- Synthesis of lamellarins via regioselective assembly of 1,2-diarylated [1]benzopyrano[3,4-b]pyrrol-4(3H)-one core
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A modular synthesis of lamellarins has been developed. The key reactions in this synthesis are the assembly of 1,2-diarylated [1]benzopyrano- [3,4-b]pyrrol-4(3H)-ones from a preexisting [1]benzopyrano[3,4-b]pyrrol- 4(3H)-one core and the appropriate arylb
- Fukuda, Tsutomu,Katae, Takatoshi,Harada, Issei,Iwao, Masatomo
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p. 950 - 971
(2017/07/28)
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- Synthesis, structure-activity relationships, and mechanism of action of anti-HIV-1 lamellarin α 20-sulfate analogues
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Lamellarin α and six different types of lamellarin α 20-sulfate analogues were synthesized and their structure-activity relationships were investigated using a single round HIV-1 vector infection assay. All lamellarin sulfates having pentacyclic lamellarin core exhibited anti-HIV-1 activity at a 10 μM concentration range regardless of the number and position of the sulfate group. On the other hand, non-sulfated lamellarin α and ring-opened lamellarin sulfate analogues did not affect HIV-1 vector infection in similar concentrations. The lamellarin sulfates utilized in this study did not exhibit unfavorable cytotoxic effect under the concentrations tested (IC50 > 100 μM). Confocal laser scanning microscopic analysis indicated that hydrophilic lamellarin sulfates were hardly incorporated in the cell. HIV-1 Env-mediated cell-cell fusion was suppressed by lamellarin sulfates. These results suggested that lamellarin sulfates have a novel anti-HIV-1 activity besides the previously reported integrase activity inhibition, possibly at a viral entry step of HIV-1 replication.
- Kamiyama, Haruka,Kubo, Yoshinao,Sato, Hironori,Yamamoto, Naoki,Fukuda, Tsutomu,Ishibashi, Fumito,Iwao, Masatomo
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p. 7541 - 7550
(2012/01/13)
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- Divergent synthesis of lamellarin α 13-sulfate, 20-sulfate, and 13,20-disulfate
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A divergent synthesis of three sulfate derivatives of lamellarin α, namely, lamellarin α 13-sulfate (2), 20-sulfate (1), and 13,20-disulfate (4) has been achieved via a common intermediate (6) in which 13-OH and 20-OH of the lamellarin core are differentially protected by MOM and benzyl groups, respectively. Compound (6) in turn was prepared using sequential Suzuki-Miyaura coupling of 3,4-dihydroxypyrrole bistriflate (7) as a key reaction.
- Fukuda, Tsutomu,Ohta, Takeshi,Saeki, Sho,Iwao, Masatomo
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scheme or table
p. 841 - 846
(2010/10/05)
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- Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings
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(Chemical Equation Presented) Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and α-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography.
- Ploypradith, Poonsakdi,Petchmanee, Thaninee,Sahakitpichan, Poolsak,Litvinas, Nichole D.,Ruchirawat, Somsak
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p. 9440 - 9448
(2007/10/03)
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- Total synthesis and evaluation of lamellarin α 20-Sulfate analogues
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In order to explore the influence of sulfate groups on the bioactivity profiles of marine alkaloids of the lamellarin class, three such alkaloids, lamellarin α lamellarin α 13,20-disulfate and H, were synthesized and their activities against HIV-1 integrase and cancer cell ines were compared with those of lamellarin α 20-sulfate, which is a selective inhibitor of HIV-1 integrase. Lamellarin α does not inhibit HIV-1 integrase but shows moderate cytotoxicity with good cell line selectivity. Lamellarin α13,20-disulfate is a moderate inhibitor of both HIV-1 integrase and cancer cell lines. Lamellarin H is a more potent inhibitor of HIV-1 integrase but lacked the specificity required to be medicinally useful. Copyright
- Ridley, Christian P,Reddy, M. Venkata Rami,Rocha, Genalyn,Bushman, Frederic D,Faulkner
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p. 3285 - 3290
(2007/10/03)
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