Eight usnic acid derivatives, that is, usenamines A-F (1-6), usone (7), and isousone (8), together with the known (+)-usnic acid (9), were isolated from the lichen Usnea longissima. Their structures were elucidated using 1D and 2D NMR and MS data, and the absolute configurations of compounds 1 and 2 were defined by single-crystal X-ray diffraction analyses. Compounds 1, 2, and 8 showed inhibitory effects on the growth of human hepatoma HepG2 cells with IC50 values of 6.0-53.3 μM compared with methotrexate as the positive control, which had an IC50 value of 15.8 μM. Furthermore, 1 induced apoptosis of HepG2 cells in a dose-dependent manner at concentrations of 0-15.0 μM. The isolated compounds were also evaluated for their antifungal and antibacterial activities, with 7 and 8 exhibiting weak inhibitory effects on fungal Trichophyton rubrum spp. with an MIC value of 41.0 μM.

Genus Syringa, belonging to the Oleaceae family, consists of more than 40 plant species worldwide, of which 22 species, including 18 endemic species, are found in China. Most Syringa plants are used in making ornaments and traditional medicines, whereas some are employed for construction or economic use. Previous studies have shown that extracts of Syringa plants mainly contain iridoids, lignans, and phenylethanoids that have antitumor, antihypertensive, anti-oxidant, and anti-inflammatory activities. This study reviews phytochemical and pharmacological progress on Syringa in the recent 20 years and discusses the future research prospects to provide a reference in further promotion and application of the genus.Graphical AbstractPhytochemical and pharmacological progress on the genus Syringa

Abstract:The Bocconieae tribe, consisting of only the genera Macleaya and Bocconia, possesses significant economic and medicinal value and plays an important role in health management for people in developing countries. During the past decades, research on metabolites and relative pharmacology, including the isolation and identification of a variety of molecules, has shed light on the tribe. Among those molecules, isoquinoline alkaloids, and their antimicrobial, antifungal, and anti-inflammatory activities are especially noteworthy. This paper presents a comprehensive compilation of current research progress, with emphasis on the alkaloids and their distribution, phytochemical and pharmacological investigation, toxicity and side effects, related chemotaxonomy and future use prospects, and hopefully provides a valuable reference as an effort to promote further exploration and application of this tribe.

One new norlignan, namely noralashinol A (1), one known analogue (2), together with seven known lignans (3-9) were isolated from the stem barks of Syringa pinnatifolia. Their structures were elucidated extensively by spectroscopic methods, including mass spectrometry and 1D and 2D NMR spectroscopies. Compound 8 significantly inhibited NO production in LPS-induced BV-2 murine microglia cells with its IC50 value of 20.7 μM, compared to a positive control quercetin with its IC50 value of 15.3 μM.

As one of the biggest genera in Lauraceae, Neolitsea owns a great application potential in industrial and traditional medical fields. Modern phytochemical and biological investigations revealed its structural diversity and diverse activities. This review summarizes the most recent progress on this regards, hopefully to provide a reference for full use and development of the Neolitsea resource.