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Greener Synthesis of Natural Products
Published in Ahindra Nag, Greener Synthesis of Organic Compounds, Drugs and Natural Products, 2022
Renata Kołodziejska, Renata Studzińska, Hanna Pawluk, Alina Woźniak
Aldolases have also found application in the asymmetrical synthesis of polyhydroxylated pyrrolizidine alkaloids, i.e., 7-epi-alexine, (+)-3-epi-australine, and (+)-australine.124 The synthesis of structurally related pyrrolizidines, which represent the stereoisomers of naturally occurring hyacinthacin A1 and A2 alkaloids, was performed using the step of coupling a proline derivative with DHAP catalyzed by 1-ramnulose-1-phosphate aldolase (RhuA) from E. coli. The reaction proceeded with excellent diastereoselectivity. Hyacinthacines A1 and A2 were isolated from the bulbs of Muscari armeniacum (Hyacinthaceae) and demonstrated to be good inhibitors against rat intestinal lactase, rat epididymis α-l-fucosidase, and amyloglucosidase from Arpergillus niger (Figure 14.34).125 1-fuculose-1-phosphate aldolase (FucA) as a biocatalyst is also successfully used in the production of some closely related pyrrolizidines (Figure 14.34).126
Marine algae–degrading enzymes and their applications in marine oligosaccharide preparation
Published in Antonio Trincone, Enzymatic Technologies for Marine Polysaccharides, 2019
Benwei Zhu, Limin Ning, Yun Sun, Zhong Yao
Fucoidanase activity was found in the digestive tract of the bivalve mollusk Pecten maximus (Daniel et al. 1999). Crude enzyme-catalyzed depolymerization of fucoidan from the brown algae Ascophyllum nodosum that yielded the products with molecular weights in the wide range of 3–25 kDa (Daniel et al. 1999). Enzyme preparation contained not only fucoidanase but also fucosidase. Subsequently P. maximus fucosidase was purified in homogeneous state. This enzyme was capable of cleaving nonsulfated fucose residues from oligosaccharides and was not specific to any type of linkages. The authors classified this enzyme as α-l-fucosidase (EC 3.2.1.51) (Berteau et al. 2002).
Comparison of Allergenic Potency of Four Batches of Cladosporium Herbarum for Preparation of Reference Standard
Published in Michael Muilenberg, Harriet Burge, Aerobiology, 2018
Hari M. Vijay, Maureen Burton, Gauri Muradia, N. Martin Young, Michael Corlett
The extracts contained large amounts of phosphatases, galactosidases, glucosidases, and β-glucosaminidase (Table 2). The enzyme profiles of the extracts were similar with the exception of oc-fucosidase which was not found in the extract A1. The extracts (including the pooled batch B) had similar isoelectric focusing patterns, i.e., 12 to 17 bands with pH values between 3.5 and 5.9, with the exception of extract A1 which had only 8 bands in the pH region 3.5–5.4 (Figure 1). The batch B had an additional band at pH 6.9 which, due to its unusual appearance, we are assuming, is an artifact.
Strategies for introducing sulfur atom in a sugar ring: synthesis of 5-thioaldopyranoses and their NMR data
Published in Journal of Sulfur Chemistry, 2019
A large variety of organo-sulfur compounds exhibiting a wide range of different properties are many in nature. Sugars analogs with sulfur in the ring are recognized to alter the physico-chemical properties and, thus, modulate the ‘information content’ of the modified sugar towards biochemical systems [6,7]. Therefore, thiosugars have gained much attention in terms of synthetic challenges and as potential bioactive inhibitors of glycosidases [8]. For example, 5-thio-d-xylopyranose has displayed good inhibitory activity against β-d-xylosidase [9]. Synthetic 5-thio-l-fucopyranose has attracted considerable attention for its inherent α-l-fucosidase inhibitory activities [10] whereas 5-thio-d-glucopyranose was found to inhibit specifically yeast α-glucosidase [11]. The significance of thiosugars as novel therapeutic prototypes in the treatment of a variety of pathological conditions, including cancer and infectious diseases has also been described [6,12]. As a result, these new trends will provide tremendous opportunities for the development of glycomimetics as new promising drugs.