Discovery of new triterpene glycosides from Dendrobium officinale with their α-glucosidase and α-amylase inhibitory activity

In this study, seven new pentacyclic triterpene glycosides, named dendrocinaosides A-G (1-7), and six known ones (8-13) were isolated from the whole plants of Dendrobium officinale. Their structures were determined by analyses of HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1-4, 8, and 9 potentially inhibited α-glucosidase and α-amylase activities with the IC50 values ranging from 31.3 ± 2.2 to 42.4 ± 2.5 μM for anti α-glucosidase and from 36.5 ± 1.8 to 56.4 ± 2.0 μM for anti α-amylase activities, respectively, which were lower than that of the positive control, acarbose, showing IC50 values of 47.1 ± 1.4 μM for anti α-glucosidase and 145.7 ± 2.2 μM for anti α-amylase.

Cryptobuchanosides A-G: seven previously undescribed triterpene glycosides from Cryptolepis buchananii R.Br. ex Roem. and Schult. with nitric oxide production inhibition activity

In this study, nine triterpene glycosides including seven previously undescribed compounds (1-7), were isolated from leaves of Cryptolepis buchananii R.Br. ex Roem. and Schult. using various chromatographic methods. The chemical structures of the compounds were elucidated to be 3-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (2), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyluncargenin C 28-O-β-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (3), 3-O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosylhederagenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (4), 3-O-β-D-glucopyranosylarjunolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (5), 3-O-β-D-glucopyranosyl-(1 → 2)-β- D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (6), 3-O-β-D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (7), asiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (8), and 3-O-β-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (9), through infrared, high-resolution electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectral analyses. The isolates inhibited nitric oxide production in lipopolysaccharide-activated RAW 264.7 cells, with half-maximal inhibitory concentration (IC50) values of 18.8-58.5 µM, compared to the positive control compound, dexamethasone, which exhibited an IC50 of 14.1 µM.

Four New Pentacyclic Triterpene Glycosides Isolated from the Fruits of Cryptolepis buchananii R.Br. ex Roem. & Schult and Their Inhibition of NO Production in LPS-activated RAW264.7 Cells

From the methanol extract of the Cryptolepis buchananii fruits, four undescribed pentacyclic triterpenene glycosides (1-4) and five known pentacyclic triterpenenes (5-9) were isolated. Their structures were determined to be uncargenin C 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (1), 3-O-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (2), 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (3), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (4), asiatic acid (5), 2α,3β,23-trihydroxyoleana-11,13(18)-dien-28-oic acid (6), arjunolic acid (7), 6β-hydroxyarjunolic acid (8), and actinidic acid (9) based on analyses of their HR-ESI-MS, 1D and 2D NMR spectra. All the isolates showed significantly NO production inhibition in LPS-activated RAW264.7 cells with the IC50 values ranging from 18.79 to 37.57 μM, compared to that of the positive control compound, dexamethasone, which showed IC50 value of 14.05 μM.

Response of plasma fibronectin to major body burn

The ability of macrophages of phagocytize particulate matter is largely dependent on fibronectin, a nonspecific opsonin found in plasma. Fibronectin depletion, resulting in reticuloendothelial system (RES) depression, occurs following a variety of physical insults. RES depression may contribute to postinjury sequelae such as respiratory distress syndrome and septicemia. Fibronectin concentration was measured in the plasma of sheep with chronic lung lymph fistulas subjected to controlled thermal injury. Fibronectin levels were significantly (p < 0.05) decreased at 4, 24, 48, and 72 hours following burning. Fibronectin concentration decreased in parallel with serum albumin concentration; serum globulin concentrations did not decrease. Fibronectin concentration had an inverse relationship to lung lymph flow, a reflection of pulmonary transvascular fluid filtration rate. The role of fibronectin in the pathogenesis of postinjury respiratory distress syndrome deserves further exploration.