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1.
A new epidithiodioxopiperazine derivative, emethallicin A (1), was isolated along with ergosterol from the mycelial extract of the heterothallic fungus, Emericella heterothallica (mating type A). The structure of emethallicin A (1) was established on the basis of chemical and spectroscopic investigations and finally by chemical transformation to apoaranotin (11). Emethallicin A (1) has the same basic skeleton as apoaranotin (11), with C6-C2 carboxylic acid (mandelic and phenylacetic acids) diester moieties, and showed a potent inhibitory activity on histamine release from mast cells. 相似文献
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Lee SH Kim HK Seo JM Kang HM Kim JH Son KH Lee H Kwon BM Shin J Seo Y 《The Journal of organic chemistry》2002,67(22):7670-7675
Arteminolides B-D (2-4), new farnesyl protein transferase inhibitors, were isolated together with a known arteminolide A (1) and new regioisomers (5-7) of the compounds from the aerial parts of Artemisia argyi. Structures of these compounds were elucidated by spectroscopic methods and chemical conversion. Arteminolides inhibited the farnesyl protein transferase with IC(50) values of 0.7-1 microM, while the regioisomers 5-7 were inactive. In addition, it was proved that the exocyclic double bond of sesquiterpene lactone did not affect the inhibitory activity of arteminolide. The effects of compound 2 on H-Ras processing and cellular growth in H-ras-transformed cells were also evaluated. 相似文献
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Three new compounds, orirubenone A (1), B (2) and C (3) were isolated from the mushroom Tricholoma orirubens. Their structures were determined by spectral analyses. These compounds inhibited hyaluronan-degradation by human skin fibroblasts. 相似文献
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McDonald LA Barbieri LR Carter GT Lenoy E Lotvin J Petersen PJ Siegel MM Singh G Williamson RT 《Journal of the American Chemical Society》2002,124(35):10260-10261
The muraymycins, a family of nucleoside-lipopeptide antibiotics, were purified from the extract of Streptomyces sp. LL-AA896. The antibiotics were purified by chromatographic methods and characterized by NMR spectroscopy, degradation studies, and mass spectrometry. The structures of 19 compounds were established. The muraymycins constitute a new antibiotic family whose core structure contains a glycosylated uronic acid derivative joined by an aminopropane group to a hexahydro-2-imino-4-pyrimidylglycyl residue (epicapreomycidine) containing dipeptide that is further extended by a urea-valine moiety. Members of this family show broad-spectrum in vitro antimicrobial activity against a variety of clinical isolates (MIC 2 to >64 mug/mL). The muraymycins inhibited peptidoglycan biosynthesis. The fatty acid substituent and the presence or absence of the amino sugar play important roles in biological activity. One of the most active compounds, muraymycin A1, demonstrated protection in vivo against Staphylococcus aureus infection in mice (ED50 1.1 mg/kg). 相似文献
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Masakazu Uramoto Kimie Kobinata Kiyoshi Isono Tsutomu Higashijima Tatsuo Miyazawa E.E. Jenkins James A. McCloskey 《Tetrahedron letters》1980,21(35):3395-3398
The absolute structures of fungal chitin synthetase inhibitors, neopolyoxins A, B, and C were determined as 1, 2, and 3 respectively on the basis of chemical and spectroscopic evidence. 相似文献
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Shinji Funayama Masami Ishibashi Yumi Anraku Kanki Komiyama Satoshi
mura 《Tetrahedron letters》1989,30(52):7427-7430
Structures of novel citocydal antibiotics furaquinocins A and B, isolated from the fermentation broth of Streptomyces sp. KO-3988, was elucidated on the basis of spectroscopic analyses. 相似文献
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Morita H Ishioka N Takatsu H Shinzato T Obara Y Nakahata N Kobayashi J 《Organic letters》2005,7(3):459-462
