Jun-Li Yang

Phytochemicals and Biological Activities of Pulicaria Species

Ligularia, an important genus of the Compositae family, has captured the interest of natural product chemists for years. Phytochemical investigations on the title genus have led to isolation of hundreds of secondary metabolites with various skeletons. Herein, we summarized the chemical constituents of this genus and their biological activities over the past few decades. Open image in new window

Optimization of ultrasonic cell grinder extraction of anthocyanins from blueberry using response surface methodology

Ultrasonic cell grinder extraction (UCGE), using water as the solvent, was firstly applied to extract anthocyanins from blueberry. Extraction yield was related with four variables, including ratio of solution to solid, extraction power, buffer time, and extraction time. On the basis of response surface methodology (RSM), the optimal conditions were determined to be the ratio of solution to solid as 25:1(mL/g), the extraction power as 1500W, the buffer time as 3.0s, and the extraction time as 40min. The experimental yield of anthocyanins using UCGE was 2.89mg/g higher than that of conventional ultrasound-assisted extraction (CUAE). This study indicated that UCGE was an innovative, efficient, and environment friendly method in ultrasonic extraction fields, and had a potential to effectively extract other bioactive constituents.

Phytochemicals and biological activities of Ligularia species

Ligularia, an important genus of the Compositae family, has captured the interest of natural product chemists for years. Phytochemical investigations on the title genus have led to isolation of hundreds of secondary metabolites with various skeletons. Herein, we summarized the chemical constituents of this genus and their biological activities over the past few decades.

Limonoids and Quinoline Alkaloids from Dictamnus dasycarpus

Phytochemical investigation on Dictamnus dasycarpus (Rutaceae) has led to the isolation of four new secondary metabolites (2, 6, 9, and 10) along with twelve known phytochemicals (1, 3- 5, 7, 8, 11-16). Compound 4 was isolated as a natural product for the first time. The structures of compounds 1-16 were elucidated by extensive spectroscopic analyses and comparison with previously reported spectroscopic data. The structures of 8 and 13 were further confirmed based on X-ray data analyses. The absolute configuration of compounds 8-12 were studied based on the CD spectra analyses.

Cycloartane-type triterpenoids and sesquiterpenoids from the resinous exudates of Commiphora opobalsamum

Cycloartane-type triterpenoids (1-3), seven sesquiterpenoids (7-13), and five previously reported secondary metabolites, including three cycloartane-type triterpenoids (4-6) and two sesquiterpenoids (14 and 15), were isolated from the resinous exudates of Commiphora opobalsamum. Their structures were elucidated by extensive spectroscopic analysis, including UV, IR, NMR, and MS, and comparison with literature data. The structures of 1, 3, and 7 were confirmed by single-crystal X-ray diffraction analysis. The absolute configuration of 1 was interpreted by the incorporation of CHCl(3) (crystallization solvent) in the crystal and that of 10 was determined by the CD exciton chirality method. Compound 12 represents the first example of a 12-norcadinane-type sesquiterpenoid. Furthermore, compounds 1, 3, 7, and 10-14 were evaluated for cytotoxicity against HeLa and HepG2 cell lines.

Structurally Diverse Terpenoids from the Rhizomes of Cyperus rotundus L.

An extract of the rhizomes of Cyperus rotundus L. afforded two new sesquiterpenoids (2 and 3) with rearranged secoeudesmane and germacrane skeletons, and a new 9,10-seco-cycloartane triterpenoid (9), as well as seven previously reported terpenoids, including a monoterpenoid (1), five sesquiterpenoids (4-8) with guaiane, patchoulane, and eudesmane skeletons, and a 3,4- seco-dammarane nortriterpenoid (10). The structures of 1-10 were elucidated by extensive spectroscopic methods and comparison with the literature data. The structures of 2 and 6 were confirmed by single-crystal X-ray diffraction analysis. The carbon skeleton of 2 is the third example reported thus far of such a skeleton and the 9,10-seco-cycloartane framework of 9 has rarely been found from a natural source. Compound 7 was a new natural product and compounds 1-5 and 7-10 were discovered from the genus Cyperus for the first time. This study may provide some useful information for the chemotaxonomy for the plant Cyperus rotundus.

