Two new cytotoxic glycosides isolated from the green walnut husks of Juglans mandshurica Maxim

Two new diarylheptanoids from the green walnut husks of Juglans mandshurica Maxim

Chemical investigation on the 95% ethanol extract of green walnut husks of Juglans mandshurica Maxim. led to the isolation of two new diarylheptanoid compounds, including Juglanin K (1) and Myricananin I (2), together with ten known compounds (3-13). Their structures were elucidated by extensive analyses of comprehensive spectroscopic methods. The isolated compounds were evaluated for their antibacterial activities against Escherichia coli and Staphylococcus aureus. The results showed that compound 2 had moderate antibacterial activity with the MIC values of 0.313 and 0.156 mg/mL, respectively. compounds 1, 3-7 and 13 showed weakly antibacterial activities against Escherichia coli and Staphylococcus aureus with the MIC values of 0.625-2.5 mg/mL.

Juglans mandshurica Maxim.: A Review of Its Traditional Usages, Phytochemical Constituents, and Pharmacological Properties

Juglans mandshurica Maxim., also known as “Manchurian walnut” (Chinese) and “Onigurumi” (Japanese), is a medicinal plant widely distributed in Western and Central Asia, especially in China. It has been traditionally used to treat cancer, gastric ulcers, diarrhea, dysentery, dermatosis, uterine prolapse, and leukopenia. To date, more than 400 constituents including quinones (e.g. naphthoquinones, anthraquinones, naphthalenones, tetralones), phenolics, flavonoids, triterpenoids, coumarins, lignans, phenylpropanoids, diarylheptanoids, and steroids, were isolated and structurally identified from different plant parts of J. mandshurica. Among them, quinones, phenolics, triterpenoids, and diarylheptanoids, as the major bioactive substances, have been extensively studied and displayed significant bioactivity. Previous studies have demonstrated that J. mandshurica and a few of its active components exhibit a wide range of pharmacologically important properties, such as antitumor, immunomodulatory, anti-inflammatory, neuroprotective, anti-diabetic, antiviral, antimicrobial, and anti-melanogenesis activities. However, many investigations on biological activities were mainly based on crude extracts of this plant, and the major bioactive ingredients responsible for these bioactivities have not been well identified. Further in vitro and in vivo studies on the mechanisms of action of the pure bioactive compounds, and more elaborate toxicity studies as well as clinical studies are needed to ensure safety and effectiveness of the plant for human use. Taken together, the present review will provide some specific useful suggestions guide to further investigations and applications of this plant in the preparation of medicines and functional foods.

Antimicrobial and cytotoxic juglones from the immature exocarps of Juglans mandshurica

Juglonols A-C (1-3), three new juglone derivatives possessing a hydroxyethyl side chain, were isolated from an organic extract of the immature exocarps of Juglans mandshurica together with five known tetralones (4-8). Their structures were elucidated by extensive spectroscopic analyses and comparison with literature data. The new juglone derivatives exhibited inhibitory activities towards a panel of bacteria and fungi, as well as cancer cell lines. In contrast, the known tetralone homologues (4-8) appeared to be much less efficacy.

A new coumarin from Juglans mandshurica Maxim induce apoptosis in hepatocarcinoma cells

In this study, a new coumarin, juglansoside C (1) was isolated from the bark of Juglans mandshurica. Its chemical structure was identified by comprehensive spectroscopic analyses. The in vitro cytotoxicity assay showed that 1 exhibited moderate cytotoxicity against human hepatocellular carcinoma Hep3B cells with an IC₅₀ value of 70.9 μM. Furthermore, Annexin V-FITC/PI staining assay indicated that 1 markedly induced apoptosis in Hep3B cells.

A new diarylheptanoid and a new diarylheptanoid glycoside isolated from the roots of Juglans mandshurica and their anti-inflammatory activities

A new diarylheptanoid, (2S,3S,5S)-2,3,5-trihydroxy-1,7-bis(4-hydroxy- 3-methoxyphenyl)heptane (1), and a new diarylheptanoid glycoside, (2S,3S,5S)-2,3-dihydroxy-5-O-β-d-xylopyranosyl-7-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)heptane (2), together with three known compounds, rhoiptelol C (3), rhoiptelol B (4) and 3',4″-epoxy-2-O-β-d-glucopyanosyl-1-(4-hydroxyphenyl)- 7-(3-methoxyphenyl)heptan-3-one (5) were isolated from the roots of Juglans mandshurica (Juglandaceae). The structures of compounds 1 and 2 were identified based on HR-ESI-MS, 1D and 2D NMR spectroscopic methods. Compounds 1-5 were assayed for their inhibitory effects on the production of NO, TNF-α and IL-6 in LPS-stimulated RAW264.7 cells.