[structure: see text] Two novel alkaloids with an unprecedented fused-pentacyclic skeleton, daphmanidins C (1) and D (2), have been isolated from the leaves of Daphniphyllum teijsmanii, and the structures were elucidated on the basis of spectroscopic data. The relative stereochemistry of 1 and 2 was assigned by combination of NOESY correlations and a simulation analysis. Daphmanidin C (1) elevated activity of NGF biosynthesis. 相似文献
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Y Ikeda M Sugiura C Fukaya K Yokoyama Y Hashimoto K Kawanishi M Moriyasu 《Chemical & pharmaceutical bulletin》1991,39(3):566-571
During the course of our screening of bioactive natural products, three new saponins named periandradulcins A (1), B (2) and C (3) were isolated as phosphodiesterase (PDE, EC 3.1.4.17) inhibitors from 80% MeOH extract of the roots of Periandra dulcis Mart. (Leguminosae) by a combination of column chromatography and reversed- and normal-phase high-performance liquid chromatography (HPLC). On the basis of 1H-, 13C- and two-dimensional nuclear magnetic resonance (NMR) spectral data and chemical evidence, their chemical structures were characterized as 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D-xylopyranosyl(1----2)-b eta-D- glucuronopyranosyl]-30-hydroxyl-25-formylolean-18-ene-22 beta-O-syringate, 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- xylopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25- formylolean-12-ene and 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- glucopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25-formylolean-18-ene, respectively. The concentrations of periandradulcins A, B and C required to give 50% inhibition (IC50 values) of PDE from bovine heart, were 0.033, 7.6 and 7.7 microM, respectively. Compound 1 was the most potent among the known PDE inhibitors; it inhibited PDE-I (IC50:0.0022 microM) twenty and forty times more effectively than PDE-II and -III, respectively. 相似文献
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《中国化学快报》2023,34(2):107529
Heat shock protein 90 (Hsp90) is an appealing anticancer drug target that provoked a tremendous wave of investigations. Geldanamycin (GA) is the first identified Hsp90 inhibitor that exhibited potent anti-cancer activity, but the off-target toxicity associated with the benzoquinone moiety hampered its clinical application. Until now, structure optimization of GA is still in need to fully exploit the therapeutic value of Hsp90. Due to the structural complexity and synthetic challenge of this compound family, conventional optimization is bound to be costly but high efficiency is expected to be reachable by combining the art of rational design and total synthesis. Described in this paper is our first attempt at this approach aiming at rational modification of the C6-position of GA. The binding affinities towards Hsp90 of compound 1 (C6-ethyl) and 2 (C6-methyl) were designed and predicted by using Discovery Studio. These compounds were synthesized and further subjected to a thorough in vitro biological evaluation. We found that compounds 1 and 2 bind to Hsp90 protein with the IC50 of 34.26 nmol/L and 163.7 nmol/L, respectively. Both compounds showed broad-spectrum antitumor effects. Replacing by ethyl, compound 1 exhibited more potent bioactivity than positive control GA, such as in G2/M cell cycle arrest, cell apoptosis and client proteins degradations. The results firstly indicated that the docking study is able to provide a precise prediction of Hsp90 affinities of GA analogues, and the C6 substituent of GA is not erasable without affecting its biological activity. 相似文献
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Takeshi Yamada Takashi Kikuchi Reiko Tanaka Atsushi Numata 《Tetrahedron letters》2012,53(23):2842-2846
Halichoblelide B (1) and C (2), novel macrolides with potent cytotoxicity against tumor cells in culture, have been isolated from a strain of Streptomyces hygroscopicus originally derived from the marine fish Halichoeres bleekeri, and their absolute stereostructures have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and chemical transformations. These compounds exhibited significant cytotoxicity against human cancer cell lines. 相似文献
