Publications by authors named "Wan Wen Zhu"

Phosphatidylinostitol-3-kinase (PI3K) is the potential anticancer target in the PI3K/Akt/ mTOR pathway. Here we reviewed the ATP-competitive small molecule PI3K inhibitors in the past few years, including the pan Class I PI3K inhibitors, the isoform-specific PI3K inhibitors and/or the PI3K/mTOR dual inhibitors.

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Understanding how enzyme specificity evolves will provide guiding principles for protein engineering and function prediction. The o-succinylbenzoate synthase (OSBS) family is an excellent model system for elucidating these principles because it has many highly divergent amino acid sequences that are <20% identical, and some members have evolved a second function. The OSBS family belongs to the enolase superfamily, members of which use a set of conserved residues to catalyze a wide variety of reactions.

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Eight new cycloartane-type triterpenoids, cycloartan-24-ene-1alpha,2alpha,3alpha-triol (1), 3beta-acetoxycycloartan-24-ene-1alpha,2alpha-diol (2), 1alpha-acetoxycycloartan-24-ene-2alpha,3beta-diol (3), 3beta-isovaleroyloxycycloartan-24-ene-1alpha,2alpha-diol (4), cycloartan-24-ene-1alpha,3beta-diol (5), cycloartan-23 E-ene-1alpha,2alpha,3beta,25-tetrol (6), and an epimeric mixture of 24 R,25-epoxycycloartane-1alpha,2alpha,3beta-triol (7) and 24 S,25-epoxycycloartane-1alpha,2alpha,3beta-triol (8), together with one known compound, cycloartan-24-ene-1alpha,2alpha,3beta-triol (9), were isolated from the resinous exudates of Commiphora opobalsamum. Their structures were established on the basis of mass spectrometry and multidimensional NMR spectroscopy. The cytotoxicity of compounds 1-9 was evaluated against the PC3 and DU145 human prostate tumor cell lines.

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Naphthalene-2,3-diol-imidazole (1/1).

Acta Crystallogr Sect E Struct Rep Online

August 2008

In the title cocrystal, C(10)H(8)O(2)·C(3)H(4)N(2), inter-molecular O-H⋯O and N-H⋯O hydrogen bonds connect the naphthalene-2,3-diol and imidazole mol-ecules into a two-dimensional supra-molecular framework.

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The crystals of the title salt, C(5)H(12)N(+)·C(11)H(7)O(3) (-), were obtained from a methanol/water solution of 3-hydr-oxy-2-naphthoic acid and piperidine at room temperature. In the crystal structure, the piperidinium cations display a chair conformation and link with hydroxy-naphthoate anions via N-H⋯O and C-H⋯O hydrogen bonds. An intra-molecular O-H⋯O inter-action is also present.

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A lysate-based thermostability and activity profile is described for chloramphenicol acetyltransferase (CAT) expressed in trifluoroleucine, T (CAT T). CAT and 13 single-isoleucine CAT mutants were expressed in medium supplemented with T and assayed for thermostability on cell lysates. Although fluorinated mutants, L82I T and L208I T, showed losses in thermostability, the L158I T fluorinated mutant demonstrated an enhanced thermostability relative to CAT T.

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Article Synopsis
  • Researchers investigated how varying levels of fluorinated amino acids affect the function and stability of an enzyme called chloramphenicol acetyltransferase (CAT).
  • They found that replacing all leucine residues with 5',5',5'-trifluoroleucine (TFL) retains enzymatic activity at room temperature and improves secondary structure, but reduces stability when exposed to heat and solvents.
  • While the enzyme's catalytic activity remains similar to the wild type, increasing TFL levels leads to decreased stability, indicating that enhanced structure from fluorination doesn’t guarantee better overall stability.
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