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1.
Synthetic studies of annonaceous acetogenins starting from (?)-muricatacin (1a) or (+)-muricatacin are described, involving (?)-muricatacin (1a), mono-THF acetogenin, solamin (2), reticulatacin (3), (15R, 16R, 19S, 20S)-cis-solamin (4a) and (15S, 16S, 19R, 20R)-cis-solamin (4b), non-adjacent bis-THF acetogenin, 4-deoxygigantecin (5), and epoxide-bearing acetogenin, (15S, 16R, 19S, 20R)-diepomuricanin (6a).  相似文献   

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.
A collection of 4-(4-morpholinophenyl)-6-aryl-6H-1,3-thiazin-2-amines (20–28) were synthesized and their in vitro antimicrobial activity was investigated. Compound 21 against P. aeruginosa, 23 against B. subtilis, 24 against V. cholerae and P. aeruginosa, 26 against S. aureus and B. subtilis, 27 against B. subtilis and E. coli, and 28 against all tested bacterial strains exerted excellent antibacterial activity. Compound 20 against A. flavus and Rhizopus, 21, 26 against Rhizopus, 22, 27 against Mucor, 23 against A. flavus, 24 against both A. flavus and Mucor, 25 against all tested strains, and 28 against Rhizopus and M. gypseum exerted excellent antifungal activity.  相似文献   

4.
The enantioselective hydrolysis of (R,S)-3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4H-[1,4]benzoxazine (I) with enzymes was investigated. Optically active I and its hydrolyzate, 7,8-difluoro-2,3-dihydro-3-hydroxymethyl-4H-[1,4]benzoxazine (II), are the intermediates for preparing optically active ofloxacins, whose racemate is known to be an excellent antibacterial agent. Lipoprotein lipase from Pseudomonas fluorescens (LPL Amano 3) was found to predominantly hydrolyze (S)-I, giving (R)-I in 54% e.e. and (R)-II in 44% e.e. On the other hand, lipase from Candida cylindracea was found to predominantly hydrolyze (R)-I, giving (S)-I in 24% e.e. and (S)-II in 20% e.e. Since, the optical purities of I and II thus obtained were not particularly high, these optically active I and II were converted into 3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4-(3,5-dinitrobenzoyl)-4H-[1,4]benzoxazine (IV). After recrystallizing IV from ethyl acetate-hexane, (S)- and (R)-II were obtained with high enantiomeric excess by removing the crystallized racemic IV and subsequently hydrolyzing the resulting optically active IV with alkali. The reduction of II afforded 7,8-difluoro-2,3-dihydro-3-methyl-4H-[1,4]benzoxazine (III), for which the optical purity was estimated to be >96%e.e. by HPLC analysis. (R)- and (S)-ofloxacin were prepared from (R)- and (S)-III with retention of their configuration.  相似文献   

5.
Optically active tiraras-cycloheximide isomers such as cycloheximide [(2S,4S,6RR)-form (1)], naramycin B[(25,4S,6RαR)-form(4)], and new stereoisomers (2S,4S,6SS)-form (8) and (2S,4S,6RS)-from (9) were synthesized by an aldol condensation of trans-2,4-dimethyl-l-cyclohexanone (5b), with 4-(2-oxoethyl)-2,6-piperidinedione(6). The antimicrobial activity of trans- cycloheximide isomers (1, 4, 8, and 9) was examined against S. cerevisiae and P. oryzae. The stereoisomers 1 and 4 exhibited marked antimicrobial activity against both microorganisms as compared with their C- α-epimers 8 and 9.  相似文献   

6.
A revision of the New Caledonian genus Paronthobium Paulian 1984 is presented. Anonthobium Paulian 1984 is synonymized with Paronthobium Paulian 1984 after evaluating the diagnostic characters originally introduced by Paulian to separate them. Upon examination of the type specimens, Onthobium caledonicum Paulian 1935 is separated from O. simplex Fauvel 1903 and restored as valid. Anonthobium moui Paulian 1984 is synonymized with Anonthobium micros Paulian 1984. Fifteen new species are described: P. adio n. sp., P. daghfousi n. sp., P. dierkensi n. sp., P. farino n. sp., P. iac n. sp., P. julieni n. sp., P. memaoya n. sp., P. minutum n. sp., P. nasutum n. sp., P. orientale n. sp., P. peckorum n. sp., P. petchecara n. sp., P. subdentatum n. sp., P. taom n. sp. and P. tchingou n. sp. The genus Paronthobium is now composed of 22 species. Illustrations of parameres and of male protibiae are provided for each species. Distribution maps and a key to species are given.  相似文献   

