Involvement of Transcription Factors and Regulatory Proteins in the Regulation of Carotenoid Accumulation in Plants and Algae.

Carotenoids are essential for photosynthesis and photoprotection in photosynthetic organisms, which are widely used in food coloring, feed additives, nutraceuticals, cosmetics, and pharmaceuticals. Carotenoid biofortification in crop plants or algae has been considered as a sustainable strategy to improve human nutrition and health. However, the regulatory mechanisms of carotenoid accumulation are still not systematic and particularly scarce in algae. This article focuses on the regulatory mechanisms of carotenoid accumulation in plants and algae through regulatory factors (transcription factors and regulatory proteins), demonstrating the complexity of homeostasis regulation of carotenoids, mainly including transcriptional regulation as the primary mechanism, subsequent post-translational regulation, and cross-linking with other metabolic processes. Different organs of plants and different plant/algal species usually have specific regulatory mechanisms for the biosynthesis, storage, and degradation of carotenoids in response to the environmental and developmental signals. In plants and algae, regulators such as MYB, bHLH, MADS, bZIP, AP2/ERF, WRKY, and orange proteins can be involved in the regulation of carotenoid metabolism. And many more regulators, regulatory networks, and mechanisms need to be explored. Our paper will provide a basis for multitarget or multipathway engineering for carotenoid biofortification in plants and algae.

Two new prenylflavonoids from Morus alba.

Two new prenylflavonoids, morusalbols A and B (1 and 2), were isolated from the branches and leaves of Morus alba, together with three known compounds, kuwanon C (3), morusin (4), morusinol (5). The structures of these two prenylflavonoids were elucidated by extensive analyzes of the spectroscopic data.

Comparison of anti-bacterial activity of three types of di-O-caffeoylquinic acids in Lonicera japonica flowers based on microcalorimetry.

The anti-bacterial activities of three types of di-O-caffeoylquinic acids (diCQAs) in Lonicera japonica flowers, a traditional Chinese medicine (TCM), on Bacillus shigae growth were investigated and compared by microcalorimetry. The three types of diCQAs were 3, 4-di-O-caffeoylquinic acid (3, 4-diCQA), 3, 5-di-O-caffeoylquinic acid (3, 5-diCQA), and 4, 5-di-O-caffeoylquinic acid (4, 5-diCQA). Some qualitative and quantitative information of the effects of the three diCQAs on metabolic power-time curves, growth rate constant k, maximum heat-output power Pm, and the generation time tG, total heat output Qt, and growth inhibitory ratio I of B. shigae were calculated. In accordance with a thermo-kinetic model, the corresponding quantitative relationships of k, Pm, Qt, I and c were established. Also, the half-inhibitory concentrations of the drugs (IC50) were obtained by quantitative analysis. Based on the quantity-activity relationships and the IC50 values, the sequence of inhibitory activity was 3, 5-diCQA > 4, 5-diCQA > 3, 4-diCQA. The results illustrate the possibility that the caffeoyl ester group at C-5 is the principal group that has a higher affinity for the bacterial cell, and that the intramolecular distance of the two caffeoyl ester groups also has an important influence on the anti-bacterial activities of the diCQAs.

Process optimization, characterization and evaluation in vivo of oxymatrine-phospholipid complex.

The objective of this study was to prepare oxymatrine-phospholipid complex (OMT-PLC) to enhance oral bioavailability of oxymatrine. A central composite design approach was used for process optimization. The physicochemical properties of the complex obtained by optimal parameters were investigated by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and N-octanol/water partition coefficient. Compared with those of the physical mixture or oxymatrine, the hepatocytes permeability of oxymatrine-phospholipid complexes was studied. The concentrations of oxymatrine after oral administration of OMT-PLC at different time in rats were determined by HPCE. Multiple linear regression analysis for process optimization revealed that the acceptable OMT-PLC was obtained wherein the optimal values of X(1), X(2) and X(3) were 3, 60 degrees C and 3 h, respectively. The oxymatrine and phospholipids in the OMT-PLC were combined by non-covalent bond, not forming a new compound. The better hepatocytes permeability was obtained by the OMT-PLC. Pharmacokinetic parameters of the complex in rats were T(max) 2.17 h, C(max) 0.437 microg ml(-1), AUC(0-infinity) 9.43 microg h ml(-1), respectively. The bioavailability of oxymatrine in rats was increased remarkably after oral administration of OMT-PLC (p<0.05), compared with those of oxymatrine or the physical mixture. This was mainly due to an improvement of the solubility of OMT-PLC.

Simultaneous determination of seven bioactive lignans in Herpetospermum caudigerum by RP-HPLC method.

A reversed-phase high-performance liquid chromatographic method with diode array detection was established to simultaneously determine the seven bioactive lignans in Herpetospermum caudigerum, namely ent-isolariciresinol (1), dehydrodiconiferyl alcohol (2), herpetrione (3), herpetin (4), herpetetrone (5), herpetotriol (6) amd herpetal (7). The HPLC assay was performed on a Restek Pinnacle DB C18 column (250 x 4.6 mm, 5 microm) with gradient elution of acetonitrile and 0.1% phosphoric acid within 65 min. The detection wavelength was 240 nm. The flow-rate was 1.0 mL/min. All calibration curves showed good linearity (r2 > 0.9998) within test ranges. The method was reproducible with intra- and inter-day variation of less than 1.98%. The method provided good accuracy with recoveries in the range 95.19-102.64% with RSDs less than 1.52%. The method was successfully applied to the quantification of seven constituents in 15 H. caudigerum samples collected from different cities. The results indicated that the developed assay could be considered as a suitable quality control method for H. caudigerum.

Development and optimization of intravenous puerarin emulsions formation by a novel complex-phase inversion-homogenization technology.

To decrease the hemolysis side effect of puerarin, a novel approach of Complex-Phase Inversion-Homogenization (CPIH) Technology was established to prepare intravenous puerarin emulsions. Preparation of puerarin submicron emulsion were optimized by central composite design, and the physicochemical properties were evaluated. Puerarin phospholipid complexs prepared by puerarin and phospholipids at a ratio of 1 : 1.2. In order to improve the product quality, a central composite design was applied to optimize the critical process variables, such as emulsification time, stirring velocity and homogenization press, and the results were modeled statistically. Puerarin phospholipid complexs prepared were identified by fourier transform infrared spectrophotometry. The datas showed that the parameters had great effect on the response values. The particle size, span of dispersity and entrapment efficiency of puerarin emulsions prepared using the optimal parameters settings were 218.23 nm, 0.6284 and 87.32%, respectively. These meant that over 87% of the drug was located at the surfactant interface and oil droplet, the concentration of puerarin in aqueous was rarely. And the puerarin emulsion prepared by CPIH technology were sufficient stable for 90 d. The CPIH technology can be used as a general formulation principle for drugs which are slightly soluble in water and poorly soluble in oils.

Hepatitis B virus inhibiting constituents from Herpetospermum caudigerum.

From the ethanol extract of the seeds of Herpetospermum caudigerum wall, one new lignan compound 1, was isolated and characterized along with three known compounds 2, 3 and 4. The structure elucidation of the isolated new compound was performed on the basis of spectroscopic and chemical evidence. The structures of known compounds were determined by comparison of spectral data and physical data with those previously reported. The activity inhibiting hepatitis b virus was evaluated. Preliminary studies showed that compound 1 and 2 displayed promising inhibitory potential against hepatitis b virus.