Sesquiterpenoids from Inula britannica.

Phytochemical investigation of the flowers of Inula britannica led to the isolation of nineteen sesquiterpenoids (1- 19), including britanlins E-J ( 2, 3, 5, 8, 13, and 14, respectively) and known sesquiterpenoids (1, 4, 6, 7, 9- 12, and 15- 19). The structures of these isolates were elucidated by detailed spectroscopic analyses and comparison to the previously reported spectroscopic data. The absolute configurations of compounds 12, 15, 17, and 19 were determined by X-ray single crystal diffraction analyses and chemical transformations.

Sesquiterpenoids and other constituents from the flower buds of Tussilago farfara

One new norsesquiterpenoid, namely tussfarfarin A (1), and four new artifacts resulting from extraction procedure, namely tussfarfarin B (2), 6-(1-ethoxyethyl)-2,2-dimethylchroman-4-ol (3), 5-ethoxymethyl-1H-pyrrole-2-carbaldehyde (4), and 3β-hydroxy-7α-ethoxy-24β-ethylcholest-5-ene (5), along with 18 known compounds, were isolated from the flower buds of Tussilago farfara. Their structures were elucidated by extensive spectroscopic analysis.

Efficient synthesis of camptothecin propargylamine derivatives in water catalyzed by macroporous adsorption resin-supported gold nanoparticles

In this work, for the first time, we report an efficient, simple strategy for synthesizing active camptothecin (CPT) derivatives in water. A novel macroporous adsorption resin-supported gold nanoparticle (MAR-AuNP) was first in situ prepared in water. The resulting MAR-AuNPs swell in water and were applied not only as an efficient adsorbent for hydrophobic CPT molecules, but also as a catalyst for the Mannich reaction of CPT, formaldehyde and amines with water as a solvent. A series of novel CPT propargylamine derivatives were successfully obtained with high yields by virtue of such a strategy. Moreover, the resulting CPT propargylamine derivatives exhibited excellent cytotoxicity against two different tumor cell lines. This novel and efficient strategy, avoiding the use of toxic solvents, represents a promising green route for drug discovery from natural products and shows great potential in the green pharmaceutical industry.

Isolation and Identification of Saponins from the Natural Pasturage Asterothamnus centrali-asiaticus Employing Preparative Two-Dimensional Reversed-Phase Liquid Chromatography/Hydrophilic Interaction Chromatography

Asterothamnus centrali-asiaticus, a kind of characteristic shrub abundant in grassland and desert areas, has been used as forage fodder for camels and goats in Central Asia, and this plant also plays a critical role in the maintenance of desert grassland ecosystems as a result of its tolerance to poor soils and sand burial. However, its chemical composition has been rarely reported. In this study, phytochemical investigation of this pasturage was performed and three new triterpenoid saponins (1-3) were isolated together with nine known triterpenoid saponins (4-12) using preparative two-dimensional reversed-phase liquid chromatography/hydrophilic interaction chromatography (2D RPLC/HILIC). Their structures were elucidated via diverse spectroscopic analyses, including infrared (IR) spectrometry, high-resolution electrospray ionization mass spectrometry (HR-ESIMS), and one-dimensional (1D) and 2D nuclear magnetic resonance (NMR). All isolated triterpenoid saponins (1-12) were reported from this genus for the first time, and they were further evaluated for their cytotoxicity against four cancer cell lines (A549, HepG2, MGC-803, and MFC), which indicated that compound 11 showed potent cytotoxicity against the HepG2 cell line, with an IC50 value of 6.85 μg/mL.