Effect of thermal process on the key aroma components of green tea with chestnut-like aroma.

BACKGROUND: Chestnut-like aroma is one of the unique qualities of Chinese green tea and has become an important factor influencing consumer decisions. However, the chemical formation mechanism of chestnut-like aroma during green tea processing remains unclear. In this study, the dynamic changes of key components contributing to chestnut-like aroma and their precursors were analyzed in fresh leaves, fixation leaves, first baking tea leaves, and green tea. RESULTS: The thermal process had an important effect on volatile components in tea leaves, causing a significant decrease of alcohols and esters and a significant increase of ketones, acids, phenols, and sulfur compounds. Furthermore, 31 volatiles were identified as the key odorants responsible for chestnut-like aroma of green tea, including dimethyl sulfide, methyl isobutenyl ketone, 2-methylbutanal, 2,4-dimethylstyrene, d-limonene, methyl 2-methylvalerate, linalool, decanal, longifolene, phenylethyl alcohol, l-α-terpineol, jasmone, and so on. And the majority of these odorants were only formed in the drying stage. Additionally, isoleucine, theanine, methionine, and glucose were found to be involved in the formation of chestnut-like aroma of green tea. CONCLUSION: The drying process played a vital important role in the formation of chestnut-like aroma of green tea. © 2022 Society of Chemical Industry.

Triterpene saponins from tea seed pomace (Camellia oleifera Abel) and their cytotoxic activity on MCF-7 cells in vitro.

Triterpenoid saponins are the main active ingredients extracted from Camellia oleifera Abel. In this study, crude saponins (Tc) was extracted from tea seed pomace and purified to obtain total saponins (T0). We used a COSMOSIL C18-OPN to separate T0 into three fractions-highly polar saponins (T1), moderately polar saponins (T2), and weakly polar saponins (T3). HPLC-ESI-MS analysis revealed that T2 were mainly composed of components with m/z ([M-H]-) of 1201.5617, 1187.5822, 1245.5862, and 1215.5779. Cell cycle analysis showed that both T0 and T2 inhibited proliferation and induced S phase arrest of MCF-7 cells. Further cell invasion assays demonstrated T0 and T2 also significantly reduced the invasive potential of MCF-7 cells. So T2 extracted from tea seed pomace (Camellia oleifera) may have effective antitumor activity.

Oleiferasaponin A2, a Novel Saponin from Camellia oleifera Abel. Seeds, Inhibits Lipid Accumulation of HepG2 Cells Through Regulating Fatty Acid Metabolism.

A new triterpenoid saponin, named oleiferasaponin A2, was isolated and identified from Camellia oleifera defatted seeds. Oleiferasaponin A2 exhibited anti-hyperlipidemic activity on HepG2 cell lines. Further study of the hypolipidemic mechanism showed that oleiferasaponin A2 inhibited fatty acid synthesis by significantly down-regulating the expression of SREBP-1c, FAS and FAS protein, while dramatically promoting fatty acid ß-oxidation by up-regulating the expression of ACOX-1, CPT-1 and ACOX-1 protein. Our results demonstrate that the oleiferasaponin A2 possesses potential medicinal value for hyperlipidemia treatment.

Cytotoxic and Hypoglycemic Activity of Triterpenoid Saponins from Camellia oleifera Abel. Seed Pomace.

One new and three known triterpenoid saponins were isolated and identified from Camellia oleifera seeds through IR, NMR, HR-ESI-MS and GC-MS spectroscopic methods, namely oleiferasaponin A3, oleiferasaponin A1, camelliasaponin B1, and camelliasaponin B2. The structure of oleiferasaponin A3 was elucidated as 16α-hydroxy-21ß-O-angeloyl-22α-O-cinnamoyl-23α-aldehyde-28-dihydroxymethylene-olean-12-ene-3ß-O-[ß-d-galactopyranosyl-(1→2)]-[ß-d-xylopyranosyl-(1→2)-ß-d-galactopyranosyl-(1→3)]-ß-d-gluco-pyranosiduronic acid. Camelliasaponin B1 and camelliasaponin B2 exhibited potent cytotoxic activity on three human tumour cell lines (human lung tumour cells (A549), human liver tumour cells (HepG2), cervical tumour cells (Hela)). The hypoglycemic activity of oleiferasaponin A1 was testified by protecting pancreatic ß-cell lines from high-glucose damage.

