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991.
Bioactive monoterpene glycosides conjugated with gallic acid from the leaves of Eucalyptus globulus 总被引:2,自引:0,他引:2
Two monoterpene glycosides, conjugated with gallic acid [globulusin A (1) and B (2)], together with four known compounds, cypellocarpin A (3), eucaglobulin (4), cuniloside (5) and (1S, 2S, 4R)-trans-2-hydroxy-1,8-cineole beta-d-glucopyranoside (6), were isolated from hot-water extracts of the leaves of Eucalyptus globulus. The structures of compounds 1 and 2 were determined by 1D, 2D NMR and MS spectroscopic analyses. The absolute stereochemistry of 1 was determined by correlating the spectroscopic data with those of synthetic compound 6 with a known configuration. Globulusin A (1) and B (2), cypellocarpin A (3) and eucaglobulin (4), scavenged DPPH free radicals and globulusin A (1) showed a higher antioxidant activity than the other tested compounds, with an IC50 of 3.8microM. Globulusin A (1) and eucaglobulin (4) concentration-dependently suppressed inflammatory cytokine production, tumor-necrosis factor-alpha and interleukin-1beta in cultured human myeloma THP-1 cells co-stimulated with phorbol myristate acetate. These compounds also inhibited melanogenesis in cultured murine melanoma B16F1 cells, without any significant cytotoxicity. These results suggested that globulusin A (1) and eucaglobulin (4), which were isolated as antioxidants from E. globulus, also had anti-inflammatory as well as anti-melanogenesis activity. 相似文献
992.
When Shigella infect the intestinal epithelium, they deliver several effectors through the type III secretion system (T3SS) into the surrounding space and directly into the host-cell cytoplasm, where they can mimic and usurp host cellular functions or subvert host-cell signalling pathways and the immune response. Although bacterial strategies and mechanisms of infection vary greatly, recent studies of Shigella effectors have revealed that Shigella possess a highly evolved strategy for infection. 相似文献
993.
The phylogenetic positioning of the non-pathogenic genusSpiromastix in the Onygenales was studied based on large subunit rDNA (LSU rDNA) partial sequences (ca. 570 bp.). FourSpiromastix species and 28 representative taxa of the Onygenales were newly sequenced. Phylogenetic trees were constructed by the neighbor-joining
(NJ) method and evaluated by the maximum parsimony (MP) method with the data of 13 taxa retrieved from DNA databases.Spiromastix and dimorphic systemic pathogens,Ajellomyces andParacoccidioides, appear to be a monophyletic group with 74% bootstrap probability (BP) in the NJ tree constructed with the representative
taxa of the Onygenales. The tree topology was concordant with the NJ tree based on SSU rDNA sequences of our previous work
and corresponded to the classification system of the Onygenales by Currah (1985) and its minor modification by Udagawa (1997)
with the exception of the classification of the Onygenaceae. The Onygeneceae sensu Udagawa may still be polyphyletic, since
three independent lineages were recognized. The taxa forming helicoid peridial appendages were localized to two clades on
the tree. The topology of the NJ tree constructed withSpiromastix and its close relatives suggested that the helicoid peridial appendages were apomorphic and acquired independently in the
two clades of the Onygenales. 相似文献
994.
Wataru Morita Naoki Morimoto Yutaka Kunimatsu Arnaud Mazurier Clément Zanolli Masato Nakatsukasa 《Comptes Rendus Palevol》2017,16(5-6):655-669
Clarifying morphological variation among African and Eurasian hominoids during the Miocene is of particular importance for inferring the evolutionary history of humans and great apes. Among Miocene hominoids, Nakalipithecus and Ouranopithecus play an important role because of their similar dates on different continents. Here, we quantify the lower fourth deciduous premolar (dp4) inner morphology of extant and extinct hominoids using a method of morphometric mapping and examine the phylogenetic relationships between these two fossil taxa. Our data indicate that early Late Miocene apes represent a primitive state in general, whereas modern great apes and humans represent derived states. While Nakalipithecus and Ouranopithecus show similarity in dp4 morphology to a certain degree, the dp4 of Nakalipithecus retains primitive features and that of Ouranopithecus exhibits derived features. Phenotypic continuity among African ape fossils from Miocene to Plio-Pleistocene would support the African origin of African apes and humans (AAH). The results also suggest that Nakalipithecus could have belonged to a lineage from which the lineage of Ouranopithecus and the common ancestor of AAH subsequently derived. 相似文献
995.
