New polyoxypregnane glycosides from Aspidopterys obcordata vines with antitumor activity

Comparative Study of the Structural Characteristics and Bioactivity of Polysaccharides Extracted from Aspidopterys obcordata Hemsl. Using Different Solvents

The polysaccharides extracted from Aspidopterys obcordata are thought to have anti-urolithiasis activity in Drosophila kidney stones. This study aimed to assess the effects of different extraction solvents on the yield, chemical composition, and bioactivity of polysaccharides from A. obcordata. A. obcordata polysaccharides were extracted by using four solutions: hot water, HCl solution, NaOH solution, and 0.1 M NaCl. The results revealed that the extraction solvents significantly influenced the extraction yields, molecular weight distribution, monosaccharide compositions, preliminary structural characteristics, and microstructures of polysaccharides. The NaOH solution's extraction yield was significantly higher than the other extraction methods. Vitro antioxidant activity assays revealed that the NaOH solution extracted exhibited superior scavenging abilities towards DPPH and ABTS radicals and higher FRAP values than other polysaccharides. The vitro assays conducted for calcium oxalate crystallization demonstrated that four polysaccharides exhibited inhibitory effects on the nucleation and aggregation of calcium oxalate crystals, impeded calcium oxalate monohydrate growth, and induced calcium oxalate dihydrate formation. The NaOH solution extracted exhibited the most pronounced inhibition of calcium oxalate crystal nucleation, while the hot water extracted demonstrated the most significant suppression of calcium oxalate crystal aggregation. Therefore, it can be inferred that polysaccharides extracted with NaOH solution exhibited significant potential as a viable approach for extracting polysaccharides from stems due to their superior yield and the remarkable bioactivity of the resulting products.

Four Meroterpenoids with Novel Aminoglycoside Moiety from the Basidiomycete Clitocybe clavipes with Cytotoxic Activity

Four new meroterpenoids, Clavilactone M-P, possessing novel aminoglycoside moiety (1-4) and a 10-membered carbocycle fused with an α,β-epoxy-γ-lactone, were isolated from Clitocybe clavipes, a basidiomycete. Their structures with absolute configurations were determined by extensive analysis of their spectroscopic data, and the ECD method. All the isolated compounds (1-4) were evaluated for their antitumor activity against three human cancer cell lines using the MTT assay. Compound 1 and 2 exhibited a significant suppression of cell viability in the Hela (IC₅₀ = 22.8 and 19.7 μM) cell line.

C21 steroids from the roots of Marsdenia tenacissima

A phytochemical investigation of the dichloromethane soluble fraction of the ethanolic extract obtained from the roots of Marsdenia tenacissima led to the discovery of the sixteen undescribed pregnane C₂₁ steroids (1-16) and isolation of eleven known C₂₁ steroidal analogues (17-27). Their chemical structures were elucidated by one- and two-dimensional nuclear magnetic resonance spectroscopy and, high resolution-electrospray ionization mass spectrometry and their absolute configurations were determined using electronic circular dichroism or single-crystal X-ray diffraction. The in vitro anti-proliferative effects of 1-16 were evaluated against HepG2 (human hepatocellular cancer), A549 (lung cancer), and MCF-7 (human breast cancer) cell lines. Even though some of them showed moderate cytotoxic activities, marsectohexol derivative 12 exhibited significant cytotoxicity against A549 cells with an IC₅₀ value of 5.2 μM.

Five New Polyoxypregnane Glycosides from the Vines of Aspidopterysobcordata and Their Antinephrolithiasis Activity

From the dried vines of Aspidopterys obcordata Hemsl, five new polyoxypregnane glycosides, named obcordatas J–N (1–5), were obtained. Their structures were fully elucidated and characterized by HRESIMS and extensive spectroscopic data. In addition, all of the new compounds were screened for their antinephrolithiasis activity in vitro. The results showed that compounds 1–3 have prominent protective effects on calcium oxalate crystal-induced human kidney 2 (HK-2) cells, with EC₅₀ values ranging from 6.72 to 14.00 μM, which is consistent with the application value of A. obcordata in folk medicine for kidney stones.

Complete plastome sequence of Aspidopterys obcordata (Malpighiaceae), a traditional Dai medicinal plant from Xishuangbanna, Yunnan, China

We reported the first complete plastid genome of Aspidopterys (Malpighiaceae) in this study. The complete plastome of Aspidopterys obcordata is 160,453 bp in length with a base composition of A (31.4%), G (18.5%), C (18.2%), and T (32.0%). Structurally, the genome contains two short inverted repeats (26,905 bp for each), which are separated by a large single copy region (88,491 bp) and a small single copy region (18,152 bp). The plastome contained 113 unique genes, including 79 protein-coding genes, 30 transfer RNAs, and 4 ribosomal RNAs. Phylogenetic analyses showed that A. obcordata was sister to Bunchosia argentea in the monophyletic Malpighiaceae. This study provided a high-quality plastome sequence for future studies in Aspidopterys, as well as Malpighiaceae.

Aspidoptoids A-D: Four New Diterpenoids from Aspidopterys obcordata Vine

Four new diterpenoids, named aspidoptoids A–D (1–4), together with two known analogues (5–6) were isolated from Aspidopterys obcordata vine. Aspidoptoids A–B (1–2) are the first examples of phenylethylene-bearing 20-nor-diterpenoids of which aspidoptoid B (2) possesses a rare 3,10-oxybridge. Their structures and absolute configuration were determined by extensive spectroscopic analyses (IR, HRESIMS, 1D and 2D NMR) and electronic circular dichroism (ECD) calculation. In addition, all the isolates were evaluated for their cytotoxic activities and inhibitory effects on the nitric oxide (NO) production.

Efficacy of Obcordata A from Aspidopterys obcordata on Kidney Stones by Inhibiting NOX4 Expression

Obcordata A (OA) is a polyoxypregnane glycoside derived from the Dai medicine Aspidopterys obcordata vines. This study aims to investigate the efficacy of OA on renal tubular epithelial cells exposed to calcium oxalate crystals. We incubated renal tubular cells with 28 μg·cm2 calcium oxalate crystals for 24 h with and without OA, GKT137831, phorbol-12-myristate-13-acetate (PMA), and tocopherol. The MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, microscopic examination, flow cytometry, and immunofluorescence staining revealed that calcium oxalate crystals decreased cell viability and elevated reactive oxygen species (ROS) levels. OA, GKT137831, and tocopherol protected cells and decreased ROS levels. However, OA did not exhibit direct DPPH scavenging ability. In addition, immunoblotting illustrated that OA inhibited the NOX4 (nicotinamide adenine dinucleotide phosphate oxidases 4) expression and downregulated the protein expression in the NOX4/ROS/p38 MAPK (p38 mitogen-activated protein kinase) pathway. The findings suggest that the cytoprotective and antioxidant effects of OA can be blocked by the NOX4 agonist PMA. In conclusion, OA could be used as a NOX4 inhibitor to prevent kidney stones.