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5. Involvement of brain oxidation in the cognitive impairment in a triple transgenic mouse model of Alzheimer's disease: Noninvasive measurement of the brain redox state by magnetic resonance imaging

Author

Ishihara, Y., primary, Itoh, K., additional, Mitsuda, Y., additional, Shimada, T., additional, Kubota, T., additional, Kato, C., additional, Song, S. Y., additional, Kobayashi, Y., additional, Mori-Yasumoto, K., additional, Sekita, S., additional, Kirino, Y., additional, Yamazaki, T., additional, and Shimamoto, N., additional

Published
2013
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14. Cytotoxicity of new cytochalasans from Chaetomium globosum.

Author

Umeda, M., Ohtsubo, K., Saito, M., Sekita, S., Yoshihira, K., Natori, S., Udagawa, S., Sakabe, F., and Kurata, H.

Abstract

Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
1975
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15. Dammarane-Type Triterpenes from the Brazilian Medicinal Plant Cordia multispicata

Author

Kuroyanagi, M., Kawahara, N., Sekita, S., Satake, M., Hayashi, T., Takase, Y., and Masuda, K.

Abstract

From the Brazilian medicinal plant Carucaá (Cordia multispicata), oleanane- and ursane-type triterpenoids were previously reported as anti-androgenic constituents of the plant. In this study, purification of the polar elements of the EtOAc-soluble fraction of the plant revealed nine novel dammarane-type triterpenes, named cordianols A−I (1−9) along with the known compound cordialin A (10). The structures of these new compounds were elucidated by means of spectral methods including HRFABMS, 1H NMR, 13C NMR, and 2D NMR (HMQC, HMBC, NOESY). Absolute configuration at C-23 of compound 7 was determined by an excitone chirality method. Some of these new compounds revealed a hemiketal structure on the A ring and a hydroxylated or epoxidated 20(22)-(E)-ene side chain and showed weak anti-androgenic activity.

Published
2003

16. Phenolic Constituents from Dalbergia cochinchinensis

Author

Shirota, O., Pathak, V., Sekita, S., Satake, M., Nagashima, Y., Hirayama, Y., Hakamata, Y., and Hayashi, T.

Abstract

Three new phenolic compounds (1−3), along with five known phenolics, 4‘-hydroxy-2‘-methoxychalcone (4), latinone (5), dalbergiphenol (6), 7-hydroxyflavanone, and dalbergin (7), have been isolated from the stems of Dalbergia cochinchinensis. The structures of 1−3 were established by spectroscopic techniques including 1D and 2D NMR methods. The inhibitory activity against testosterone 5α-reductase, which causes androgen-dependent diseases, was also examined for selected compounds.

Published
2003

17. New Phenolic Constituents from Smilax bracteata

Author

Li, S. Y., Fuchino, H., Kawahara, N., Sekita, S., and Satake, M.

Abstract

From the methanol extract of Smilax bracteata rhizomes, six new phenolic compounds, (2S,3S)-5-O-β-d-glucopyranosyloxy-6-methyl-3‘-methoxy-3,7,3‘-trihydroxyflavan (1), (2S,3S)-5-O-β-d-glucopyranosyloxy-6-methyl-4‘-methoxy-3,7,4‘-trihydroxyflavan (2), 3β-(3‘,5‘-dihydroxyphenyl)-2α-(4‘ ‘-hydroxyphenyl)dihydrobenzofuran-5-carbaldehyde (3), (1-p-O-coumaroyl-6-O-feruroyl)-β-d-fructofuranosyl-α-d-glucopyranoside (4), (1-p-O-coumaroyl-3,6-di-O-feruroyl)-β-d-fructofuranosyl-α-d-glucopyranoside (5), and (6-O-feruroyl)-β-d-fructofuranosyl-(6-O-acetyl)-α-d-glucopyranoside (6) were isolated together with five known compounds. Their structures were established by spectral data interpretation.

Published
2002
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20. Antiandrogenic Natural Diels−Alder-Type Adducts from Brosimum rubescens

Author

Shirota, O., Takizawa, K., Sekita, S., Satake, M., Hirayama, Y., Hakamata, Y., Hayashi, T., and Yanagawa, T.

Abstract

The isolation and structure elucidation of five novel natural Diels−Alder-type adducts, named palodesangrens A−E (1−5), from the Peruvian folk medicine known as “palo de sangre” (Brosimum rubescens) is described. The structures of the Diels−Alder adducts, consisting of chalcone derivatives and a prenylcoumarin, were elucidated by analysis of spectroscopic data including 2D NMR. Some of these compounds showed potent inhibitory activity towards 5α-dihydrotestosterone (DHT) binding with an androgen receptor to form a DHT-receptor complex that causes androgen-dependent diseases.

