Results 131 to 140 of about 2,232 (157)

Bisprenyl naphthoquinone and chlorinated calcimycin congener bearing thiazole ring from an actinomycete of the genus Phytohabitans

The Journal of Antibiotics, 2022
A bisprenyl naphthoquinone, phytohabinone (1), and a calcimycin congener with unusual modifications, phytohabimicin (2), were isolated from the culture extract of Phytohabitans sp. RD003013. The structures of 1 and 2 were determined by NMR and MS analyses, and the absolute configuration of 2 was established by using electronic circular dichroism (ECD ...
Enjuro Harunari, Shunsuke Mae, Keisuke Fukaya, Etsu Tashiro, Daisuke Urabe, Yasuhiro Igarashi   +5 more
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ChemInform Abstract: A Total Synthesis of Polyether Antibiotic (‐)‐A23187 (Calcimycin).

ChemInform, 1987
AbstractThe key step in the synthesis of the polyether antibiotic calcimycin is the stereospecific cyclization of the hydroxy ketone (III), yielding the spiro‐acetal (IV).
D. P. NEGRI, Y. KISHI
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Structure cristalline du complexe de magnésium de la calcimycine (A. 23187)

Canadian Journal of Chemistry, 1985
The 1:2 magnesium ion complex of the antibiotic calcimycine (A. 23187) crystallizes in the space group P21, with cell dimensions a = 11.152(2), b = 27.684(2), c = 10.168(2) Å, β = 107.02(2)°, and Z = 2. The structure was refined to an R = 0.063 based on 3473 observed reflections. The octahedral coordination of the Mg2+ ion is highly symmetrical.
Marc Alléaume, Yvette Barrans
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Total Synthesis of Antibiotic A23187 (Calcimycin) from D-Glucose: Communication

Journal of Carbohydrate Chemistry, 1984
Abstract Antibiotic A23187 1 is a cation ionophore highly specific for Ca2+. Because of its unique dioxaspiro ring structure as well as its biological activities,2 several synthetic approaches to the compound have been reported.3 We report here the first example of the total synthesis of based on the use of a carbohydrate template.4 The target ...
Yoshiaki Nakahara, Akira Fujita, Tomoya Ogawa   +2 more
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Interaction of the calcium ionophore A.23187 (Calcimycin) with Bacillus cereus and Escherichia coli

Letters in Applied Microbiology, 1993
Ionophores isolated from bacterial strains, and especially A.23187, are efficient antibiotics against Gram-positive bacteria and devoid of activity on Gram-negative species. This difference in activity was attributed to the outer membrane of Gram-negative bacteria which is presumably impermeable to these very hydrophobic compounds. In this context, the
J. Guyot, G. Jeminet, Michelle Prudhomme, Martine Sancelme, R. Meiniel   +4 more
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Calcimycin induced IL-12 production inhibits intracellular mycobacterial growth by enhancing autophagy

Cytokine, 2018
Previously, we reported pivotal role of P2RX7 in augmenting autophagy in THP-1 cells upon Calcimycin treatment by modulating intracellular Calcium regulated ATP production but the role of immune modulators in Calcimycin induced autophagy is not known. In this study, we demonstrate that treatment with Calcimycin in PMA (Phorbol 12-myristate 13-acetate ...
Shradha Mawatwal, Assirbad Behura, Abtar Mishra, Ramandeep Singh, Rohan Dhiman   +4 more
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Characterization of the N-methyltransferase CalM involved in calcimycin biosynthesis by Streptomyces chartreusis NRRL 3882

Biochimie, 2013
Calcimycin is a rare divalent cation specific ionophore antibiotic that has many biochemical and pharmaceutical applications. We have recently cloned and sequenced the Streptomyces chartreusis calcimycin biosynthesis gene cluster as well as identified the genes required for the synthesis of the polyketide backbone of calcimycin. Additional modifying or
Qiulin, Wu, Lixia, Gou, Shuangjun, Lin, Jingdan, Liang, Jun, Yin, Xiufen, Zhou, Linquan, Bai, Derong, An, Zixin, Deng, Zhijun, Wang   +9 more
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Formal synthesis of (-)-calcimycin (A-23187) via the 3-methyl-.gamma.-butyrolactone approach

The Journal of Organic Chemistry, 1989
La methode presentee conduit a l'acide (+) [(pyrrolecarbonyl-2]-1″ ethyl-6' perhydro trimethyl-3',5,5'] spirobi-2:2'-pyranne acetique ...
Frederick E. Ziegler, William T. Cain
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ChemInform Abstract: TOTAL SYNTHESIS OF ANTIBIOTIC A23187 (CALCIMYCIN) FROM D‐GLUCOSE

Chemischer Informationsdienst, 1985
AbstractEntsprechend dem Reaktionsschema werden zunächst die chiralen Synthone (V) und (VII) dargestellt und anschließend zu (VIIIa) kondensiert, aus dem über mehrere Stufen die Verbindung (X) erhalten wird.
Y. NAKAHARA, A. FUJITA, T. OGAWA
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ChemInform Abstract: Synthesis of Calcimycin (A 23187) Biomimetic Models. Preparation of Spiroacetal Intermediate.

ChemInform, 1988
AbstractThe reaction between the pyrroles (I) and the aldehyde (II) represents the starting step in the synthesis of the spiroacetals (III).
M. PRUDHOMME, G. DAUPHIN, G. JEMINET
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