Eglerisine, a Novel Sesquiterpenoid Tropolone from Dulacia egleri with Antiproliferative Effect against an Acute Myeloid Leukemia Lineage.

Chemical investigation of the stems of Dulacia egleri resulted in the isolation of eglerisine (1: ), a compound with a rare sesquiterpenoid tropolone skeleton. Its structure was determined by analysis of spectrometric and spectroscopic data, including HRESIMS, 1D, and 2D NMR. The antiproliferative effects of eglerisine were tested in human leukemia lineages. In the Kasumi-1 lineage, an acute myeloid leukemia cell line, eglerisine reduced cell metabolism, as determined by the resazurin assay. Eglerisine did not induce cell death by either apoptotic or necrotic mechanisms. However, a reduction of the absolute number of cells was observed. Eglerisine induced cell cycle arrest after 72 h of treatment by phosphorylation of H2AX histone, reducing the S phase and increasing the G2 phase of the cell cycle.

Anti-inflammatory activity of 4',6,7-trihydroxy-5-methoxyflavone from Fridericia chica (Bonpl.) L.G.Lohmann.

Fridericia chica, Bignoniaceae, is a tropical tree-creeper used as a traditional remedy for a number of diseases, highlighting inflammation. Our objective was to corroborate the popular anti-inflammatory use of the hydroethanolic extract from the leaves (HEFc) and of its isolated 4',6,7-trihydroxy-5-methoxyflavone (5-O-methylscutellarein) [1], described here for the first time. Quantitative analysis indicated 8.77 ± 0.23 mg/g of this compound in the extract. Neither HEFc nor [1] was cytotoxic in vitro. In LPS-induced peritonitis in mice, oral pre-treatment with HEFc or [1] led to decreased leukocyte migration to the peritoneal cavity and a reduction in the concentrations of pro-inflammatory cytokines (TNFα and IL-1ß). Also, the anti-inflammatory cytokine IL-10 was enhanced following treatment with [1]. Overall, these results validate the traditional use of Fridericia chica as anti-inflammatory, and indicate that the compound 5-O-methylscutellarein may participate in this effect.

4'-Hydroxy-6,7-methylenedioxy-3-methoxyflavone: A novel flavonoid from Dulacia egleri with potential inhibitory activity against cathepsins B and L.

A new flavone, 4'-hydroxy-6,7-methylenedioxy-3-methoxyflavone 1, and two other nucleosides, ribavirin 2 and adenosine 3, were isolated from the leaves of Dulacia egleri. The nucleosides were identified by spectroscopic techniques (1D, 2D-NMR) while the structure of the flavonoid was established by 1D, 2D-NMR analysis, including HRESIMS data. The results obtained in the biological assays showed that the compound 1 was able to inhibit cathepsins B and L with IC50 of 14.88 ±â€¯0.18 µM and 3.19 ±â€¯0.07 µM, respectively. The mechanism of inhibition for both enzymes were determined showing to be competitive at cathepsin B with Ki = 12.8 ±â€¯0.6 µM and non-linear non-competitive with positive cooperativity inhibition at cathepsin L with Ki = 322 ±â€¯33 µM, αKi = 133 ±â€¯15 µM, ßKi = 5.14 ±â€¯0.41 µM and γKi = 13.2 ±â€¯13 µM.

Chemical constituents and antileukemic activity of Eugenia dysenterica.

The study about Eugenia dysenterica led to the isolation of 3-acetyl-urs-12-en-28-oic (1), 3-acetyl-olean-12-en-28-oic acid (2) and isoquercetin (3) from the stem barks, and of 3-O-ß-glucopyranosyl-ß-sitosterol (4), methyl 3-hydroxy-4-methoxybenzoate (5), methyl 4-hydroxyphenyl propionate (6), E-methyl-4-hydroxycinnamate (7), quercetin-3-O-(6ꞌꞌ-O-galloyl)-ß-d-glucopyranoside (8) and quercetin-3-O-ß-d-galactopyranoside (9) from the leaves. The structures 1-9 were set through the analysis of their NMR spectroscopic data. Compounds 2, 3 and 5-8 were reported for the first time in the Eugenia genus. Compound 8 reduced cell viability and presented IC50 values 40.3 and 36.7 µM, for the CCRF-CEM and the Kasumi-1 cells, respectively.