Total Synthesis of (±)-Crinine via the Regioselective Stille Coupling and Diels−Alder Reaction of 3,5-Dibromo-2-pyrone

The regioselective synthesis and Diels−Alder cycloaddition of 3-(3,4-methylenedioxyphenyl)-5-bromo-2-pyrone provided a new synthetic route to crinine. The vinyl bromide group can be used as a handle for further derivatization

Total Synthesis of (±)-Joubertinamine from 3-(3,4-Dimethoxyphenyl)-5-bromo-2-pyrone

The regioselective synthesis and Diels−Alder cycloaddition of 3-(3,4-dimethoxyphenyl)-5-bromo-2-pyrone provided a new efficient synthetic route to joubertinamine (9.6% total yield over 10 steps)

Intramolecular Imino Diels−Alder Approach to the Synthesis of the Aspidosperma Alkaloid from 3,5-Dibromo-2-pyrone

A new synthetic route to the key framework of aspidosperma alkaloid was devised from the cycloadduct of 3-(2-nitrophenyl)-5-bromo-2-pyrone via intramolecular imino Diels−Alder reaction

Total Syntheses of (±)-Crinine, (±)-Crinamine, and (±)-6a-<i>epi</i>-Crinamine via the Regioselective Synthesis and Diels−Alder Reaction of 3-Aryl-5-bromo-2-pyrone

We have devised a new unified synthetic protocol to (±)-crinine, (±)-crinamine, and (±)-6a-epi-crinamine from the Diels−Alder cycloadduct of 3-(3,4-methylenedioxyphenyl)-5-bromo-2-pyrone with TBS vinyl ether. The requisite 3-(3,4-methylenedioxyphenyl)-5-bromo-2-pyrone was prepared from the C3-selective Stille coupling reaction of 3,5-dibromo-2-pyrone. Also noted is that the vinyl bromide can be used as a handle for further derivatization

sj-docx-1-npx-10.1177_1934578X221148621 - Supplemental material for Two New Nitrogen-Containing Glycosides From <i>Stixis scandens</i>

Supplemental material, sj-docx-1-npx-10.1177_1934578X221148621 for Two New Nitrogen-Containing Glycosides From Stixis scandens by Tran Thi Yen, Nguyen Thanh Tam, Nguyen Thanh Thi Kim and Vo Ngoc Binh, Nguyen Thao Kim Nu, Ngo Quoc Anh in Natural Product Communications</p

New phenolics from <i>Uraria crinita</i> (L.) DC

Reinvestigation of a methanol extract of Uraria crinita afforded a new 3- hydroxyisoflavanone, 3,5,7,2',4'-pentahydroxyisoflavanone (1), two new monoaryl glucosides, 3,4-dimethoxyphenyl 1-O-(6′-O-acetyl)-β-D-glucopyranoside (2) and 3,4,5-trimethoxyphenyl 1-O-(6′-O-acetyl)-β-D-glucopyranoside (3), in addition to three known compounds, 3′-O-methylorobol (4), robusflavone B (5), and apigenin (6). The structural elucidation of these compounds was achieved by analyses of their spectroscopic data (HR-ESI-MS, 1 D- and 2 D-NMR) and acidic hydrolysis. The U. crinita extracts and compounds 1–6 exhibited weak or no cytotoxic activity against KB, HepG2, Lu and MCF7 cell lines.</p

A new isoflavanone from <i>Uraria crinita</i>

A new isoflavanone, (3S)-5,7-dihydroxy-2′,3′,4′-trimethoxy-6,5′-diprenylisoflavanone (1) and eight known compounds including five flavones (2–6), two triterpenes (7–8) and a steroid (9) were isolated from the whole plant of Uraria crinita (Leguminosae). The structure of 1 was elucidated by detailed spectroscopic means including IR, HR-ESI-MS, 1D and 2D NMR, and CD data. Compounds 1–9 were evaluated for their cytotoxicity against four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Compound 1 showed cytotoxic activity against the tested cell lines with IC50 values of 33.2, 29.4, 59.6 and 66.8 μM, respectively.</p

Chemical constituents of <i>Impatiens chapaensis</i> Tard. and their <i>α</i>-glucosidase inhibition activities

Sixteen compounds (1-16) were isolated from Impatiens chapaensis. Chemical structures were determined by spectroscopic analyses and comparisons with previously published data. This report is the first to identify compounds 1, 5–7, 10, 12–14, and 16 from the genus Impatiens. Seven chosen isolates (5, 7, 10, 11, 12, 15, and 16) were submitted for α-glucosidase inhibition assays with acarbose as the positive control (IC50 = 227.14 ± 13.71 µM). Flavonoid 5 exhibited a significant inhibitory effect (IC50 = 101.00 ± 9.01 µM).</p

Pro-apoptoticeffect of diterpenoids from <i>Fokienia hodginsii</i> on acute myeloid leukemia cells

Previously, we isolated four known diterpenoids, trans-communic acid (1), 13-oxo-15,16-dinor-labda-8(17), 11E-diene-19-oic acid (2), 3β-hydroxytotarol (3), and totarolone (4) from Fokienia hodginsii leaves. Further study demonstrated the antiproliferative activity of all four compounds in acute myeloid leukemia (OCI-AML) cells due to impaired cell cycle progression. Interestingly, 3β-hydroxytotarol (3) had very powerful bioactivity at low concentrations (5 µg/mL). </p