1986-15-8Relevant academic research and scientific papers
Oleanane-type triterpene saponins from Aralia armata leaves and their cytotoxic activity
Yen, Pham Hai,Chuong, Nguyen Th? Hong,Lien, Giang Thi Kim,Cuc, Nguyen Thi,Nhiem, Nguyen Xuan,Thanh, Nguyen Thi Viet,Tai, Bui Huu,Seo, Yohan,Namkung, Wan,Park, SeonJu,Kim, Seung Hyun,Minh, Chau Van,Kiem, Phan Van
, p. 142 - 149 (2021)
Two new, aramatosides A and B (1 and 2), together with seven known oleanane-type triterpene saponins (3–9) were isolated from the leaves of Aralia armata. Their structures were determined by combination of HR-ESI-MS, 1 D and 2 D NMR spectral data as well as comparison with the previous literature. Compounds 6–9 exhibited cytotoxic effects towards three human cancer cell lines (HT29, A2058, and A549) with IC50 values ranging from 2.01 ± 0.17 to 18.8 ± 1.17 μM. Especially, compound 7 (narcissiflorin) showed significant cytotoxic activity against HT29 and A549 cell lines with IC50 values of 2.02 ± 1.65 and 2.01 ± 0.17 μM, respectively, which are smaller than those of positive control irinotecan hydrochloride (IC50 values of 10.3 ± 1.32 and 9.89 ± 0.19 μM).
Catalytic wet air oxidation of D-glucose by perovskite type oxides (Fe, Co, Mn) for the synthesis of value-added chemicals
Geobaldo, Francesco,Pirone, Raffaele,Russo, Nunzio,Scelfo, Simone
, (2022/03/15)
The conversion of common biomasses derived, as D-glucose, into value-added chemicals has received highest attention in the last few years. Among all processes, the catalytic wet air oxidation (CWAO) of derived biomasses using noble metal-based heterogeneo
Quantitative Determination of Pt- Catalyzed d -Glucose Oxidation Products Using 2D NMR
Armstrong,Hirayama,Knight,Hutchings
, p. 325 - 335 (2019/01/04)
Quantitative correlative 1H-13C NMR has long been discussed as a potential method for quantifying the components of complex reaction mixtures. Here, we show that quantitative HMBC NMR can be applied to understand the complexity of the catalytic oxidation of glucose to glucaric acid, which is a promising bio-derived precursor to adipic acid, under aqueous aerobic conditions. It is shown through 2D NMR analysis that the product streams of this increasingly studied reaction contain lactone and dilactone derivatives of acid products, including glucaric acid, which are not observable/quantifiable using traditional chromatographic techniques. At 98% glucose conversion, total C6 lactone yield reaches 44%. Furthermore, a study of catalyst stability shows that all Pt catalysts undergo product-mediated chemical leaching. Through catalyst development studies, it is shown that sequestration of leached Pt can be achieved through use of carbon supports.
Characterization of ulvan extracts to assess the effect of different steps in the extraction procedure
Costa, Carina,Alves, Anabela,Pinto, Paula R.,Sousa, Rui A.,Borges Da Silva, Eduardo A.,Reis, Rui L.,Rodrigues, Alírio E.
experimental part, p. 537 - 546 (2012/06/15)
An effective application development of the polysaccharide ulvan requires a comprehensive knowledge about the influence of the extraction process on composition of the extracts and in ulvan itself. In this context, the two main objectives of the present work are (1) the establishment of an efficient extraction process for ulvan and (2) development of an accurate characterization methodology to evaluate the extract composition and ulvan content. Three ulvan-rich extracts obtained by different schemes of extraction were studied. The methodology for the analysis was improved and a detailed analysis of extracted ulvan was provided. The polysaccharide is rich in ulvanobiuronic acid 3-sulfate type A [→4)-β-d-GlcAp-(1 → 4)-α-l-Rhap 3S-(1→], with minor amounts of ulvanobiuronic acid 3-sulfate type B [→4)-α-l-IdoAp-(1 → 4)-α-l-Rhap 3S-(1→]. The extract with the higher degree of purification is a high molecular weight polysaccharide (790 kDa) composed of rhamnose (22.4%), glucuronic acid (22.5%), xylose (3.7%), iduronic acid (3.1%) and glucose (1.0%). It is highly sulfated (32.2%) and contains 1.3% of proteins and 10.3% of inorganic material. Applying simple extraction scheme it was possible to obtain an extract from green algae with high content of ulvan without affecting the overall chemical structure of the polysaccharide.
THE SELECTIVE OXIDATION OF ALDOSES AND ALDONIC ACIDS TO 2-KETOALDONIC ACIDS WITH LEAD-MODIFIED PLATINUM-ON-CARBON CATALYSTS
Smits, Pierre C. C.,Kuster, Ben F. M.,Wiele, Kees van der,Baan, Hessel S. van der
, p. 227 - 236 (2007/10/02)
Aldoses and aldonic acids have been oxidised with oxygen and air at 55 deg in water, using Pt/C catalysts.After oxidation of the reducing group, if available, the primary hydroxyl group is preferentially oxidised using an unmodified catalyst.Addition of a lead(II) salt changes the preference dramatically towards oxidation at the position α to the carboxyl group.Provided that oxygen transfer to the liquid phase is carefully controlled in order to prevent deactivation of the catalyst, 2-ketoaldonic acids can be prepared in high yields.
