Effect of osmanthus hydrolat on the aroma quality and volatile components of osmanthus black tea.

Osmanthus fragrans is an evergreen shrub with a pleasant fragrance and a wide range of applications in many fields. The condensed hydrolat obtained during the drying process of its fresh flowers was collected in a low-temperature vacuum environment and its sensory evaluation and volatile components were studied. The main aroma compounds in Osmanthus fragrans were dihydro-ß-ionone, nonanal, ß-cyclocitral, ß-ionone, benzaldehyde, α-ionone, and 6-methyl-5-hepten-2-one, whose contents were used as the main evaluation criteria, and the hydrolats obtained under different scenting and drying times were compared. This process can effectively collect the aroma components in Osmanthus fragrans and the optimal drying conditions were 50 °C for 5 h. The hydrolat was used to provide the scent of osmanthus black tea, which had a fresher and mellower taste, while the fragrance of osmanthus was abundant. These results show that osmanthus hydrolat can be used to provide the scent of floral black tea. Chemical compounds studied in this article: (-)-Catechin (PubChem CID: 1203); (-)-epigallocatechin gallate (PubChem CID: 65064); (-)-epicatechin gallate (PubChem CID: 367141); (-)-epigallocatechin (PubChem CID: 72277); (-)-epicatechin (PubChem CID: 72276); (-)-gallocatechin gallate (PubChem CID: 199472); (-)-catechin gallate (PubChem CID: 6419835); (-)-gallocatechin (PubChem CID: 9882981).

Moisture content of tea dhool for the scenting process affects the aroma quality and volatile compounds of osmanthus black tea.

To improve the quality of osmanthus black tea, samples produced with different scenting methods were prepared. The sensory quality was assessed and the characteristic aromatic components were explored using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry. According to the results, osmanthus black tea obtained by adding osmanthus scenting in the fermentation process had the strongest floral aroma. The major contributors to the aroma of osmanthus black tea were identified as ß-ionone, dihydro-ß-ionone, benzeneacetaldehyde, citral, geraniol, and linalool by calculating their relative odor activity values. An analysis of the causes revealed that the moisture content of tea dhool significantly affected the adsorption of fresh flower aroma by tea. The experimental results showed that osmanthus black tea produced using tea dhool containing 30% moisture content had the highest content of crucial aroma components, suggesting the tea dhool under this condition had the strongest adsorption capacity for osmanthus aroma.

Genetic analysis of the PKHD1 gene with long-rang PCR sequencing.

PKHD1 gene mutations are found responsible for autosomal recessive polycystic kidney disease (ARPKD). However, it is inconvenient to detect the mutations by common polymerase chain reaction (PCR) because the open reading frame of PKHD1 is very long. Recently, long-range (LR) PCR is demonstrated to be a more sensitive mutation screening method for PKHD1 by directly sequencing. In this study, the entire PKHD1 coding region was amplified by 29 reactions to avoid the specific PCR amplification of individual exons, which generated the size of 1 to 7 kb products by LR PCR. This method was compared to the screening method with standard direct sequencing of each individual exon of the gene by a reference laboratory in 15 patients with ARPKD. The results showed that a total of 37 genetic changes were detected with LR PCR sequencing, which included 33 variations identified by the reference laboratory with standard direct sequencing. LR PCR sequencing had 100% sensitivity, 96% specificity, and 97.0% accuracy, which were higher than those with standard direct sequencing method. In conclusion, LR PCR sequencing is a reliable method with high sensitivity, specificity and accuracy for detecting genetic variations. It also has more intronic coverage and lower cost, and is an applicable clinical method for complex genetic analyses.

miR-34a inhibits cell proliferation in prostate cancer by downregulation of SIRT1 expression.

MicroRNA-34a (miR-34a) functions as a tumor suppressor gene and inhibits abnormal cell growth by regulating the expression of other genes. The role of miR-34a in regulating sirtuin 1 (SIRT1) in prostate cancer remains unclear. The objective of the present study was to investigate the biological function and molecular mechanisms of miR-34a regulation of SIRT1 in human prostate cancer samples and the human prostate cancer cell line, PC-3. Fresh prostate tissues were obtained from patients, and the miR-34a expression in prostate cancer tissues was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). qPCR and western blotting were performed to assess the effects of miR-34a overexpression on SIRT1 regulation in PC-3 cells, and the cell growth was assessed by Cell Counting Kit-8 (CCK-8). Flow cytometry was used to assess the cell cycle status of the cells. The miR-34a expression levels in prostate cancer tissues were significantly reduced compared with adjacent normal prostate tissues (P<0.05). SIRT1 expression levels in PC-3 cells with over-expression of miR-34a were significantly reduced compared with those in the negative control (P<0.05). The over-expression of miR-34a inhibited PC-3 cells growth and resulted in increased cell cycle arrest compared with the negative control (P<0.05). In conclusion, miR-34a inhibits the human prostate cancer cell proliferation, in part, through the downregulation of SIRT1 expression.