340 in KC with maxima of 365 in IS, 550 in KS and 375 in KC.The increase of dead overground phytomass is highest in KS, indicating that the total annual overground production exceeds the mere increase in living parts. Furthermore, there is an increase of underground phytomass in KS and KC. The average ratio of total underground/living overground phytomass is 4.6 in IS, 3.7 in KS, but 7.5 in KC.The annual fluctuation of nitrogen (g/m2) in the living overground phytomass increases from 2.5 in IS to 3.8 in KS and to 5.9 in KC. For KS and KC these values approach the nitrogen mineralization values of the soils observed during the growing season. There is an obvious increase of nitrogen in the underground phytomass of KS and KC toward the end of the growing season. It is concluded that in KC, there is a more pronounced annual oscillation of nitrogen between overground and underground phytomass, which is not observed in IS, and which in KS is intermediate. 相似文献
15.
Adel A.-H. Abdel-Rahman Abd-Allah SH. El-Etrawy Ahmed E.-S. Abdel-Megied Ibrahim F. Zeid El Sayed H. El Ashry 《Nucleosides, nucleotides & nucleic acids》2013,32(12):1257-1271
Regioselective alkylation of 2-thiouracils 1a–c and 4-thiouracils 7a,b with 2,3-O-isopropylidene-2,3-dihydroxypropyl chloride (2) afforded 2-{[(2,2-Dimethyl-1,3-dioxolan-4-yl) methyl]thio}pyrimidin-4(1H)-ones 3a–c and 4-{[(2,2-Dimethyl-1,3-dioxolan-4-yl)methyl]thio} pyrimidin-2(1H)-ones 8a,b, respectively. Further alkylation with 2 and/or 2,3-O-isopropylidine-1-O-(4-toluenesulfonyl)-glycerol (4) gave the acyclo N-nucleosides 5a–c and 9a,b whose deprotection afforded 6a–c and 10a,b. 2-(Methylthio)pyrimidin-4(1H)-ones 11a–c and 4-(methylthio)pyrimidin-2(1H)-ones 14a,b were treated with 2 and/or 4 to give 12a–c and 15a,b which were deprotected to give 13a–c and 16a,b. Pyrimidine-2,4(1H,3H)-dithiones 17a–c were treated with two equivalents of 2 to give 2,4-bis{[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl]thio}pyrimidines 18a–c. Deprotection of compounds 18a–c gave 2,4-bis[(2,3-dihydroxypropyl)thio]pyrimidines 19a-c. The activity of the deprotected nucleosides against Hepatitis B virus was evaluated and showed moderate inhibition activity against HBV with mild cytotoxicity. 相似文献
16.
Kosaku Hirota Yasunari Monguchi Hironao Sajiki Chizuko Yatome Akio Hiraoka Yukio Kitade 《Nucleosides, nucleotides & nucleic acids》2013,32(8):1333-1345
Abstract In expectation of discovering their antiviral activity, acyclic adenosine derivatives 7, 11, 12, and 16 were designed as analogs of neplanocin A (NPA) and L-eritadenine which are strong inhibitors of S-adenosyl-L-homocysteine hydrolase. The 1′,5′-seco-analog of 4′-deoxymethyl-NPA (DHCA) 7 was synthesized by dideoxygenation of 9-(2,3-O-isopropylidene-D-ribityl)adenine (2). Acyclic DHCA analogs 11 and 16 were obtained by Wittig reaction of the aldehyde 3 with Ph3P=CHCO2Et and Ph3P=CHCN, respectively. Hydrolysis of the ester 11 afforded a vinylog of L-eritadenine 12. The synthesized acyclic nucleosides 7, 10, and 11 were evaluated for antiviral activity, however, none of them showed any significant antiviral activity. 相似文献
17.
