Accumulating evidence suggested that soluble oligomeric β-amyloid protein (Aβ) exerts diverse roles in neuronal cell death, neuroinflammation, oxidative stress, and the eventual dementia associated with Alzheimer’s disease (AD). Developing an agent with multiple properties may be a reasonable strategy for the treatment of AD. In this study, we isolated a novel multifunctional compound named camellikaempferoside B (YCF-2) from Fuzhuan brick tea. YCF-2 consists of kaempferol backbone, p-coumaric acid (p-CA) group, and a novel structure of rhamnopyranosyl group at the C-4′ position, possessing the properties of both kaempferol and p-CA. YCF-2 significantly inhibited Aβ production by decreasing β-secretase activity. Moreover, YCF-2 suppressed Aβ42 fibrillation and facilitated nontoxic oligomer formation by binding to Aβ42 oligomers and by blocking the conformational transition to β-sheet. Furthermore, YCF-2 ameliorated Aβ-induced neuronal cell death, ROS production, inflammatory factor release, and microglia activation by blocking the NF-κB signaling pathway in microglia. These findings indicated that YCF-2 with a novel lead structure has potential applications for drug development for AD treatment.Keywords: aggregation; Amyloid-beta; camellikaempferoside B; microglia; neurotoxicity; β-secretase

•The brewing of tea beer was reported for the first time.•A simple but effective comparison model was designed for volatiles analysis.•The analysis of volatiles was performed by methods of triangular test and SPME–GC–MS.•An interesting interaction was indicated between tea components and lager yeast.Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC–MS analysis. The PCA of GC–MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC–MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested.

•O-Acetyl-7-methoxycamptothecin was reported as a new compound.•A new natural compound, 10-hydroxy-9-methoxycamptothecin, was reported.•The chemotaxonomic significance of Nothapodytes foetida and N. pittosporoides was discussed.•Mappicine and its derivatives as well as isocoumarins are key chemotaxonomic markers of the species.A new alkaloid, O-acetyl-7-methoxycamptothecin (1), was isolated from the roots of Nothapodytes pittosporoides (Icacinaceae), together with seventeen known compounds (2–18). The structures of these compounds were identified by extensive spectroscopic interpretation. Isocoumarins were reported from the investigated genus for the first time. The alkaloids and isocoumarins in N. pittosporoides could serve as its chemotaxonomic markers.

Fuzhuan brick-tea is a special dark tea prepared from the leaves of Camellia sinensis var. sinensis. Its production involves a fungal fermentation stage, which forms the unique flavors and functions by a series of biochemical reactions. Our phytochemical research of the material led to the isolation of two new B-ring fission lactones of flavan-3-ols, fuzhuanins A (1) and B (2). In addition, three other flavan-3-ol derivatives (3–5), three flavone C-glycosides (6–8), eight flavonoid O-glycosides (10–17), five simple phenolics (19–23), two norisoprenoid glycosides (24, 25), two sesquiterpenoids (26, 27), and theobromine (28), as well as two flavonoid anions (9 and 18), were also identified. The structures of these compounds were determined by spectroscopic methods. Compounds 4, 19, 20, 22–24, 26, and 27 were reported for the first time in Camellia spp. and tea. Furthermore, HPLC analysis method was performed to compare the chemical constituents of the before/after fungal fermentation Fuzhuan brick-teas. Compound 1 was indicated as one of the major characteristic constituents generated in the fungal fermentation process. The IC50 value of the antiproliferative activity of 2 on HeLa cells was assayed as 4.48 μM. None of the isolated compounds showed any inhibition activity against the enteric pathogenic microbes at 800 μg/mL by the hole plate diffusion method.