Published
1997

21. Correlation between effects of 24 different cytochalasins on cellular structures and cellular events and those on actin in vitro

Author

Yahara, I, Harada, F, Sekita, S, Yoshihira, K, and Natori, S

Abstract

To compare the effects of cytochalasins on the cellular level with those on the molecular level, 24 cytochalasins, 20 natural compounds and 4 derivatives, were used. The following effects were tested for each of 24 cytochalasins; (a) four high dose (2-20 muM) effects on the cellular level: rounding up of fibroblastic cells, contraction of actin cables, formation of hairy filaments containing actin, and inhibition of lymphocyte capping; (b) a low dose (0.2-2 muM) effect: inhibition of membrane ruffling; and (c) two in vitro effects: an inhibition of actin filament elongation (the high affinity effect [low dose effect] in vitro) and an effect on viscosity of actin filaments(the low affinity effect [high dose effect] in vitro). These results indicated that there are almost the same hierarchic orders of relative effectiveness of different cytochalasins between low and high dose effects and between cellular and molecular effects. From the data obtained with the 24 cytochalasins, we have calculated correlation coefficients of 0.87 and 0.79 between an effect in vivo, inhibition of capping, and an effect in vitro, inhibition of actin filament elongation, as well as between inhibition of capping and another effect in vitro, effect on viscosity of actin filaments, respectively. Furthermore, a correlation coefficient between the high affinity effect and the low affinity effect determined in vitro was calculated to be 0.90 from the data obtained in this study. The strong positive correlation among low and high dose effects in vivo and those in vitro suggests that most of the effects caused by a cytochalasin, irrespective of doses or affected phenomena, might be attributed to the interaction between the drug and the common target protein, actin. In the course of the immunofluorescence microscope study on cytochalasin-treated cells using actin antibody, we have found that aspochalasin D, a 10-isopropylcytochalasin, strongly induced the formation of rodlets containing actin in the cytoplasm of the treated fibroblasts. In contrast, the other cytochalasins, including cytochalasin B, cytochalasin C, cytochalasin D, and cytochalasin H, were found to induce the formation of nuclear rodlets. Both cytoplasmic and nuclear rodlets found in the cytochalasin-treated cells were similar in ultrastructures to those induced by 5 to 10 percent (vol/vol) dimethyl sulfoxide in the same type of cells.

Published
1982
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23. Chemical Constituents of Chinese Folk Medicine “Sân Léng”, Sparganium stoloniferum

Author

Shirota, O., Sekita, S., Satake, M., Ni, Y., and Weiyi, H.

Abstract

The isolation and structure elucidation of three phenylpropanoid glycosides (1−3) along with three known phenylpropanoid glycerides from Chinese folk medicine “Sân Léng” (Sparganium stoloniferum Buch.−Hamil.) are described. The structures of these phenylpropanoid glycosides and glycerides were elucidated by a combination of chemical and spectroscopical evidence including 2D-NMR studies.

Published
1996

29. 13C-NMR of chaetoglobosins

Author

SEKITA, S., primary, YOSHIHIRA, K., additional, NATORI, S., additional, UDAGAWA, S., additional, SAKABE, F., additional, and KURATA, H., additional

Published
1982
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38. Mycotoxins

Author

TAKAHASHI, C., primary, SEKITA, S., additional, YOSHIHIRA, K., additional, NATORI, S., additional, UDAGAWA, S., additional, SAKASE, F., additional, KURATA, H., additional, TSUNODA, H., additional, KISHI, K., additional, UENO, Y., additional, OKUBO, K., additional, TSURUTA, O., additional, SUGIMOTO, T., additional, MINAMISAWA, M., additional, YOSHIZAWA, T., additional, TSUCHIYA, Y., additional, TERAURA, M., additional, MOROOKA, N., additional, MATSUMAE, A., additional, TSUDA, Y., additional, HOSHINO, M., additional, NAKASE, Y., additional, LU, Y. S., additional, OHTA, M., additional, YAMAZAKI, M., additional, FUJIMOTO, H., additional, KAWASAKI, T., additional, OSAME, J., additional, MURAKOSHI, S., additional, AKUTSU, S., additional, ICHINOE, M., additional, KUMADA, H., additional, KURODA, M., additional, TANZAWA, K., additional, ENDO, A., additional, SUGAMATA, M., additional, WAJIMA, O., additional, SHINOHARA, Y., additional, HIRAO, K., additional, FUKUSHIMA, S., additional, NAKANISHI, K., additional, and ITO, N., additional

Published
1976
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48. Establishment and characterization of two novel patient-derived cell lines from myxofibrosarcoma: NCC-MFS7-C1 and NCC-MFS8-C1.

Author

Adachi Y, Noguchi R, Osaki J, Ono T, Iwata S, Akiyama T, Tsuchiya R, Toda Y, Tetsuya S, Iwata S, Kobayashi E, Kojima N, Yoshida A, Yokoo H, Kawai A, and Kondo T

Subjects
Humans, Cell Line, Tumor, Doxorubicin pharmacology, Antineoplastic Agents pharmacology, Drug Screening Assays, Antitumor, Neoplasm Invasiveness, Male, Middle Aged, Fibrosarcoma pathology, Fibrosarcoma genetics, Dactinomycin pharmacology, Cell Proliferation, Bortezomib pharmacology, Depsipeptides pharmacology
Abstract