7.
目的 了解乡镇卫生院各项收支及药品补偿状况,探讨基本药物制度实施后,取消药品加成对乡镇卫生院的影响。方法 收集华东三省49家乡镇卫生院财务及药品收支数据,对定量资料进行统计分析。结果 乡镇卫生院主要的补偿渠道依然是药品收入,乡镇卫生院收入增长主要归因于增加药品收入。在财政补助收入大幅增加的情况下,乡镇卫生院对药品收入的依赖程度有所降低。结论 基本药物制度的实施对乡镇卫生院的平稳运行有影响,可采取加强财政补助、建立综合补偿机制、遏制药品价格虚高等措施保证乡镇卫生院在改革中的平稳运行。  相似文献   

8.
为了研究领春木(Euptelea pleiospermum Hook.f.et Thoms)的化学成分,利用各种柱色谱及高压液相色谱等方法进行分离和纯化,根据理化性质和光谱数据分析鉴定了9个化合物。他们分别为:白桦脂酸(1);齐墩果酸(2);N-反式对羟基肉桂酰基-对羟基苯乙胺(3);N-反式阿魏酰酪胺(4);N-顺式阿魏酰酪胺(5);丁香脂素(6);N-顺式阿魏酰-3-甲氧基酪胺(7);N-反式阿魏酰-3-甲氧基酪胺(8);3-羟基-30-去甲基-20-酮基-28-羽扇豆酸(9)。所有化合物均为首次从领春木中分离得到。  相似文献   

9.
The Japanese Clusiidae are revised and 23 species, including 12 species new to science, are recognized and keyed. Clusiodes angulosus n. sp., Clusiodes discostylus n. sp., Clusiodes tobi n. sp., Clusiodes usikumuri n. sp., Craspedochaeta varicolor n. sp., Heteromeringia crenulata n. sp., Heteromeringia quadrispinosa n. sp., Heteromeringia sexramifera n. sp., Heteromeringia yamata n. sp., Phylloclusia quadrivittata n. sp., Sobarocephala uncinata n. sp., and Tetrameringia borealis n. sp. were described as new. Distribution records were compiled and mapped. Transitional climatic zone between the warm and cool temperate zones is possibly suggested as one of the most richest temperate area in terms of Japanese clusiid species richness. Hendelia beckeri Czerny 1903, Paraclusia japonica Sasakawa 1957, and Clusiodes plumosus Sasakawa 1964 are broadly distributed over all the Japanese temperate forests, but these are not always most abundant species. The clusiid assemblage was heterogeneous in the species composition among various forest types. The femalebiased sample caught by Malaise traps and distinction of clusiid species composition between temperate and subtropical zones are also pointed out.  相似文献   

10.
11.
The three oligosaccharide octyl-S-glycosides Man-α1,6-Man-α1,4-GlcNH2-α1,S-Octyl (19), Man-α1,6-(Gal-α1,3)Man-α1,4-GlcNH2-α1,S-Octyl (27) and Man-α1,2-Man-α1,6-(Gal-α1,3)Man-α1,4-GlcNH2-α1,S-Octyl (37), related to the GPI anchor of Trypanosoma brucei were prepared by a stepwise and block-wise approach from octyl 2-azido-2-deoxy-3,6-di-O-benzyl-1-thio-α-d-glucopyranoside (8) and octyl 2-O-benzoyl-4,6-O-(1,1,3,3-tetraisopropyl-1,3-disiloxane-1,3-diyl)-1-thio-α-d-mannopyransoside (9). Glucosamine derivative 8 was obtained from 1,3,4,6-tetra-O-acetyl-2-azido-2-desoxy-β-d-glucopyranose (1) in five steps. Mannoside 9 was converted into the corresponding imidate 12 and coupled with 8 to give disaccharide octyl-S-glycoside 13 which was further mannosylated to afford trisaccharide 19 upon deprotection. Likewise, mannoside 9 was galactosylated, converted into the corresponding imidate and coupled with 8 to give trisaccharide 25. Mannosylation of the latter afforded tetrasaccharide 27 upon deprotection. Condensation of 25 with disaccharide imidate 35 gave, upon deprotection of the intermediates, the corresponding pentasaccharide octyl-S-glycoside 37. Saccharides 19, 27 and 37 are suitable substrates for studying the enzymatic glycosylation pattern of the GPI anchor of T. brucei.  相似文献   

