Research Article
Microorganisms causing the phenomenon of Shenghua were isolated, purified and identified from fermented chili pepper by potato glucose media (PDA) and nutrient agar media (NA) via streak plate method. The purified strains were validated by tie-back test and identified by phenotype and genotype methods. Results showed that two strains were isolated from the fermented chili with Shenghua. It was identified as Pichia kudriavzevii that causing Shenghua by morphological and molecular biology from PDA media while the strain isolated from the NA media that could not cause Shenghua was identified as gram-positive bacterium by microscopic and colony morphology.
The pharmaceutical cocrystals and its engineering is widely accepted phenomenon regarding to the enhancement of aqueous solubility of poorly soluble drugs. The pharmaceutical cocrystals have the great ability to improve the physicochemical properties of drug substance. Cocrystals are formed by the stoichiometric combination of drug substance and the coformer. The drug glimepiride is a third generation oral hypoglycemic sulfonylurea class. Glimepiride is a drug which is get classified as biopharmaceutical classification system (BCS) class II which indicates the glimepiride having low aqueous solubility and high permeability. Cocrystal engineering is a perfect way to increases glimepiride solubility without changing its therapeutic property. The cocrystals were synthesized by the solvent drop grinding as a green chemistry approach. The coformers used to form the cocrystals are succinic acid (SA), Theobromine (TB), caffeine (CF). The synthesized cocrystals are get characterized by vibrational spectroscopy, thermal analysis, molecular crystallography, and optical microscopy. The obtained results shows the formation of cocrystal phase between the drug glimepiride and its coformers.
Spectroscopic and molecular docking studies on the binding mechanism of Mobic and lipase
Under simulated physiological conditions (pH=7.40), the interaction between non-steroidal anti-inflammatory drug mopicol and lipase was studied by fluorescence spectrum, ultraviolet absorption spectrum, circular dichroism spectrum and computer simulation technique. The experimental results showed that Mobic could quench the fluorescence of lipase by static quenching, and the binding site number is about 1. According to Förster's theory of non-radiation energy transfer, the binding distance between Mobic and lipase was obtained, r<7 nm, which indicated that there was non-radiation energy transfer in the system. The thermodynamic parameters were obtained from van't Hoff equation, Gibbs free energy ΔG<0, indicating that the reaction between them was spontaneous, ΔH<0, ΔS>0, indicating that hydrophobic force played a major role in the formation of Mobic and lipase complex. The results of synchronous fluorescence spectra, UV spectra and circular dichroism spectra showed that Mobic changed the conformation of lipase. The molecular docking results showed that the binding position of Mobic was close to the active center, indicating that Mobic could change the microenvironment of amino acid residues at the active center of lipase catalysis. The results of docking showed that there was hydrogen bond between Mobic and lipase, so the interaction between Mobic and lipase was driven by hydrophobic interaction and hydrogen bond.
Microbial synthesis of anti-tumor agent oxysophoridine through one step by filamentous fungus
Sophoridine and oxysophoridine are alkaloids extracted from Chinese traditional medicine with significant antitumor activities. Computer-aided design and preliminary structure-activity relationship studies showed that the biological activity of sophoridine can be improved after oxidation (oxysophoridine) while its toxicity significantly decreased. A new method to prepare oxysophoridine from natural product Sophoridine by biotransformation was established for the first time except for traditional extraction from plants and chemical synthesis. Positive biocatalytic reaction was detected by TLC. Structure of conversion product was elucidated based on NMR spectroscopy. Optimizations of reactions including substrate concentration, pH, conversion time and inoculation quantity were complemented which analyzed by LC-MS. Results showed that filamentous fungus Xylariales. sp F005 (CCTCC M2014660) has the capacity of synthetizing oxysophoridine from sophoridine in the selected 37 strains. The yield of oxysophoridine reached highest at conditions pH 6.0, the third day of conversion time, 5.0 mg substrate and 5% inoculums respectively. The method for preparing oxysophoridine catalyzed by enzymes with green and sustainable synthetic processes was developed.
Review
Developments in encapsulation of insulin: Is oral delivery now possible?
This review presents the possibilities of oral delivery of insulin. Insulin, being readily destroyed/ transformed by the proteolytic enzymes and first-pass effects in the digestive system, has mainly been administered through injection, such as intravenous injection and transdermal injection. With developments in the material sciences, appropriate encapsulation methodologies have been developed that could be employed to protect insulin from the digestive effects of the human GI system, and thereby have opened a gateway of research exploring the oral route of insulin delivery. One approach is to incorporate insulin into an emulsion with an appropriate oil-phase, which protects the insulin from degradation. Coating with natural or synthetic polymeric materials, or with lipids, followed by size-reduction to 100-1000 nm is applied as another common approaches of insulin encapsulation. Other approaches like liposomes, nanogels, etc. are also being explored. This review gives a summary of methods of preparation as well as in vitro and in vivo bioavailability of insulin through these methods. It is observed that the oral bioavailability of insulin intake has increased from about 0.1% to about 20% for encapsulated insulin.