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[structure: see text] The relative and absolute stereochemistry of the structurally unique 24-membered myxobacterial macrolides archazolid A and B, highly potent vacuolar-type ATPase (V-ATPase) inhibitors in vitro and in vivo, was determined on the basis of a combination of extensive high-field NMR studies, including J-based configuration analysis, molecular modeling, and chemical methods. 相似文献
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Five new polyacetylene glucosides, bidensyneosides A1, A2, B, C (1-4), and 3-deoxybidensyneoside B (5), have been isolated from the air-dried whole plant of Bidens parviflora WILLD. The structures were identified based on spectroscopic analysis, physicochemical properties, and application of the modified Mosher method to be 3(R),8(E)-8-decene-4,6-diyne-1,3-diol 1-O-beta-D-glucopyranoside (1), deca-3(R),8(Z) 8-decene-4,6-diyne-1,3-diol 1-O-beta-D-glucopyranoside (2), 3(R)-deca-4,6,8-triyne-1,3-diol 1-O-beta-D-glucopyranoside (3), 3(R),8(E)-8-decene-4,6-diyne-1,3,10-triol 1-O-beta-D-glucopyranoside (4), and 8(E)-8-decene-4,6-diyne-1,10-diol 1-O-beta-D-glucopyranoside (5), respectively. These compounds inhibited nitric oxide (NO) production in lipopolysaccharide and interferon-gamma activated murine macrophages (RAW264.7) and also inhibited histamine release from rat mast cells stimulated by the antigen-antibody reaction. 相似文献
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Isolation and structure elucidation of three peptide antibiotics, discodermins B, C, and D, from the marine sponge, Discodermia kiiensis, and the revised structure of discodermin A are described. 相似文献
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S. A. Shvets A. M. Naibi P. K. Kintya A. S. Shashkov 《Chemistry of Natural Compounds》1995,30(3):328-331
Oplodiol, 3-hydroxyepimanool, and epitorulosol have been isolated for the first time from the oleoresin ofPicea ajanensis. On the basis of the results obtained, it may be assumed that the species studied is possibly a hybrid of Yeddo spruce and Siberian spruce.Novosibirsk Institute of Organic Chemistry, Siberian Division of the Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 359–363, May–June, 1994. 相似文献
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K Nozawa Y Horie S Udagawa K Kawai M Yamazaki 《Chemical & pharmaceutical bulletin》1989,37(5):1387-1389
The distribution of a tremorgenic mycotoxin, paxilline (1), was investigated in 19 species belonging to the genus Emericella. It was found that Emericella desertorum, E. foveolata, and E. striata produced paxilline (1). A new type of indoloditerpene, emindole DA (4), was also found in E. quadrilineata. A new tremorgenic indoloditerpene, 1'-O-acetylpaxilline (3), was isolated from the mycelium of E. striata. Its structure was established on the basis of spectroscopic investigations. 相似文献
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BACKGROUND: NADH:ubiquinone oxidoreductase (complex I) is the first of three large enzyme complexes located in the cell's inner mitochondrial membrane which form the electron transport chain that carries electrons from NADH to molecular oxygen during oxidative phosphorylation. There is significant interest in developing small molecule inhibitors of this enzyme for use as biological probes, insecticides and potential chemopreventive/chemotherapeutic agents. Herein we describe the application of novel natural product-like libraries to the discovery of a family of potent benzopyran-based inhibitors. RESULTS: Initially a combinatorial library of benzopyrans, modeled after natural products, was synthesized using a solid phase cycloloading strategy. Screening of this diversity oriented library for inhibitory potency against NADH:ubiquinone oxidoreductase activity in vitro using bovine heart electron transport particles provided several lead compounds which were further refined through a series of focused libraries. CONCLUSIONS: Using this combinatorial library approach, a family of potent 2,2-dimethylbenzopyran-based inhibitors was developed with IC(50) values in the range of 18-55 nM. Cell-based assays revealed that these inhibitors were rather non-cytotoxic in the MCF-7 cell line; however, they were quite cytostatic in a panel of cancer cell lines suggesting their potential as chemotherapeutic/chemopreventive candidates. 相似文献