Qualitative and quantitative analysis of triterpene saponins from tea seed pomace (Camellia oleifera Abel) and their activities against bacteria and fungi.

A method using LC-ESI-IT-TOF/MS and LC/UV-ELSD was established to qualitatively analyze triterpene saponins obtained from the tea seed pomace (Camellia oleifera Abel). In addition, the quantitative analysis of oleiferasaponin A1 using LC/UV was developed. The purified total saponins did not exhibit any inhibitory effects at concentrations ranging from 0.1 to 10 mg/mL against the tested bacteria, except for Staphyloccocus aureus and Escherichia coli. By contrast, higher inhibitory activity was seen against the tested fungi, especially against Bipolaris maydis. Following treatment with an MIC value of 250 µg/mL for 24 h, the mycelial morphology was markedly shriveled in appearance or showed flattened and empty hyphae, with fractured cell walls, ruptured plasmalemma and cytoplasmic coagulation or leakage. These structural changes hindered the growth of mycelia.

A new saponin from tea seed pomace (Camellia oleifera Abel) and its protective effect on PC12 cells.

A new triterpenoid saponin, oleiferasaponin A1, was isolated from tea seed pomace (Camellia oleifera Abel). The structure of oleiferasaponin A1 was elucidated on the basis of chemical and physicochemical evidence and was found to be 22-O-cis-2-hexenoyl-A1-barrigenol 3-O-[ß-D-galactopyranosyl(1→2)] [ß-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl(1→3)]-ß-D-glucopyranosiduronic acid. PC12 cells injured with H2O2 were used as the model to test the protective effects of oleiferasaponin A1. The results indicated that oleiferasaponin A1 can potentially prevent the H2O2-induced cell death of PC12 cells.

[Immunophenotyping characteristics of biphenotypic acute leukemia and analysis of curative effect].

This study was aimed to investigate the immunophenotyping characteristics of biphenotypic acute leukemia (BAL) and to analyze its curative efficacy. The four-color direct immunofluorescence staining and CD45/SSC gating analysis of flow cytometry were used to detect the cells of bone marrow and peripheral blood of 45 doubtful cases of BAL, and the immunophenotyping was performed according to the European Group for the Immunological Classification of Leukemia (EGIL) score criterion. The results showed that among 45 doubtful cases of BAL, the co-expression of cCD79a and cMPO was observed in 23 cases of My/B-ALL, with highest level of CD19 expression, followed by CD10; the co-expression of cCD3 and cMPO was observed in 18 cases of My/T-ALL, with highest level of CD7 expression, followed by CD5; the co-expression of cCD3 and cCD79a was found in 4 cases of T/B. Out of 45 cases of BAL, 30 cases showed cTdT expression, 25 cases showed CD34 expression, 31 cases showed CD117 expression. The results also indicated that the expression rate of CD33 was higher than that of CD13 in antigen expression of My/B-ALL and My/T-ALL patients. The complete remission (CR) rate of My/B-ALL with My/T-ALL CD34(+) was lower than that of My/B-ALL with CD34(-), the CR rate of My/B-ALL with CD34(+) was lower than that of My/T-ALL with CD34(-). It is concluded that the co-expression of My/B-ALL antigen has been found to be most common, then followed by My/T-All. cCD3, cCD79a, cMPO have important value for diagnosing and identifying of BAL. The flow cytometry with four-color direct immunofluorescence staining is most specific method for diagnosis of BAL. The clinical prognosis of BAL with low cell differentiation is poor.