ミャンマー産植物Premna serratifoliaとJatropha multifida及び海綿Clathria proliferaに含まれるメラニン産生制御成分に関する研究

富山大学・富医薬博甲第305号・禹 昭年・2019/03/26当該博士論文は以下の項評論文で構成されています。①Woo, SY., Win, N.N., Wong, C.P. et al. Two new pyrrolo-2-aminoimidazoles from a Myanmarese marine sponge, Clathria prolifera, J Nat Med (2018) 72: 803-807. https://doi.org/10.1007/s11418-018-1205-y This is a pre-print of an article published in Journal of Natural Medicines. The final authenticated version is available online at: https://doi.org/10.1007/s11418-018-1205-y”.②So-Yeun Woo et al. Lignans with melanogenesis effects from Premna serratifolia wood, Fitoterapia (2019) 133:35-42. https://doi.org/10.1016/j.fitote.2018.12.008③So-Yeun Woo et al. A New Tetrahydrofuran Lignan from Premna serratifolia Wood, Natural Product Communications (2019) 14:113-116. https://doi.org/10.1177/1934578X1901400130富山大

Identification of Pyridinium with Three Indole Moieties as an Antimicrobial Agent

A novel pyridinium with three indole moieties, tricepyridinium, was obtained from the culture of an <i>Escherichia coli</i> clone incorporating metagenomic libraries from the marine sponge <i>Discodermia calyx</i>. For the important structural elements of tricepyridinium to be investigated for antibacterial activity, tricepyridinium and its analogues were chemically synthesized. Tricepyridinium had antimicrobial activity, but not against <i>E. coli</i>, and cytotoxicity against P388 cells. Additional bioassays with its synthetic analogues revealed that the intriguing combination of the indole moieties, most likely derived from three tryptamines, as well as the pyridinium moiety were chiefly responsible for its potent biological activities

Bisleuconothines B–D, Modified Eburnane–Aspidosperma Bisindole Alkaloids from Leuconotis griffithii

Three new bisindole alkaloids, bisleuconothines B-D (1-3), were isolated from the bark of Leuconotis griffithii. Their structures were elucidated by 1D and 2D NMR spectroscopy and DFT calculations. Bisleuconothine B (1) is the first monoterpene indole alkaloid dimer featuring bridges between both C-16-C-10′ and C-2-O-C-9′. All compounds were deemed noncytotoxic (IC50 > 10 μM) when tested against A549 human lung adenocarcinoma cells

Polyisoprenylated Acylphloroglucinols from Garcinia nervosa

Two new polyisoprenylated acylphloroglucinols, 7-epi-isoxanthochymol and 7-epi-cycloxanthochymol (1 – 2), were isolated from the barks of Garcinia nervosa together with their 7-epimers isoxanthochymol (3) and cycloxanthochymol (4). Their structures were determined on the basis of NMR spectroscopic data. The cytotoxic activity of the isolated compounds against HL-60, MCF-7 (human breast adenocarcinoma), A549 (human lung adenocarcinoma) and HepG2 (human hepatocellular carcinoma) cells were evaluated, and all compounds showed cytotoxic activity against all cell lines

Ceramicines M–P from Chisocheton ceramicus: isolation and structure–activity relationship study

Ceramicines are a series of limonoids which were isolated from the bark of Malaysian Chisocheton ceramicus (Meliaceae) and show various biological activities. Ceramicine B, in particular, has been reported to show a strong lipid droplet accumulation (LDA) inhibitory activity on a mouse pre-adipocyte cell line (MC3T3-G2/PA6). With the purpose of discovering compounds with stronger activity than ceramicine B, we further investigated the constituents of C. ceramicus. As a result, from the bark of C. ceramicus four new ceramicines (ceramicines M–P, 1–4) were isolated, and their structures were determined on the basis of NMR and mass spectroscopic analyses in combination with NMR chemical shift calculations. LDA inhibitory activity of 1–4 was evaluated. Compounds 1–3 showed LDA inhibitory activity, and 3 showed better selectivity than ceramicine B while showing activity at the same order of magnitude as ceramicine B. Since 3, which possess a carbonyl group at C-7, showed better selectivity than 5, which possess a 7α-OH group, while showing activity at the same order of magnitude as 5, we also investigated the effect of the substituent at C-7 by synthesizing several derivatives and evaluating their LDA inhibitory activity. Accordingly, we confirmed the importance of the presence of a 7α-OH group to the LDA inhibitory activity