Continuous flow biocatalysis: synthesis of purine nucleoside esters catalyzed by lipase TL IM from Thermomyces lanuginosus.

Purine nucleoside ester is one of the derivatives of purine nucleoside, which has antiviral and anticancer activities. In this work, a continuous flow synthesis of purine nucleoside esters catalyzed by lipase TL IM from Thermomyces lanuginosus was successfully achieved. Various parameters including solvent, reaction temperature, reaction time/flow rate and substrate ratio were investigated. The best yields were obtained with a continuous flow microreactor for 35 min at 50 °C with the substrate ratio of 1 : 5 (nucleosides to vinyl esters) in the solvent of tert-amyl alcohol. 12 products were efficiently synthesized with yields of 78-93%. Here we reported for the first time the use of lipase TL IM from Thermomyces lanuginosus in the synthesis of purine nucleoside esters. The significant advantages of this methodology are a green solvent and mild conditions, a simple work-up procedure and the highly reusable biocatalyst. This research provides a new technique for rapid synthesis of anticancer and antiviral nucleoside drugs and is helpful for further screening of drug activity.

Correction: Lonicera japonica Thunb. as a promising antibacterial agent for Bacillus cereus ATCC14579 based on network pharmacology, metabolomics, and in vitro experiments.

[This corrects the article DOI: 10.1039/D3RA00802A.].

Development of a green, concise synthesis of nicotinamide derivatives catalysed by Novozym® 435 from Candida antarctica in sustainable continuous-flow microreactors.

An increasing number of studies have shown that many nicotinamide derivatives exhibited extensive biological activities, such as anti-inflammatory and antitumor activity. In this paper, a green, concise synthesis of nicotinamide derivatives in sustainable continuous-flow microreactors catalysed by Novozym® 435 from Candida antarctica has been developed. Application of an easily obtainable and reusable lipase in the synthesis of nicotinamide derivatives from methyl nicotinate and amines/benzylamines reacted for 35 min at 50 °C led to high product yields (81.6-88.5%). Environmentally friendly tert-amyl alcohol was applied as a reaction medium. Substantially shorter reaction times as well as a significant increase in the product yield were obtained as compared to the batch process. This innovative approach provides a promising green, efficient and rapid synthesis strategy for pharmaceutical synthesis and further activity research of novel nicotinamide derivatives.

Lonicera japonica Thunb. as a promising antibacterial agent for Bacillus cereus ATCC14579 based on network pharmacology, metabolomics, and in vitro experiments.

Lonicera japonica Thunb. has attracted much attention for its treatment of bacterial and viral infectious diseases, while its active ingredients and potential mechanisms of action have not been fully elucidated. Here, we combined metabolomics, and network pharmacology to explore the molecular mechanism of Bacillus cereus ATCC14579 inhibition by Lonicera japonica Thunb. In vitro inhibition experiments showed that the Lonicera japonica Thunb.'s water extracts, ethanolic extract, luteolin, quercetin, and kaempferol strongly inhibited Bacillus cereus ATCC14579. In contrast, chlorogenic acid and macranthoidin B had no inhibitory effect on Bacillus cereus ATCC14579. Meanwhile, the minimum inhibitory concentrations of luteolin, quercetin, and kaempferol against Bacillus cereus ATCC14579 were 15.625 µg mL-1, 31.25 µg mL-1, and 15.625 µg mL-1. Based on the previous experimental basis, the metabolomic analysis showed the presence of 16 active ingredients in Lonicera japonica Thunb.'s water extracts and ethanol extracts, with differences in the luteolin, quercetin, and kaempferol contents between the water extracts and ethanol extracts. Network pharmacology studies indicated that fabZ, tig, glmU, secA, deoD, nagB, pgi, rpmB, recA, and upp were potential key targets. Active ingredients of Lonicera japonica Thunb. may exert their inhibitory effects by inhibiting ribosome assembly, the peptidoglycan biosynthesis process, and the phospholipid biosynthesis process of Bacillus cereus ATCC14579. An alkaline phosphatase activity assay, peptidoglycan concentration assay, and protein concentration assay showed that luteolin, quercetin, and kaempferol disrupted the Bacillus cereus ATCC14579 cell wall and cell membrane integrity. Transmission electron microscopy results showed significant changes in the morphology and ultrastructure of the cell wall and cell membrane of Bacillus cereus ATCC14579, further confirming the disruption of the cell wall and cell membrane integrity of Bacillus cereus ATCC14579 by luteolin, quercetin, and kaempferol. In conclusion, Lonicera japonica Thunb. can be used as a potential antibacterial agent for Bacillus cereus ATCC14579, which may exert its antibacterial activity by destroying the integrity of the cell wall and membrane.

