Lu Qu

A Review of Recent Research Progress on the Astragalus Genus

Astragalus L., is one of the largest genuses of flowering plants in the Leguminosae family. Roots of A. membranaceus Bge. var. mongholicus (Bge.) Hsiao, A. membranaceus (Fisch.) Bge. and its processed products are listed in the China Pharmacopeia for “qi deficiency” syndrome treatment. However, more and more researches on other species of Astragalus have been conducted recently. We summarize the recent researches of Astragalus species in phytochemistry and pharmacology. More than 200 constituents, including saponins and flavonoids, obtained from 46 species of Astragalus genus were collected for this article. In pharmacological studies, crude extracts of Astragalus, as well as isolated constituents showed anti-inflammatory, immunostimulant, antioxidative, anti-cancer, antidiabetic, cardioprotective, hepatoprotective, and antiviral activities. The goal of this article is to provide an overview of chemical and pharmacological studies on the Astragalus species over the last 10 years, which could be of value to new drug or food supplement research and development.

Rare Syringyl Acylated Flavonol Glycosides from the Aerial Parts of Leonurus japonicus Houtt.

Five new syringyl acylated flavonol glycosides, named leonurusoides A (1), B (2), C (3), D (4), and E (5), together with one known one 6 were obtained from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Compounds 1−6 showed triglyceride (TG) accumulation inhibitory effects in free fatty acid-induced HepG2 cells.

Anti-inflammatory steroids from the rhizomes of Dioscorea septemloba Thunb.

Seven new steroid glycosides, dioscorosides A1 (1), A2 (2), B1 (3), B2 (4), C1 (5), C2 (6), and D (7), together with 22 known ones (8-29) were isolated from the rhizomes of Dioscorea septemloba, their structures were elucidated by chemical and spectroscopic methods. All isolates were evaluated for in vitro anti-inflammatory potential using LPS-stimulated RAW 264.7 murine macrophages. Among them, spirostane glycosides 18 and 21-24 exhibited significant inhibition of nitrite production. Moreover, the structure-activity relationship was summarized.

New terpenoid glycosides obtained from Rosmarinus officinalis L. aerial parts

Five new terpenoid glycosides, named as officinoterpenosides A₁ (1), A₂ (2), B (3), C (4), and D (5), together with 11 known ones, (1S,4S,5S)-5-exo-hydrocamphor 5-O-β-D-glucopyranoside (6), isorosmanol (7), rosmanol (8), 7-methoxyrosmanol (9), epirosmanol (10), ursolic acid (11), micromeric acid (12), oleanolic acid (13), niga-ichigoside F₁ (14), glucosyl tormentate (15), and asteryunnanoside B (16), were obtained from the aerial parts of Rosmarinus officinalis L. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Among the new ones, 1 and 2, 3 and 4 are diterpenoid and triterpenoid glycosides, respectively; and 5 is a normonoterpenoid. For the known ones, 6 was isolated from the Rosmarinus genus first, and 15, 16 were obtained from this species for the first time.

Bioactive Constituents from the Aerial Parts of Lippia triphylla

Five new compounds, lippianosides A (1), B (2), C (3), D (4), and E (5), along with 26 (6–31) known ones were obtained from the 95% EtOH extract of Lippia triphylla (L. triphylla) aerial parts collected from Rwanda, Africa. Among the known compounds, 11 and 17–30 were isolated from the Lippia genus for the first time. In addition, 12, 13, and 16 were firstly obtained from this species. The structures of them were elucidated by chemical and spectroscopic methods. The antioxidant and triglyceride accumulation inhibition effects of the 31 compounds were examined in L6 cells and HepG2 cells, respectively.

Bioactive gentixanthone and gentichromone from the whole plants of Gentianella acuta (Michx.) Hulten.

Five new compounds, gentixanthones A1 (1), A2 (2), and gentichromones A1-A3 (3-5), together with thirteen known xanthones (6-18) were obtained from the whole plants of Gentianella acuta (Michx.) Hulten. Their structures were elucidated by chemical and spectroscopic methods. Among them, compounds 6, 8, 13, 14, and 17 were obtained from Gentianella genus firstly, and 7, 12, 15, 16, and 18 were isolated from this plant for the first time. Meanwhile, inhibitory effects of 1-18 on motility of mouse isolated intestine tissue were determined. As results, xanthones 1, 2, 6, 7, 9, 10 and 14 were found to have significant reduce effect on intestine contraction tension, and structure-activity relationship was discussed.

Bioactive constituents from the rhizomes of Dioscorea septemloba Thunb

Eight new compounds, dioscorosides G (1), H1 (2), H2 (3), dioscorol B (4), dioscorosides I (5), J (6), K1 (7), and K2 (8), together with twelve known ones (9-20) were obtained from the rhizomes of Dioscorea septemloba. Their structures were elucidated by chemical and spectroscopic methods. Among the known isolates, 12-14, 18, and 20 were isolated from the Dioscoreae genus for the first time. While, 9-11, 15, and 16 were firstly obtained from the plant. Moreover, all the isolates were evaluated for in vitro anti-inflammatory potential using LPS-stimulated RAW 264.7 murine macrophages, and compounds 7, 11, 15, and 16 were found to display significant inhibition of nitrite production.

Spirostane-Type Saponins Obtained from Yucca schidigera

It is well known that spirostane-type saponins show various bioactivities. In our on-going program of screening these kinds of constituents from natural products, Yucca schidigera was found to be rich in them, and nine new spirostanol saponins, Yucca spirostanosides A1 (1), A2 (2), B1 (3), B2 (4), B3 (5), C1 (6), C2 (7), C3 (8), and D1 (9), together with five known ones (10–14) were isolated from the plant. Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and MS spectra, and comparing with published data.

Chemical and Biological Research on Herbal Medicines Rich in Xanthones

Xanthones, as some of the most active components and widely distributed in various herb medicines, have drawn more and more attention in recent years. So far, 168 species of herbal plants belong to 58 genera, 24 families have been reported to contain xanthones. Among them, Calophyllum, Cratoxylum, Cudrania, Garcinia, Gentiana, Hypericum and Swertia genera are plant resources with great development prospect. This paper summarizes the plant resources, bioactivity and the structure-activity relationships (SARs) of xanthones from references published over the last few decades, which may be useful for new drug research and development on xanthones.

Bioactive Constituents Obtained from the Seeds of Lepidium apetalum Willd

Three new compounds, apetalumosides C1 (1), D (2), and 1-thio-β-d-glucopyranosyl(1→1)-1-thio-α-d-glucopyranoside (3), together with twenty-two known ones (4–25) were obtained from the seeds of Lepidium apetalum Willd. Among the known isolates, 5–8, 10–13, 16–20, and 25 were obtained from the genus for the first time; 4, 14, 15, and 21–24 were isolated from the species for the first time. Meanwhile, the NMR data of 16 was first reported here. Their structures were determined by means of chemical and spectroscopic methods. On the other hand, their inhibitory effects on sodium oleate-induced triglyceride (TG) overloading in HepG2 cells were evaluated. As a result, two new compounds (1 and 2), together with known isolates 7–11, 13, 14, 16–18, 20, 21, and 25 possessed significant inhibitory effects in the cells.