Yuki Nagaya Yoshiaki Kitamura Aya Shibata Masato Ikeda Yukihiro Akao Yukio Kitade 《Bioorganic & medicinal chemistry letters》2017,27(24):5454-5456
Chemically modified siRNAs containing 2-O-benzyl-1-deoxy-d-ribofuranose (RHOBn) in their 3′-overhang region were significantly more resistant towards serum nucleases than siRNAs possessing the natural nucleoside in this region. The knockdown efficacies and binding affinities of these modified siRNAs to the recombinant human Argonaute protein 2 (hAgo2) PAZ domain were comparable with that of siRNA with a thymidine dimer at the 3′-end. 相似文献
996.
E-Cadherin is an intercellular adhesion molecule that regulates cell functions such as differentiation and proliferation of cells. To clarify the potential of E-cadherin-mediated adhesion to induce differentiation, we constructed an adsorbable recombinant E-cadherin molecule by fusing with an immunoglobulin G (IgG) Fc region (E-cad-Fc). Hepatocytes could adhere to the fusion protein-coated surface by a homophilic interaction of E-cadherins and showed differentiated phenotypes such as low DNA synthesizing activity and maintenance of tryptophan oxygenase expression, similar to those of spheroid-formed hepatocytes that are known as a highly differentiated tissue-like cell aggregation. These results suggest that E-cadherin is a key molecule for maintaining differentiation of primary hepatocytes. 相似文献
997.
Shingo Tamura Toshinori Bito Masamitsu Ichihashi Masato Ueda 《Pigment cell & melanoma research》2003,16(5):470-476
Genistein, a naturally occurring isoflavone found chiefly in soybeans, has been reported to be a potent antitumor agent. Genistein is presumed to exert multiple effects related to the inhibition of cancer growth. Metastatic melanoma is a chemotherapy‐refractory neoplasm. The present study was designed to explore the possible activity of genistein to inhibit the aberrant proliferation and to induce apoptosis of human malignant melanoma cells in cooperation with cisplatin treatment. Five human melanoma cell lines were utilized for these experiments. Genistein at physiologic concentrations (20 μM) did not induce apoptosis by itself but did enhance cisplatin‐induced apoptosis in all five human melanoma cell lines tested. The enhanced susceptibility among the cell lines was diverse. Changes in the expression of two anti‐apoptotic proteins, bcl‐2 and bcl‐xL, and one pro‐apoptotic protein, apoptotic protease activating factor‐1 (Apaf‐1), were examined. Genistein alone or cisplatin alone generally did not alter bcl‐2 expression or bcl‐xL expression, but slightly increased Apaf‐1 in some cell lines. The combined treatment with genistein and cisplatin significantly reduced bcl‐2 and bcl‐xL protein and increased Apaf‐1 protein expression. These data suggest that genistein therapy may enhance the chemosensitivity of melanoma patients. 相似文献
998.
999.
Chun-Hong Qiu Masato Ohe Noriyuki Koibuchi Shigeru Matsuzaki 《The journal of histochemistry and cytochemistry》2004,52(2):187-192
Apoptosis in the testis and prostate exposed to disrupters of endocrine function, including diethylstilbestrol (DES), during neonatal or postnatal periods has repeatedly been demonstrated, but not in the mature epididymis. We investigated the effects of DES, a potent and synthetic estrogen, on apoptosis in the adult. Adult male golden hamsters received an SC injection of DES and were then sacrificed to collect epididymides after 1, 4, or 7 days of treatment. A significant decrease in epididymal weight and an increase in apoptotic cells were shown on the first day after DES injection. Flow cytometry showed that DES treatment (1 mg/kg) for 1, 4, or 7 days induced significant apoptosis both in the caput and the cauda epididymides. Greater numbers of apoptotic cells were detected in the caput than in the cauda at a fixed time after DES treatment. Serum levels of testosterone decreased markedly within 24 hr after DES administration, reaching undetectable levels of 0.1 ng/ml at 4 days and thereafter. These results indicate that DES administration can increase epididymal apoptosis with a decrease in serum testosterone levels. Because DES used to be injected into domestic animals, adult males also have a chance to take this substance through food. Our study indicates that exposure to DES in adults is as toxic as that in the perinatal period. 相似文献
1000.
There is a region exhibiting a similarity of amino acid sequence near the carboxyl-terminal segment of each FAD-containing
oxidoreductase. In this region, four amino acid residues—Thr, Ala, Gly, and Asp—are highly conserved. To determine the involvement
of the four amino acid residues (Thr-469, Ala-476, Gly-478, and Asp-479) in the activity of NADH dehydrogenase of an alkaliphilic
Bacillus, mutations of these amino acid residues were conducted. In spite of high conservation, mutations of Thr-469 and Ala-476 to
Ala and Ser, respectively, did not lead to a critical loss of enzyme activity. However, mutations of Gly-478 and Asp-479 to
Ala caused a complete loss of the activity, which appears to result from the loss of binding capacity of FAD.
Received: 3 July 2002 / Accepted: 29 July 2002 相似文献