New 19(10 → 9)abeo-euphane-type triterpenoids from Trichilia dregeana leaves and NO production inhibitory activities.

Phytochemical investigation of the EtOAc soluble fraction from leaves of Trichilia dregeana Sond. (Meliaceae) afforded naturally rare four new pentacyclic triterpenoids (1-4), together with five known pentacyclic analogs (5-8, and 11) and two steroids (9 and 10). Their structures were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS data analyses. The absolute configuration of 1 was determined by using the single-crystal X-ray diffraction analysis. The nitric oxide (NO) production inhibitory assay indicated that the EtOAc fraction as well as 4 and 7 inhibited the NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with the IC50 values of 83.53 µg/mL and 81.31 and 85.71 µM, respectively. Compounds 1-4 are rare 19(10 â†’ 9)abeo-euphane-type triterpenoids bearing a 3,10-ether bridge. To the best of our knowledge, this study is the first isolation of triterpenoids with the 3,10-ether bridge in their skeleton from the genus Trichilia, providing new insights into the chemodiversity of the terpenoids in T. dregeana.

Phytoconstituents of Androstachys johnsonii Prain Prevent Reactive Oxygen Species Production and Regulate the Expression of Inflammatory Mediators in LPS-Stimulated RAW 264.7 Macrophages.

According to a survey, the medicinal use of Androstachys johnsonii Prain is kept secret by traditional healers. Considering that inflammation and oxidative stress are major risk factors for the progression of various chronic diseases and disorders, we resolved to investigate the antioxidant and anti-inflammatory potentials of A. johnsonii using in vitro and cell-based assays. The antioxidant activity of A. johnsonii hydroethanolic leaf extract (AJHLE) was evaluated using the ABTS, DPPH, and FRAP assays. Its cytotoxic effect was assessed on RAW 264.7 macrophages using an MTT assay. Then, its anti-inflammatory effect was evaluated by measuring the NO production and 15-LOX inhibitory activities. Moreover, its preventive effect on ROS production and its regulatory effect on the expression of pro-inflammatory mediators such as IL-1ß, IL-10, TNF-α, and COX-2 were determined using established methods. AJHLE strongly inhibited radicals such as ABTS•+, DPPH•, and Fe3+-TPTZ with IC50 values of 9.07 µg/mL, 8.53 µg/mL, and 79.09 µg/mL, respectively. Additionally, AJHLE induced a significant (p < 0.05) cytotoxic effect at 100 µg/mL, and when tested at non-cytotoxic concentrations, it inhibited NO and ROS production in LPS-stimulated RAW 264.7 macrophages in a concentration-dependent manner. Furthermore, AJHLE showed that its anti-inflammatory action occurs via the inhibition of 15-LOX activity, the downregulation of COX-2, TNF-α, and IL-1ß expression, and the upregulation of IL-10 expression. Finally, chemical investigation showed that AJHLE contains significant amounts of procyanidin, epicatechin, rutin, and syringic acid which support its antioxidant and anti-inflammatory activities. These findings suggest that A. johnsonii is a potential source of therapeutic agents against oxidative stress and inflammatory-related diseases.

Unravelling the Influence of Chlorogenic Acid on the Antioxidant Phytochemistry of Avocado (Persea americana Mill.) Fruit Peel.

Oxidative stress is pivotal in the pathology of many diseases. This study investigated the antioxidant phytochemistry of avocado (Persea americana Mill.) peel. Different solvent extracts (dichloromethane, ethyl acetate, methanol, and water) of avocado peel were subjected to total phenol and flavonoid quantification, as well as in vitro radical scavenging and ferric reducing evaluation. The methanol extract was subjected to gradient column chromatographic fractionation. Fraction 8 (eluted with hexane:chloroform:methanol volume ratio of 3:6.5:0.5, respectively) was subjected to LC-MS analysis. It was assessed for cellular inhibition of lipid peroxidation and lipopolysaccharide (LPS)-induced ROS and NO production. The DPPH radical scavenging mechanism of chlorogenic acid was investigated using Density Functional Theory (DFT). The methanol extract and fraction 8 had the highest phenol content and radical scavenging activity. Chlorogenic acid (103.5 mg/mL) and 1-O-caffeoylquinic acid (102.3 mg/mL) were the most abundant phenolics in the fraction. Fraction 8 and chlorogenic acid dose-dependently inhibited in vitro (IC50 = 5.73 and 6.17 µg/mL) and cellular (IC50 = 15.9 and 9.34 µg/mL) FeSO4-induced lipid peroxidation, as well as LPS-induced ROS (IC50 = 39.6 and 28.2 µg/mL) and NO (IC50 = 63.5 and 107 µg/mL) production, while modulating antioxidant enzyme activity. The fraction and chlorogenic acid were not cytotoxic. DFT analysis suggest that an electron transfer, followed by proton transfer at carbons 3'OH and 4'OH positions may be the radical scavenging mechanism of chlorogenic acid. Considering this study is bioassay-guided, it is logical to conclude that chlorogenic acid strongly influences the antioxidant capacity of avocado fruit peel.

Dryoptkirbioside, A New Fructofuranoside Glycerol, and Other Constituents from Dryopteris kirbi Hook et Grav Rhizomes.

A new fructofuranoside glycerol, dryoptkirbioside (1), along with thirteen known compounds (2-14), was isolated from the MeOH extract of Dryopteris kirbi rhizomes by silica gel column chromatography, Sephadex LH-20 column chromatography, and semipreparative HPLC. The structure of the new compound was determined by analyses of its spectroscopic data including nuclear magnetic resonance (NMR), and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) and chemical conversions. The hexane-soluble portion and the EAFA fraction showed strong activities against lung (A549), breast (MCF-7), and cervical (HeLa) human cancer cell lines (IC50 values ranging from 4.0 to 8.8 µg/mL). Aspidinol P (5) and aspidinol B (6) exhibited moderate to low cytotoxicity on the three cell lines (IC50 values ranging from 20.4 to 58.7 µM). The MeOH extract and hexane-soluble portion had excellent activities against Staphylococcus aureus and Bacillus subtilis (MICs 11.7 and 23.4 µg/mL), whereas the AcOEt- and BuOH-soluble portions were significantly active on S. aureus (MICs 46.9 and 93.8 µg/mL). The main fractions EAFB , EAFC and nBFB displayed excellent activity against S. aureus (MICs 11.7 and 23.4 µg/mL). Aspidinol B (6) had significant activity, while aspidinol P (5) was moderately active against S. aureus and B. subtilis (MICs 42.0 and 89.5 µM).