[Screening and identification of key enzyme genes for steroidal saponin biosynthesis in Dioscorea zingiberensis under low phosphorus stress]

To investigate the responses of key enzymes involved in steroidal saponin biosynthesis of Dioscorea zingiberensis to low phosphorus stress, we designed three treatments of severe phosphorus stress, moderate phosphorus stress, and normal phosphorus level. The D. zingiberensis plants were collected at the early, middle, and late stages of treatment. The content of total steroidal saponins in different tissues of D. zingiberensis was determined by spectrophotometry for the identification of the critical stage in response to low phosphorus stress. BGI 500 sequencing platform was employed to obtain the transcript information of D. zingiberensis samples at the critical stage of low phosphorus stress, and then a transcriptome library was constructed. The correlation between the expression of genes involved in steroidal saponin biosynthesis and the content of total steroidal saponins was analyzed for the screening of the key enzyme genes in response to low phosphorus stress. Further, the expression patterns of these genes were analyzed by real-time fluorescence PCR(qRT-PCR). The content of total steroidal saponins in D. zingiberensis had obvious tissue specificity under low phosphorus stress, and the early stage of stress was particularly important for D. zingiberensis to respond to low phosphorus stress. A total of 101 593 unigenes were obtained by transcriptome sequencing, of which 77.35% were annotated in NT, NR, SwissProt, KOG, GO, and KEGG. A total of 256 transcripts of known key enzyme genes in the biosynthetic pathway of steroidal saponins were identified. The expression levels of 69 transcripts encoding 18 catalytic enzymes were significantly correlated with the content of total steroidal saponins. The qRT-PCR results showed that several key enzyme genes presented different expression patterns in four tissues under low phosphorus stress. The results indicated that the content of total steroidal saponins and the expression of key enzyme genes regulating steroidal saponin biosynthesis in D. zingensis changed under low phosphorus stress. This study provides the biological information for elucidating the molecular mechanism of steroidal saponin biosynthesis in D. zingensis exposed to low phosphorus stress.

DDQ-Mediated Cross-Dehydrogenative-Coupling Reaction of Secondary Amines with Dialkyl Phosphonates

This work reports a DDQ-mediated cross-dehydrogenative-coupling reaction of secondary amines with dialkyl phosphonates under mild conditions. This reaction proceeds efficiently without involving visible light or transition-metal catalysis. This new approach provides efficient access to biologically important α-aminophosphonates.

[Effect of different initial processing methods on quality of gardenia]

To investigate the effect of different initial processing methods on the quality of Gardenia and determine the best cooking time in gardenia processing through the determination of index components content. The contents of geniposide, crocetin Ⅰ and total iridoid glycosides in Gardenia were determined before storage, six months after storage and one year after storage. During storage, the contents of geniposide, crocetin Ⅰ and total iridoid glycosides in directly dried Gardenia were 1.68%, 0.45% and 6.45% respectively. The contents of geniposide, crocetin Ⅰ and total iridoid glycosides in Gardenia with different steaming time were 1.34%-0.5%, 0.28%-0.06% and 6.09%-1.59% respectively. The contents of geniposide, crocetin Ⅰ and total iridoid glycosides in Gardenia with different boiling time (adding alum)were 1.42%-0.41%, 0.35%-0.07% and 6.40%-1.65% respectively. The direct drying of Gardenia samples could not achieve the function of killing enzyme and protecting glycosides. The enzymes from degradation of the index components were basically destroyed after steaming time of 13 min or boiling (adding alum) time of 8 min, achieving the function of killing enzyme and protecting glycosides.

Poly[[diaqua-bis-(μ(3)-3,5-dicarb-oxy-benzo-ato-κ(3)O(1):O(3):O(5))bis-(μ(3)-5-carb-oxy-ben-zene-1,3-dicarboxyl-ato-κ(3)O(1):O(3):O(5))tetrakis(methylformamide-κO)tri-man-ganese(II)] dimethyl-formamide tetra-solvate]

In the title complex, {[Mn₃(C₉H₄O₆)₂(C₉H₅O₆)₂(C₃H₇NO)₄(H₂O)₂]·4C₃H₇NO}_n, one Mn^II ion sits on an inversion center, and is six-coordinated by four O atoms from four anions (monoanionic and dianionic) derived from benzene-1,3,5-tricarboxylic acid and by two dimethyl­formamide (DMF) mol­ecules in a slightly distorted octa­hedral geometry. The other Mn^II ion is six-coordinated by four O atoms from four monoanionic and dianionic ligands, one DMF mol­ecule and one water mol­ecule in a distorted octa­hedral geometry. The monoanionic and dianionic ligands bridge the Mn^II ions, resulting in the formation of a layered structure parallel to (111) in which all of the carboxyl­ate groups of the anionic ligands coordinate the Mn^II ions in a monodentate manner. Intra- and inter­molecular O—H⋯O hydrogen bonds are present in the structure.

[Comparisons between NIR and HPLC fingerprint on quality stability of Shudihuang decoction pieces]

OBJECTIVE

To establish a new method for evaluating quality stability of Shudihuang decoction pieces with near-infrared spectrum.

METHOD

Clustering analysis was used to distinguish different Shudihuang samples. And comparisons between NIR and HPLC fringerprint.

RESULT

Results of clustering reflected the similar degree among these samples. Compared with HPLC fingerprint, NIR analytical process fast and convenient with exact results.

CONCLUSION

NIR is a feasible and effective approach to examine the quality stability of Shudihuang decoction pieces with unique virtues.