A new phenolic compound from Phedimus middendorffianus with antiproliferative activity

Four new compounds from fruits of Hypericum patulum Thunb

A new naphthoquinone, patulumnaphthoquinone A (1) and three new glycosides, patulumside B (2), patulumside C (3) and patulumside D (4) were isolated from the 30% ethanol extract of the fresh ripe fruits of Hypericum patulum Thunb. using column chromatography techniques. The structures of these compounds including absolute configurations were elucidated on the basis of HRESIMS, NMR spectroscopic analyses, calculated electronic circular dichroism spectra and comparison with the literatures.

Methyl gallate from Camellia nitidissima Chi flowers reduces quorum sensing related virulence and biofilm formation against Aeromonas hydrophila

Aeromonas hydrophila, a Gram-negative zoonotic bacterium, causes high mortality in fish farming and immunocompromised patients. This study aimed to extract methyl gallate (MG) from the flowers of Camellia nitidissima Chi and evaluate its potential as a quorum sensing inhibitor (QSI) against Aeromonas hydrophila SHAe 115. MG reduced QS-associated virulence factors, including hemolysis, protease, and lipase, while impairing swimming motility and biofilm formation. Additionally, MG down-regulated positive regulatory genes (ahyR, fleQ) and up-regulated negative regulators (litR, fleN). This highlights MG's promise as a potent QSI for A. hydrophila SHAe 115, advancing strategies against infections in aquaculture and human health.

Two New Lactam Derivatives from Micromelum falcatum (Lour.) Tan. with Brine Shrimp Larvae Toxicity

Chemical investigation of the stems of Micromelum falcatum (Lour.) Tan. led to the isolation of two new lactam derivatives, named 3-(hydroxy(10-hydroxyphenyl)methyl)-4-(16-hydroxyphenyl)-1-methylpyrrolidin-2-one (1) and 3-(hydroxy(10-hydroxy-9-methoxyphenyl)methyl)-4-(16-hydroxyphenyl)-1-methylpyrrolidin-2-one (2), along with five known compounds, trans-4-hydroxycinnamic acid (3), 4-hydroxybenzaldehyde (4), m-hydroxybenzoic acid (5), p-hydroxybenzoic acid (6), and gallic acid (7). Their structures were determined on the basis of spectroscopic studies, including nuclear magnetic resonance (NMR) spectrum, mass spectrometry (MS) data, ultraviolet (UV) spectrum, infrared (IR) data, and comparison with the literature. All compounds were evaluated for toxicity against brine shrimp larvae and cytotoxicity to HeLa and HepG-2 cells. Compounds 1-2 exhibited moderate brine shrimp larvae toxicity with an LC50 value of 50.6 and 121.8 μg mL-1, respectively.

In vitro antiglycation and antioxidant properties of Eugenia pyriformis leaves and fruits

Eight phenolic compounds were isolated from Eugenia pyriformis leaves fraction by semi-preparative HPLC and characterized by Nuclear Magnetic Resonance (NMR) and mass spectrometry (ESI-MS). Five compounds were isolated and identified for the first time in E. pyriformis species, while this is the first report of the accumulation of isoquercitrin, quercitrin, and the aglycone quercetin in its leaves. E. pyriformis leaves and fruits extracts, as well as the compounds isolated from the leaves most active fraction, were evaluated for their antiglycation and antioxidant activities. The mixture of myricetin-3-O-(2″-O-galloyl)-α-L-rhamnoside and myricetin-3-O-(4″-O-galloyl)-α-L-rhamnoside showed the highest antiglycation activity. These results suggest that this species is a promising source of bioactive compounds. Further studies to investigate the inhibition of the glycation process in vivo are necessary to evaluate its use in the treatment and/or prevention of advanced glycation end-products (AGEs)-associated diseases.