- Five phloroglucinol-monoterpene adducts from Eucalyptus grandis
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Five new euglobals possessing the phloroglucinol-monoterpene structure, euglobals G8-G12, together with a known euglobal-IIc were isolated from the hexane fraction of the methanol extract of the leaves of Eucalyptus grandis. Euglobal-G8 is an adduct of formyl-isovaleroyl-phtoroglucinol and γ- terpinene whereas -G9, -G10 and -G11 have the same phloroglucinol moiety fused with α-terpinene, while Euglobal-G12 has terpinolene fused with the same phloroglucinol moiety. The structures of these compounds were elucidated on the basis of spectral evidences. Biomimetic synthesis of euglobals suggests that these compounds are derived biogenetically by the Diels-Alder type cycloaddition of the corresponding terpenes with an ortho-quinone methide generated from grandinol.
- Umehara, Kazuhiro,Singh, Inder Pal,Etoh, Hideo,Takasaki, Midori,Konoshima, Takao
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- Derivatives of Natural Product Agrimophol as Disruptors of Intrabacterial pH Homeostasis in Mycobacterium tuberculosis
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This article reports the rational medicinal chemistry of a natural product, agrimophol (1), as a new disruptor of intrabacterial pH (pHIB) homeostasis in Mycobacterium tuberculosis (Mtb). Through the systematic investigation of the structure-activity relationship of 1, scaffold-hopping of the diphenylmethane scaffold, pharmacophore displacement strategies, and studies of the structure-metabolism relationship, a new derivative 5a was achieved. Compound 5a showed 100-fold increased potency in the ability to reduce pHIB to pH 6.0 and similarly improved mycobactericidal activity compared with 1 against both Mycobacterium bovis-BCG and Mtb. Compound 5a possessed improved metabolic stability in human liver microsomes and hepatocytes, lower cytotoxicity, higher selectivity index, and similar pKa value to natural 1. This study introduces a novel scaffold to an old drug, resulting in improved mycobactericidal activity through decreasing pHIB, and may contribute to the critical search for new agents to overcome drug resistance and persistence in the treatment of tuberculosis.
- Wu, Jie,Mu, Ran,Sun, Mingna,Zhao, Nan,Pan, Miaomiao,Li, Hongshuang,Dong, Yi,Sun, Zhaogang,Bai, Jie,Hu, Minwan,Nathan, Carl F.,Javid, Babak,Liu, Gang
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p. 1087 - 1104
(2019/05/22)
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- Novel diphenylmethyl compounds having mycobacterium tuberculosis inhibitory activity
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The invention relates to novel diphenylmethyl derivatives having mycobacterium tuberculosis inhibitory activity and a preparation method thereof and particularly relates novel diphenylmethyl derivatives having activity for inhibiting replicative and non-replicating mycobacterium tuberculosis and a preparation method thereof. In particular, the invention relates to compounds shown in the formula (I) or all possible isomers, prodrugs, pharmaceutically acceptable salts, solvates or hydrates thereof, wherein the variables are as described in the specification. The invention also relates to the preparation method of the compounds and their pharmaceutical compositions and a use of the compounds in preparation of drugs for treating mycobacterium tuberculosis infection-caused diseases.
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Paragraph 0270; 0271; 0276; 0277; 0308-0311
(2019/02/13)
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- Electrochemical synthesis of euglobal-G1, -G2, -G3, -G4, -T1 and -IIc
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Six natural euglobals were synthesized by electrochemical methods. In a key step, cycloaddition between in situ generated quinomethanes and terpenes was performed on the surface of PTFE-fibre coated electrode to give natural products using 2,3-dichloro-5,
- Chiba, Kazuhiro,Arakawa, Takaaki,Tada, Masahiro
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p. 2939 - 2942
(2007/10/03)
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- Synthesis of euglobal-G3 and -G4
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The first, concise synthesis of euglobals is accomplished by biomimetic cycloaddition of β-pinene and quinone methides generated by oxidation of grandinol.
- Chiba, Kazuhiro,Arakawa, Takaaki,Tada, Masahiro
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p. 1763 - 1764
(2007/10/03)
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