12.
A summary is presented of all Peruvian species of scaly tree ferns (Cyatheaceae). A total of 83 species is native to Peru (Sphaeropteris 1 sp., Alsophila sect. Alsophila 9 spp., Alsophila sect. Gymnosphaera 1 sp., Cyathea 72 spp.), with 13 endemic species in Cyathea and one in Alsophila. The following new species are described and illustrated: Alsophila gastonyi, Cyathea chontilla, C. nephele, C. polliculi, and C. praetermissa. The genera Cnemidaria and Trichipteris are no longer recognized and merged in Cyathea. Necessary combinations are made for Cyathea alatissima, C. nervosa, and C. uleana. Cyathea serpens is presented in detail and its relationship is discussed. An artificial key to the Peruvian species of Cyatheaceae is provided.  相似文献   

13.
Lithospermum (Boraginaceae) comprises approximately 40 species in both the Old and New Worlds, with a center of diversity in the southwestern United States and Mexico. Using ten cpDNA regions, a phylogeny of Lithospermum and related taxa was reconstructed. Lithospermum (including New World and Old World species) and related New World members of Lithospermeae form a monophyletic group, with Macromeria, Onosmodium, Nomosa, Lasiarrhenum, and Psilolaemus nested among species of Lithospermum. New World Lithospermeae also is a monophyletic group, with Eurasian species of Lithospermum sister to this group. Because Lithospermum is not monophyletic without the inclusion of the other New World genera, species from these genera are transferred to Lithospermum, and appropriate nomenclatural changes are made. New combinations are Lithospermum album, Lithospermum barbigerum, Lithospermum dodrantale, Lithospermum exsertum, Lithospermum helleri, Lithospemum leonotis, Lithospermum notatum, Lithospermum oaxacanum, Lithospermum pinetorum, Lithospermum rosei, Lithospermum trinverium, and Lithospermum unicum; new names are Lithospermum chiapense, Lithospermum johnstonii, Lithospermum macromeria, Lithospermum onosmodium, Lithospermum rzedowskii, and Lithospermum turneri.  相似文献   

14.
Abstract

Reaction of 2′,3′,5′-O-silylated inosine derivative 1 with 2, 3-O-isopropylidene-5-O-tritylribosyl chloride (3) in a two-phase (CH2Cl2-aq. NaOH) system in the presence of Bu4NBr gave three products, i. e., 6-O-α-, 6-O-β-, and N 1-β-isomers of glycosides 4, 5a, and 5b. A similar PTC reaction of 1 with 2, 3, 5-tri-O-benzylribosyl bromide (9) gave four regio- and stereo-isomers involving the N1-β-glycoside 10. Reaction of 1 with 2, 3, 5-tri-O-benzoylribosyl bromide (11) afforded three products involving the desired N1-β-glycoside 12b, which could be deprotected to give N 1-ribosylinosine (15b) as a useful intermediate for the synthesis of cIDPR.

  相似文献   

15.
Asymmetric hydrolysis of acetate (10) of (±)-t-2,t-4-dimethyl-r-l-cyclohexanol with Bacillus subtilis var. niger gave (?)-(lS,2S,4S)-2,4-dimethyl-l-cyclohexanol (6a) and (+)-(1R,2R,4R)-acetate (10b) with high optical purities. Optically pure (?) and (+)-alcohols (6a and 6b) were prepared via corresponding 3,5-dinitrobenzoates. Oxidation of alcohols (6a and 6b) with chromic acid gave optically pure (?)-(2S,4S) and (+)-(2R,4R)-2,4-dimethyl-l-cyclohexanones (2a and 2b), respectively.  相似文献   

