| 1. |
- Juang, Yu-Pu, et al.
(författare)
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Synthesis, distribution analysis and mechanism studies of N-acyl glucosamine-bearing oleanolic saponins
- 2020
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Ingår i: Bioorganic chemistry (Print). - : Elsevier. - 0045-2068. ; 99, s. 103835-
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Tidskriftsartikel (refereegranskat)abstract
- A series of N-acyl glucosamine-bearingtriterpenoidsaponins has been synthesized with cytotoxic activities evaluated against HL-60, PC-3, HCT-116, and CT-26 tumor cells. Saponins incorporated anoleanolic acid (OA) triterpenoidal core exhibited the highest cytotoxic activity. To study the influence of the lengths of acyl-carbon chain onN-position of glucosamine, cells were treated with28-propargylamides and then reacted with an azido-fluorogenic probe under CuAACclickreactions to visualize the intact distributions of these compounds by confocal microscopy and flow cytometry; it was found that cytotoxic-active compounds (30–32) located in the cytosol and inactivecompounds bearing longer carbon chains (33–35) were impenetrable across cell membranes.Our study demonstrated the defined lipophilic acyl-carbon chain length can precisely regulate thecytotoxic activityof saponins, which is useful for the future development of cytotoxic agents.Furthermore, using quantitative proteomics and immunolabeling,the mechanism ofcytotoxicity induced by the synthetic saponin after membrane penetration could be a result of activation of death receptor pathway and inhibition of PI3K/Akt/mTOR pathway.
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| 2. |
- Lin, Tzung-Sheng, et al.
(författare)
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Sulfation pattern of chondroitin sulfate in human osteoarthritis cartilages reveals a lower level of chondroitin-4-sulfate
- 2020
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 229
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Tidskriftsartikel (refereegranskat)abstract
- Chondroitin sulfates (CS) account for more than 80% of glycosaminoglycans of articular cartilage, which imparts its physiological functions. We quantified the absolute concentration of the CS components of the full thickness cartilages from the knees of patients with terminal-phase osteoarthritis. Osteochondrol biopsies were removed from the medial femoral condyle and lateral femoral condyle of sixty female patients receiving total knee arthroplasty, aged from 58 to 83 years old. We found that total CS concentrations and chondroitin-4-sulfate disaccharide were significantly lowered in osteoarthritic samples. Microstructure analysis indicated that while chondroitin-0-sulfate was equally distributed across different zones of the osteoarthritic cartilages, chondroitin-4-sulfate is significantly less in the deep zones. Down-regulation of sulfotransferases, the enzymes responsible for CS sulfation in the lesion site of cartilage were observed. Our study suggested chondroitin-4-sulfate down-regulation may be a diagnostic marker for degraded osteoarthritis cartilage, with potential implications in cartilage regeneration.
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