Prenylated benzophenone derivatives from Hypericum patulum

Formohyperins G-L, polycyclic prenylated benzoylphloroglucinols from the flowers of Hypericum formosanum

Phytochemical study on the flowers of Hypericum formosanum Maxim. (Hypericaceae) led to the isolation of formohyperins G-L (1-6), whose structures were assigned by detailed spectroscopic analysis. Formohyperins G-L (1-6) are new benzoylphloroglucinols substituted by a C10 unit, a prenyl group, and a methyl group. Formohyperins G-J (1-4) possess a 6/6/6-tricyclic structure, while formohyperins K (5) and L (6) have a unique 6/6/5/4-tetracyclic structure consisting of cyclohexadienone, dihydropyrane, cyclopentane, and cyclobutane rings. The absolute configurations of 1-6 were deduced by analysis of the ECD spectra. Formohyperins G-J (1-4) and L (6) were found to show potent inhibitory activities against IL-1β release from LPS-treated murine microglial cells with EC50 values of 5.0, 10.9, 6.3, 10.8, and 13.7 µM, respectively, without cytotoxicity. 6-O-Methylformohyperins G (1a) and I (3a) also exhibited the inhibitory activities with EC50 values of 4.7 and 2.7 µM, respectively, although they were cytotoxic against microglial cells.

New Monoterpenoid Glycosides from the Fruits of Hypericum patulum Thunb

The whole Hypericum patulum Thunb. plant is utilized in traditional medicine for its properties of clearing heat, detoxifying, soothing meridians, relaxing the liver, and stopping bleeding. In folk medicine, it is frequently used to treat hepatitis, colds, tonsillitis, and bruises. Phytochemical investigation of a 30% ethanol extract of the fresh ripe fruits of H. patulum has resulted in the isolation of two new pinane-type monoterpenoid glycosides 1-2, named patulumside E-F, and three new chain-shaped monoterpenoid glycosides 3-5, named patulumside G-H, J. Their structures were determined using extensive spectroscopic techniques, such as HR-ESI-MS, 1D and 2D NMR spectroscopy, and electronic circular dichroism (ECD) calculation. The anti-inflammatory activities of these compounds were evaluated in the LPS-induced RAW264.7 cells. This research represents the inaugural comprehensive phytochemical study of H. patulum, paving the way for further exploration of monoterpenoid glycosides.

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.

Six New Constituents from the Fruit of Hypericum patulum and Their Anti-Inflammatory Activity

Four new xanthone glucosides, 3-hydroxy-2-methoxyxanthone-4-O-β-D-glucopyranoside (1), 4,8-dihydroxy-2-methoxyxanthone-3-O-β-D-glucopyranoside (2), 2-methoxyxanthone-5-O-β-D-glucopyranoside (3), 4-hydroxy-2-methoxyxanthone-3-O-β-D-glucopyranoside (4), a new phenolic acid, 4,4'-dihydroxy-3,3'-imino-di-benzoic acid monomethyl ester (5), and a new isoquinoline, methyl 6-hydroxy-1-oxo-1,2,3,4-tetrahydroisoquinoline-4-carboxylate (6) were isolated from the fruit of Hypericum patulum. The structural elucidation of the isolated compounds was primarily based on HR-ESI-MS, UV, IR, 1D and 2D NMR. All compounds were evaluated for their inhibitory effect against LPS-induced NO production in RAW 264.7 cells. Compound 2, 3 exhibited moderate inhibitory activity against NO production.

Synthesis of natural products containing highly strained trans-fused bicyclo[3.3.0]octane: historical overview and future prospects

Owing to high strain energy, molecules with trans-fused bicyclo[3.3.0]octane ring systems are very difficult to synthesize, and there are very few approaches to access them. Recently, a number of natural products with such ring systems have been made by the synthetic community. However, there has been no review in this field before. This review provides a systematic and comprehensive discussion on the synthesis of natural products containing trans-fused bicyclo[3.3.0]octanes and the historical context of this work. The prospects for future research in this field are also discussed. Covering the literature before 2021, this review aims to offer a helpful reference for total synthesis of highly strained natural products containing trans-fused bicyclo[3.3.0]octane ring systems.

Characteristic metabolites of Hypericum plants: their chemical structures and biological activities

Plants belonging to the genus Hypericum (Hypericaceae) are recognized as an abundant source of natural products with interesting chemical structures and intriguing biological activities. In the course of our continuing study on constituents of Hypericum plants, aiming at searching natural product-based lead compounds for therapeutic agents, we have isolated more than 100 new characteristic metabolites classified as prenylated acylphloroglucinols, meroterpenes, ketides, dibenzo-1,4-dioxane derivatives, and xanthones including prenylated xanthones, phenylxanthones, and xanthonolignoids from 11 Hypericum plants and one Triadenum plant collected in Japan, China, and Uzbekistan or cultivated in Japan. This review summarizes their chemical structures and biological activities.

Studies on non-medicinal parts of plant materials: Triterpenes from the roots of Schisandra chinensis

Phytochemical study on a non-medicinal part of a plant material for herbal medicine, the roots of Schisandra chinensis, was conducted to isolate five new triterpenes, schinensins A-D (1-4) and 3-O-methylchangnanic acid (5), together with 21 known compounds including 10 triterpenes, one sterol, two sesquiterpenes, seven lignans, and one flavonoid. The structures of new triterpenes (1-5) were assigned on the basis of spectroscopic analyses aided with TDDFT ECD calculations. Schinensin A (1) was a dinortriterpene possessing 28-norschiartane skeleton, while schinensins B-D (2-4) were assigned as 3,4:9,10-disecocycloartane, 3,4-secocycloartane, and cycloartane triterpenes, respectively. In an evaluation of antiproliferative activities against human cancer cell lines, some triterpenes exhibited significant activities against human breast carcinoma MCF-7 cells as compared to the other cell lines (A549, HeLa, and RPMI8226).