Evaluation of Astringency and Tannin Content in ‘Xichu’ Persimmons Using Near Infrared Spectroscopy

Carbon dioxide treatment to reduce soluble tannins and astringency in persimmons is sometimes ineffective. Near-infrared spectroscopy was used to develop a predictive model for soluble tannin content and persimmon classification. A model using averaged spectra collected in the interactance mode showed better performance (correlation coefficient of prediction, r_p = 0.95 and root mean square error of prediction, RMSEP = 0.17% w/w) than that from the transmittance mode (r_p = 0.94 and RMSEP = 0.19% w/w). Models generated using spectra from the stem-end or middle plane flesh and whole fruit were comparable. Classification accuracy of 97.1% was achieved using stem-end flesh spectra. Therefore, near-infrared spectroscopy is a rapid and non-destructive technique with potential applications in the estimation of persimmon tannin content.     

The Influence of Drug-Excipient and Drug-Polymer Interactions on Butt Adhesive Strength of Ranitidine Hydrochloride Film-Coated Tablets

ABSTRACT

The influence of fillers and polymeric films on adhesive strength of hydroxypropyl methylcellulose (HPMC) and Eudragit E100® films coated on ranitidine HCl tablets containing either spray-dried rice starch (SDRS) or lactose monohydrate as fillers after storage at 45°C/75% RH for four weeks was investigated by the use of butt adhesion technique. The adhesive strength of film-coated tablets of fillers without drug was found to slightly decrease after storage. In contrast, the adhesive strength of drug-containing film-coated tablets significantly reduced, the degree of which was higher for Eudragit E100® than HPMC. Physicochemical characterization by employing differential scanning calorimetry (DSC) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed that the drug was obviously incompatible with lactose and possibly mild interaction with Eudragit E100® was suggested. The results indicated that the adhesive strength of film-coated tablets would be affected not only by the drug-excipient interaction, but also by the drug-polymeric film interaction.     

The influence of drug-excipient and drug-polymer interactions on butt adhesive strength of ranitidine hydrochloride film-coated tablets

The influence of fillers and polymeric films on adhesive strength of hydroxypropyl methylcellulose (HPMC) and Eudragit E100® films coated on ranitidine HCl tablets containing either spray-dried rice starch (SDRS) or lactose monohydrate as fillers after storage at 45°C/75% RH for four weeks was investigated by the use of butt adhesion technique. The adhesive strength of film-coated tablets of fillers without drug was found to slightly decrease after storage. In contrast, the adhesive strength of drug-containing film-coated tablets significantly reduced, the degree of which was higher for Eudragit E100® than HPMC. Physicochemical characterization by employing differential scanning calorimetry (DSC) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed that the drug was obviously incompatible with lactose and possibly mild interaction with Eudragit E100® was suggested. The results indicated that the adhesive strength of film-coated tablets would be affected not only by the drug-excipient interaction, but also by the drug-polymeric film interaction.     

Physicochemical properties of amphotericin B liposomes prepared by reverse-phase evaporation method

The physicochemical properties of phosphatidylcholine-cholesterol liposomes containing amphotericin B and prepared by reverse-phase evaporation method were studied. Uniformly dispersed liposomal suspensions were obtained by employing 3:1 ratio (by volume) of diethyl ether to normal saline, 5 min sonication time at 7°C, and evaporation of diethyl ether at 25°C. Microscopic examination showed that the prepared liposomes were spheroids with unilamellar, oligolamellar, or multilamellar structure. The liposomes containing amphotericin B 2.0 mol% of total lipid led to the highest percentage of drug entrapment. Liposomes with maximum entrapment efficiency were obtained from using 250 µmol of total lipid. The liposomal amphotericin B possessing the highest drug entrapment efficiency (approximately 95%) with particle size range of 1307-1451 nm was the one composed of 1:1 molar ratio of phosphatidylcholine to cholesterol.     

Evaluation of pomelo maturity based on acoustic response and peel properties

This research investigated the maturity assessment of pomelo using acoustic properties obtained from an impact of fruit, optical properties of the peel and variables related to oil glands from peel images. Pomelo samples were harvested at 5.5, 6.0, 6.5 and 7.0 months after anthesis. All nondestructive variables were used to build qualitative models with partial least squares discriminant analysis. The classification model based on the nondestructive variables showed that fruits could be separated into immature, early‐mature and late‐mature groups with an accuracy of 96.7%. The important variables contributing to the classification were the impact response based on the second‐order resonant frequency and the difference of green colour between the oil gland and the peel.     

Copper‐Free Postsynthetic Labeling of Nucleic Acids by Means of Bioorthogonal Reactions

Postsynthetic modification of nucleic acids has the advantage that the chemical development of only a few building blocks is necessary, each bearing a chosen reactive functional group that is applicable to its reactive counterpart for a variety of different labeling types. The reactive group is either linked to phosphoramidites for chemical synthesis on solid phase or attached to nucleoside triphosphates for application in primer extension experiments and PCR. Chemoselectivity is required for this strategy, together with bioorthogonality to perform these labelings in living cells or even organisms. Currently, the copper‐free reactions include strain‐promoted 1,3‐dipolar cycloadditions, “photoclick” reactions, Diels–Alder reactions with inverse electron demand, and nucleophilic additions. The majority of these modification strategies show good to excellent reaction kinetics, an important prerequisite for labeling inside cells and in vivo in order to keep the concentrations of the reacting partners as low as possible.     

1,2,4‐Triazine‐Modified 2′‐Deoxyuridine Triphosphate for Efficient Bioorthogonal Fluorescent Labeling of DNA

In order to establish the Diels–Alder reaction with inverse electron demand for postsynthetic DNA modification, a 1,2,4‐triazine‐modified 2′‐deoxyuridine triphosphate was synthesized. The bioorthogonally reactive 1,2,4‐triazine group was attached at the 5‐position of 2′‐deoxyuridine by a flexible alkyl linker to facilitate its acceptance by DNA polymerases. The screening of four DNA polymerases showed successful primer extensions, using a mixture of dATP, dGTP, dCTP, and the modified 2′‐deoxyuridine triphosphate, by using KOD XL or Vent polymerase. The triazine moiety was stable under the conditions of primer extension, which was evidenced by labeling with a BCN‐modified rhodamine at room temperature in yields of up to 82 %. Two or three modified bases could be incorporated in quantitative yields when the modification sites were separated by three base pairs. These results establish the 1,2,4‐triazene group as a bioorthogonally reactive moiety in DNA, thereby replacing the problematic 1,2,4,5‐tetrazine for postsynthetic labeling by the Diels–Alder reaction with inverse electron demand.