A sustainable innovation for the tandem synthesis of sugar-containing coumarin derivatives catalyzed by lipozyme TL IM from Thermomyces lanuginosus in continuous-flow microreactors.

We developed an efficient and environmentally friendly two-step tandem methodology for the synthesis of sugar-containing coumarin derivatives catalyzed by lipozyme TL IM from Thermomyces lanuginosus in continuous-flow microreactors. Compared to those observed for other methods, the salient features of this work including green reaction conditions, short residence time (50 min), and catalysts are more readily available and the biocatalysis reaction process is efficient and easy to control. This two-step tandem synthesis of coumarin derivatives using the continuous-flow technology is a proof of concept that opens the use of enzymatic microreactors in coumarin derivative biotransformations.

Expression significance and potential mechanism of hypoxia-inducible factor 1 alpha in patients with myelodysplastic syndromes.

OBJECTIVE: To investigate the expression level and potential mechanism of hypoxia-inducible factor 1 alpha (HIF-1α) in patients with myelodysplastic syndromes (MDS). METHODS: Immunohistochemistry (IHC) techniques were used to examine the protein expression of HIF-1α in paraffin-embedded myeloid tissues from 82 patients with MDS and 33 controls (patients with lymphoma that is not invading myeloid tissues). In addition, the associations between the protein expression of HIF-1α and clinical parameters were examined. To further investigate the significance of HIF-1α expression in MDS patients, the researchers not only extracted the data about HIF-1α expression from MDS-related microarrays but also analyzed the correlation between the level of HIF-1α expression and MDS. The microRNA (miRNA) targeting HIF-1α was predicted and verified with a dual luciferase experiment. RESULTS: Immunohistochemistry revealed that the positive expression rate of HIF-1α in the bone marrow of patients with MDS was 90.24%. This rate was remarkably higher than that of the controls (72.73%) and was statistically significant (P < .05), which indicated that HIF-1α was upregulated in the myeloid tissues of MDS patients. For the GSE2779, GSE18366, GSE41130, and GSE61853 microarrays, the average expression of HIF-1α in MDS patients was higher than in the controls. Particularly for the GSE18366 microarray, HIF-1α expression was considerably higher in MDS patients than in the controls (P < .05). It was predicted that miR-93-5p had a site for binding with HIF-1α, and a dual luciferase experiment confirmed that miR-93-5p could bind with HIF-1α. CONCLUSION: The upregulated expression of HIF-1α was examined in the myeloid tissues of MDS patients. The presence of HIF-1α (+) suggested an unsatisfactory prognosis for patients, which could assist in the diagnosis of MDS. In addition, miR-93-5p could bind to HIF-1α by targeting, showing its potential to be the target of HIF-1α in MDS.

The convenient Michael addition of imidazoles to acrylates catalyzed by Lipozyme TL IM from Thermomyces lanuginosus in a continuous flow microreactor.

A fast and green protocol for the Michael addition of imidazoles to acrylates catalyzed by Lipozyme TL IM from Thermomyces lanuginosus in a continuous flow microreactor was developed. In contrast with existing methods, this method is simple (35 min), uses mild reaction conditions (45 °C) and is environmentally friendly. This enzymatic Michael addition performed in continuous flow microreactors is an innovation that may open up the use of enzymatic microreactors in imidazole analogue biotransformations.

Enzymatic synthesis of nucleoside analogues from uridines and vinyl esters in a continuous-flow microreactor.

We achieved the effective controllable regioselective acylation of the primary hydroxyl group of uridine derivatives catalyzed by Lipase TL IM from Thermomyces lanuginosus with excellent conversion and regioselectivity. Various reaction parameters were studied. These regioselective acylations performed in continuous flow microreactors are a proof-of-concept opening the use of enzymatic microreactors in uridine derivative biotransformations.