Publications by authors named "Han-Tao Zhou"

Amusurgus (Usgmona) excavatus Liu, Shi et Zhou, sp. nov. (China, Fujian) is described and illustrated with the male genitalia.

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  • This study investigated how heat affects the enzyme β-glucosidase from Hypocrea orientalis, revealing that its inactivation is irreversible and follows a first-order reaction.
  • It found that certain substrates can effectively protect the enzyme from thermal damage, especially glucose at a concentration of 20mM, which kept the enzyme's activity intact up to 70°C.
  • Additionally, glucose not only reduces the inactivation rate of the enzyme but also stabilizes its structure against heat, as shown through intrinsic fluorescence and docking simulations.
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In the present study the structure of proanthocyanidins from Polyalthia longifolia leaves was characterized with (13)C nuclear magnetic resonance, high performance liquid chromatography electrospray ionization mass spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses. The results showed that the proanthocyanidins were mixture of homopolymers of B-type procyanidins with degree of polymerization up to 14-mer. Furthermore, the antioxidant activity of the proanthocyanidins was studied through 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free-radical scavenging activities, and ferric reducing/antioxidant power assays.

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  • - Proanthocyanidins were extracted from the fruit stone of Chinese hawthorn, and their structures were analyzed using advanced mass spectrometry techniques like MALDI-TOF MS and HPLC-ESI-MS.
  • - The compounds were found to be complex mixtures of different polymers with varying structural characteristics, including differences in their monomer units and linkage types.
  • - Testing showed that these proanthocyanidins can effectively inhibit tyrosinase activity (an enzyme related to pigmentation) and exhibit significant antioxidant properties, suggesting potential applications in food, agriculture, pharmaceuticals, and cosmetics.
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In this research, the conditions for extraction of phenolics from leaves of Ficus virens were optimized using response surface methodology (RSM). The extraction abilities of phenolics (EAP) and flavonoids (EAF), the 2,2-diphenyl-1-pierylhydrazyl (DPPH) free-radical scavenging potential, and the ferric reducing/antioxidant power (FRAP) were used as quality indicators. The results of single-factor experiments showed that temperature, ethanol concentration, extraction time, and the number of extraction cycles were the main influencing variables, and these provided key information for the central composite design.

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The inhibitory kinetics of furfuryl alcohol, furfural and furoic acid on mushroom tyrosinase have been investigated. The results showed that these furan compounds were reversible inhibitors of the enzyme. Furthermore, furfuryl alcohol and furfural were found to be mixed-type inhibitors while furoic acid is uncompetitive inhibitor.

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The effects of betaine on prawn beta-N-acetyl-D-glucosaminidase (NAGase) activity for the hydrolysis of p-nitrophenyl-N-acetyl- beta-D-glucosaminide (pNP-NAG) have been studied. The results showed that appropriate concentrations of betaine could lead to reversible inhibition against NAGase, and the IC(50) value was estimated to be 15.00 +/- 0.

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RNAs of the leaves in Avicennia marina, which cultured in 50@1000 and 0@1000 salinity condition respectively, were isolated for mRNA differential display analysis. Screened by OligodT12 GC and eight 10-oligonucleotide arbitrary primers, differential cDNA fragments-csrg1(600 bp), csrg2(550 bp), csrg3(480 bp), only appeared in the leaves of Avicennia marina cultured in 50@1000 salinity condition. After detected by RNA dot hybridization, only csrg1 appeared the difference between the RNAs of the leaves in Avicennia marina cultured in 50@1000 and 0@1000 salinity condition respectively, and csrg1 was confirmed as the salt-tolerant cDNA.

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