Myxofibrosarcoma (MFS), an aggressive soft tissue sarcoma, presents a significant challenge because of its high recurrence rate, distal metastasis, and complex genetic background. Although surgical resection is the standard treatment for MFS, the outcomes are unsatisfactory and effective non-surgical treatment strategies, including drug therapy, are urgently warranted. MFS is a rare tumor that requires comprehensive preclinical research to develop promising drug therapies; however, only two MFS cell lines are publicly available worldwide. The present study reports two novel patient-derived MFS cell lines, NCC-MFS7-C1 and NCC-MFS8-C1. These cell lines have been extensively characterized for their genetic profile, proliferation, spheroid-forming capacity, and invasive behavior, confirming that they retain MFS hallmarks. Furthermore, we conducted comprehensive drug screening against these cell lines and six others previously established in our laboratory to identify potential therapeutic candidates for MFS. Among the screened agents, actinomycin D, bortezomib, and romidepsin demonstrated considerable antiproliferative effects that were superior to those of doxorubicin, a standard drug, highlighting their potential as novel drugs. In conclusion, NCC-MFS7-C1 and NCC-MFS8-C1 are valuable research resources that contribute to the understanding of the pathogenesis and development of novel therapies for MFS., (© 2024. The Author(s) under exclusive licence to Japan Human Cell Society.)

Published
2024
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49. Leishmanicidal phenolic compounds derived from Dalbergia cultrata .

Author

Mori-Yasumoto K, Hashimoto Y, Agatsuma Y, Fuchino H, Yasumoto K, Shirota O, Satake M, and Sekita S

Subjects
Humans, Phenols pharmacology, Phenols therapeutic use, Antiprotozoal Agents pharmacology, Benzofurans, Dalbergia, Leishmaniasis drug therapy
Abstract

Leishmaniasis is a protozoan tropical infection that is estimated to be more than 0.3 million new cases occur annually worldwide. A novel phenolic compound, cultratin A ( 1 ), was isolated as a leishmanicidal constituent from the timber of Dalbergia cultrata, along with three known neoflavanoids ( 2 , 3 , 4 ), two benzofurans ( 5 , 6 ), and two phenolic compounds ( 7 , 8 ). Their structures were determined using spectral methods. Among them, a new compound ( 1 ) and 4-( S )-methoxydalbergione ( 2 ) showed effective leishmanicidal activities (IC 50 : 2.0 and 2.6 μM, respectively), while compound 8 showed moderate activity (IC 50 : 11 μM). The cytotoxicity of compounds 1 and 2 was also weaker than that of the other compounds.

Published
2021
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50. Peptidomic analysis of the venom of the solitary bee Xylocopa appendiculata circumvolans .

Author

Kazuma K, Ando K, Nihei KI, Wang X, Rangel M, Franzolin MR, Mori-Yasumoto K, Sekita S, Kadowaki M, Satake M, and Konno K

Abstract

Background: Among the hymenopteran insect venoms, those from social wasps and bees - such as honeybee, hornets and paper wasps - have been well documented. Their venoms are composed of a number of peptides and proteins and used for defending their nests and themselves from predators. In contrast, the venoms of solitary wasps and bees have not been the object of further research. In case of solitary bees, only major peptide components in a few venoms have been addressed. Therefore, the aim of the present study was to explore the peptide component profile of the venom from the solitary bee Xylocopa appendiculata circumvolans by peptidomic analysis with using LC-MS., Methods: A reverse-phase HPLC connected to ESI-OrbiTrap MS was used for LC-MS. On-line mass fingerprinting was made from TIC, and data-dependent tandem mass spectrometry gave MSMS spectra. A major peptide component was isolated by reverse-phase HPLC by conventional way, and its sequence was determined by Edman degradation, which was finally corroborated by solid phase synthesis. Using the synthetic specimen, biological activities (antimicrobial activity, mast cell devaluation, hemolysis, leishmanicidal activity) and pore formation in artificial lipid bilayer were evaluated., Results: On-line mass fingerprinting revealed that the crude venom contained 124 components. MS/MS analysis gave 75 full sequences of the peptide components. Most of these are related to the major and novel peptide, xylopin. Its sequence, GFVALLKKLPLILKHLH-NH 2 , has characteristic features of linear cationic α-helical peptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, it can be predicted to adopt an amphipathic α-helix secondary structure. In biological evaluation, xylopin exhibited broad-spectrum antimicrobial activity, and moderate mast cell degranulation and leishmanicidal activities, but showed virtually no hemolytic activity. Additionally, the peptide was able to incorporate pores in artificial lipid bilayers of azolectin, confirming the mechanism of the cytolytic activity by pore formation in biological membranes., Conclusions: LC-ESI-MS and MS/MS analysis of the crude venom extract from a solitary bee Xylocopa appendiculata circumvolans revealed that the component profile of this venom mostly consisted of small peptides. The major peptide components, xylopin and xylopinin, were purified and characterized in a conventional manner. Their chemical and biological characteristics, belonging to linear cationic α-helical peptides, are similar to the known solitary bee venom peptides, melectin and osmin. Pore formation in artificial lipid bilayers was demonstrated for the first time with a solitary bee peptide.

Published
2017
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