Walaa M. El-Husseiny Magda A.-A. El-Sayed Esam R. Ahmed Alaa A.-M. Abdel-Aziz 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):507-518
New α,β-unsaturated ketones 4a,b; 5a–c; and 6a,b; as well as 4-H pyran 7; pyrazoline 8a,b; isoxazoline 9; pyridine 10–11; and quinoline-4-carboxylic acid 12a,b derivatives were synthesized and evaluated for in vitro antitumour activity against HepG2, MCF-7, HeLa, and PC-3 cancer cell lines. Antioxidant activity was investigated by the ability of these compounds to scavenge the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS?+). Compounds 6a, 6b, 7, and 8b exhibited potent antitumour activities against all tested cell lines with [IC50] ?5.5–18.1 µΜ), in addition to significantly high ABTS?+ scavenging activities. In vitro EGFR kinase assay for 6a, 6b, 7, and 8b as the most potent antitumour compounds showed that; compounds 6b, and 7 exhibited worthy EGFR inhibition activity with IC50 values of 0.56 and 1.6?µM, respectively, while compounds 6a and 8b showed good inhibition activity with IC50 values of 4.66 and 2.16?µM, respectively, compared with sorafenib reference drug (IC50?=?1.28?µM). Molecular modelling studies for compounds 6b, 7, and 8b were conducted to exhibit the binding mode towards EGFR kinase, which showed similar interaction with erlotinib. 相似文献
18.
《Nucleosides, nucleotides & nucleic acids》2013,32(10-11):1797-1810
The chemical synthesis of some 4-substituted 1-[1-(2-hydroxyethoxy)methyl-1,2,3-triazol-(4 and 5)-ylmethyl]-1H-pyrazolo[3,4-d]pyrimidines 12a,b, 13a,b and 14–23 as acyclic nucleosides is described. Treatment of (2-acetoxyethoxy)methylbromide with sodium azide afforded (2-acetoxyethoxy)methylazide 9. The heterocycles 6a,b were alkylated, separately, with propargyl bromide to obtain, regioselectively, 4-(methyl and benzyl)thio-1-(prop-2-ynyl)-1H-pyrazolo[3,4-d]pyrimidines 7a,b. These N1-alkylated products were condensed with compound 9 via a 1,3-dipolar cycloaddition reaction to obtain, after separation and deprotection, 1,4 and 1,5-regioisomers 12a,b and 13a,b. The deprotected acyclic nucleosides 12a and 13a served as precursors for the preparation of 4-amino (14 and 15), 4-methylamino (16 and 17), 4-benzylamino (18 and 19), 4-methoxy (20 and 21) and 4-hydroxy (22 and 23) analogues. Compounds 7a,b and all deprotected acyclic nucleosides were evaluated for their inhibitory effects against the replication of HIV-1(IIIB) and HIV-2(ROD) in MT-4 cells and for their anti-tumor activity. No marked activity was found. However, initial evaluation of 6a,b, 7a,b, 12a,b, 13a,b and 14–23 showed that compound 7b has marked activity against M. tuberculosis. 相似文献
19.
Akira Tanaka Hirotoshi Kamata Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(8):2043-2048
A novel synthesis of the enone 12 starting from (+)-dihydrocarvone (3) and its transformation into (+)-7-hydroxycostal (1) are described. The ketone 10, obtained from 4 through a four-step sequence was converted to 12 by acid-catalyzed elimination and subsequent regioselective hydrogenation. Alternatively, the methoxyhydroperoxide 13 generated by the ozonolysis of 4 was subjected to the Criegee rearrangement, providing a mixture of 10 and 14, which on acid treatment, gave 11. Transformation of 12 into 19 was accomplished via a five-step reaction sequence. The reaction of 19 with the lithium alkoxide of 2-lithio-2-propenol afforded (+)-7-hydroxycostol (2), whose oxidation with manganese dioxide gave rise to (+)-7-hydroxycostal (1). 相似文献
20.
E. S. H. El Ashry A. A. Kassem H. Abdel-Hamid F. F. Louis Sh. A. N. Khattab M. R. Aouad 《Nucleosides, nucleotides & nucleic acids》2013,32(5):437-451
Regioselective alkylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole (1) with hydroxy alkylating agents 2, 3, 13, and the 2,3-O-isopropylidene-1-O-(p-tolylsulfonyl)-glycerol (10) afforded the corresponding S-alkylated derivatives 6, 7, 11, and 14 under both conventional and microwave irradiation conditions; bentonite as a solid support gave better results, with no change in regioselectivity. A facile intramolecular dehydrative ring closure of 6, 7, 11, and 14 using K2CO3 in DMF afforded the corresponding fused triazolo-thiazines and thiazolo-triazole 17–19. The isopropylidenes and acetyl derivatives of the products were prepared. 相似文献