16.
Summary. The Adoretini of the Malagasy endemic genus Adorodocia Brenske 1893 is revised. Fourteen new species and one new subspecies are described and compared with their most closely related species: A. constricta n. sp., A. cuccodoroi n. sp., A. flava n. sp., A. liliae n. sp., A. marginata n. sp., A. peyrierasi n. sp., A. pseudoconstricta n. sp., A. pseudoflava n. sp., A. pseudostrigata n. sp., A. recta n. sp., A. robusta n. sp., A. sogai n. sp., A. vadoni n. sp., A. viettei n. sp. and A. vittaticollis flavipes n. ssp. The synonymy between Adoretus strigatus Waterhouse 1878, and Pseudadorodocia aenigma Arrow 1901, is confirmed. Thus, based on the results of this study, the genus Adorodocia includes 16 species, and one of them is represented by two subspecies. Diagnostic characters to separate the species in the genus deal mostly with the shape of parameres, color of body and legs, shape of pronotum and female eighth tergite, setation of pronotum and elytra. Key to species, diagnoses and distribution for each species are provided. Endophallus and female genitalia are illustrated for the first time for this genus.  相似文献   

17.
Summary rac-2-Acetoxy-1,1-dimethyl-1-sila-cyclohexane (rac-2) was synthesized by esterification of rac-1,1-dimethyl-1-sila-cyclohexan-2-ol (rac-1) with acetic anhydride. Enantioselective hydrolysis of rac-2 in aqueous solution, catalysed by a crude lipase preparation of Candida cylindracea (EC 3.1.1.3), led to the formation of (S)-1 (95% ee). Enantioselective transesterification of rac-1 with triacetin in isooctane, catalysed by the same enzyme preparation, yielded (S)-2 (95% ee), which was separated by chromatography from non-reacted (R)-1 (96% ee). Recrystallization led to an improvement of the enantiomeric purity of (R)-1 and (S)-1 up to >98% ee. Thus the enantiomers of rac-1 were prepared (100 mg scale) with high enantiomeric purities by the use of two different types of enzyme-catalysed reaction.  相似文献   

18.
The species belonging to Tychus rufus group are revised. Eleven species are recognized, described and illustrated and a key to their identification is provided. Nine taxa are new to science: Tychus carpathius n. sp. from Karpathos island (Greece); T. torticornis n. sp. from Lesbos Island (Greece); T. pisidicus n. sp. and T. inermis n. sp. from southwestern Turkey; T. antiocheus n. sp. and T. effeminatus n. sp. from southeastern Turkey; T. artvinensis n. sp. from northeastern Turkey, and T. sidonicus n. sp. and T. libanus n. sp. from Lebanon.  相似文献   

19.
The species Anomala aereiventris n. sp., A. aspersa n. sp., A. atrivillosa n. sp., A. clarivillosa n. sp., A. contusa n. sp., A. eusticta n. sp., A. hiata n. sp., A. latifalculata n. sp., A. leopardina n. sp., A. levicollis n. sp., A. longisacculata n. sp., A. m-fuscum n. sp., A. perspicax n. sp., A. piccolina n. sp., A. globulata n. sp., A. stillaticia n. sp., A. subridens n. sp., A. subusta n. sp., A. tenoriensis n. sp., A. tuberculata n. sp. and A. vallisneria n. sp. from Costa Rica are described. These species and A. polygona Bates 1888, A. trapezifera Bates 1888 and A. vulcanicola Ohaus 1897 are placed in a new species-group, named after A. trapezifera, whose diagnosis is provided. Their distribution patterns are discussed.  相似文献   

20.
【背景】武夷菌素高产基因工程菌株Streptomyce albulus OoWysR具有明显的抑菌效果。【目的】明确S.albulus OoWysR的活性成分。【方法】采用柱层析法,利用大孔吸附树脂、离子交换树脂和高效液相色谱等对S.albulus OoWysR的活性成分进行分离纯化,经高分辨率电喷雾电离质谱(high-resolution electrospray ionization mass spectrometry,HR-ESI-MS)和核磁共振(nuclear magnetic resonance,NMR)等波谱技术对化合物化学结构进行鉴定,并通过生长速率法测定化合物的生物活性。【结果】从S.albulus OoWysR中分离鉴定出4个化合物,分别为对羟基苯甲酸(1)、吡咯-2-羧酸(2)、对羟基苯乙醇(3)和云南霉素(4)。化合物1对玉米弯孢病菌、番茄叶霉病菌、玉米小斑病菌和烟草赤星病菌具有一定的抑制作用;化合物2对番茄灰霉病菌、大豆菌核病菌、苹果腐烂病菌、玉米小斑病菌、小麦赤霉病菌、稻瘟病菌和烟草赤星病菌具有一定的抑制作用;化合物3对番茄灰霉病菌、苹果轮纹病菌、玉米小斑病...  相似文献   

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