Effect of blackberry anthocyanins and its combination with tea polyphenols on the oxidative stability of lard and olive oil.

To investigate the protective effect of blackberry anthocyanins (BA), tea polyphenols (TP), and their binary mixture on the oxidative stability of edible oils during storage, BA, TP, and their binary mixture were added to lard and olive oil. The changes in peroxide value (PV), thiobarbituric acid reactive substances (TBARS), acid value (AV), and scavenging capacity of DPPH and ABTS•+ of oil samples were evaluated during accelerated storage. BA were found to have a remarkable capability to enhance antioxidant properties, delay lipid oxidation, and inhibit the deterioration both of lard and olive oil at high-temperature processes. Furthermore, the antioxidant synergistic effect of BA and TP was found both in lard and olive oil for the first time. All these results suggested that BA and its combination with TP might possess the potential value to protect the quality of edible oils.

One new 12, 8-guaianolide sesquiterpene lactone with antihyperglycemic activity from the roots of Cichorium intybus.

Three 12, 8-guaianolide sesquiterpene lactones, including a new compound intybusin F (1), and a new natural product cichoriolide I (2), along with six known 12, 6-guaianolide compounds (4-9) were isolated from the roots of Cichorium intybus L. Their structures were determined by extensive spectroscopic analysis. The absolute configurations of new compounds were elucidated based on analysis of the experimental and calculated electronic circular dichroism spectra. Compounds 1, 2, 4, 7, 8 showed significant effects on facilitating the glucose uptake in oleic acid plus high glucose-stimulated HepG2 cells at 50 µM. In addition, compounds 1, 2, 3, 6, 7 exhibited obvious inhibitory effects against NO production, of them, compounds 1, 2, 7 can significantly decrease the secretion of inflammatory cytokines (TNF-α, IL-6 and COX-2) levels in this hyperglycemic HepG2 cell model.

Structural Elucidation and Total Synthesis for the Pair of Unprecedented Polypyridines with Anti-AChE and HIV-1 Protease Activities from Alangium chinense.

Unlike reported pyridine hybrids, 2S (1a) and 2R-alanginenmine A (1b) from Alangium chinense featuring an unprecedented piperidine-bridged polypyridine skeleton represented a pair of alkaloid subtypes with a unique multiple pyridine scaffold. Enlightened by the rare structural characteristics and possible biosynthetic pathway, (±)-alanginenmine A (1) have been achieved in ideal yield by gram-class total synthesis with four steps. In addition, both compounds 1a and 1b exhibited anti-acetylcholinesterase (AChE) and HIV-1 protease activities in the biological activity evaluation. Further, molecular docking was investigated for the mechanism of action between the isolated compounds and HIV-1 protease. The stronger Coulomb interactions and van der Waals interaction, as well as the hydrogen bond interactions of 1a, might be the main cause for its better anti-HIV-1 protease activity than 1b. This work provided a comprehensive research including natural product discovery, bioactivity evaluation, and total synthesis for the new type of leading anti-HIV-1 protease.

Sesquiterpene lactones with anti-inflammatory and cytotoxic activities from the roots of Cichorium intybus.

Cichorium intybus L. (Asteraceae), belonging to the tribe Cichorieae of the family Asteraceae, has a long history as an edible and medicinal food. Sesquiterpene lactones are commonly considered as its major active constituents. In the current study, five unreported sesquiterpene lactones, including one 12,8-guaianolide and four 12,6-guaianolides were isolated from C. intybus roots, as well as 16 known analogues. The planar structures and relative configurations of these compounds were elucidated by extensive spectroscopic analysis. The absolute configurations were determined by the time-dependent density functional theory (TDDFT)-based electronic circular dichroism (ECD) calculation method. Bioassay results showed that seven of the isolates exhibited remarkable NO production inhibitory activity in LPS-stimulated RAW264.7 macrophages, with IC50 values ranging from 1.83 to 38.81 µM. Some of them can significantly decrease the secretion of inflammatory cytokines (TNF-α and IL-6). Cytotoxicity assays demonstrated that intybusins B, as well as four known compounds, displayed obvious inhibitory activities against four human tumor cells, with IC50 values ranging from 9.01 to 27.07 µM.

Chicoric Acid Attenuated Renal Tubular Injury in HFD-Induced Chronic Kidney Disease Mice through the Promotion of Mitophagy via the Nrf2/PINK/Parkin Pathway.

As the main factor in the pathogenesis of chronic kidney disease (CKD), the excessive apoptosis of renal tubular epithelial cells (RTECs) and its underlying mechanism of action are worth further investigation. Chicoric acid (CA), a major active constituent of the Uyghur folk medicine chicory, was recorded to possess a renal protective effect. The precise effect of CA on renal tubular injury in obesity-related CKD remains unknown. In the current study, CA was proven to ameliorate metabolic disorders including overweight, hyperglycemia, hyperlipidemia, and hyperuricemia in high fat diet (HFD)-fed mice. Furthermore, the reverse effect of CA on renal histological changes and functional damage was confirmed. In vitro, the alleviation of lipid accumulation and cell apoptosis was observed in palmitic acid (PA)-exposed HK2 cells. Treatment with CA reduced mitochondrial damage and oxidative stress in the renal tubule of HFD-fed mice and PA-treated HK2 cells. Finally, CA was observed to activate the Nrf2 pathway; increase PINK and Parkin expression; and regulate LC3, SQSTM1, Mfn2, and FIS1 expression; therefore, it would improve mitochondrial dynamics and mitophagy to alleviate mitochondrial damage in RTECs of obesity-related CKD. These results may provide fresh insights into the promotion of mitophagy in the prevention and alleviation of obesity-related CKD.

A new methylene bisflavan-3-ol from the branches and leaves of Potentilla fruticosa.

Dasiphora fruticosa L. (Rosaceae), also known as Potentilla fruticosa L. (syn.), is a hardy deciduous shrub widely distributed in the north temperate regions of the world. Three methylene bisflavan-3-ols (1-3), together with a procyanidin dimer, (-)-afzelechin-(4α→8)-(-)-afzelechin (4) were isolated for the first time from the branches and leaves of the titled plant, in addition to 11 known compounds (5-15). Their structures were elucidated by means of extensive spectroscopic analysis and by comparison with data reported in the literatures. Methylene 6,8-bis(7-O-glucosyl) catechin (1) was determined to be a new dimeric flavan-3-ol glycoside through a methylene linkage between C-8 and C-8 of two units. At a concentration of 128 µg/mL, the known compounds 9 - 13 exhibited antibacterial activities on Escherichia coli, Staphylococcus aureus subsp. aureus, Salmonella enterica subsp. enterica, and Pseudomonas aeruginosa. Compound 12 also showed certain glucose uptake stimulating activity.

Plant Resources, Chemical Constituents, and Bioactivities of Tea Plants from the Genus Camellia Section Thea.

Tea, as one of the most popular beverages with various bioactivities, is commonly produced from the fresh leaves of two widely cultivated tea plants, Camellia sinensis and C. sinensis var. assamica. Both plants belong to the genus Camellia section Thea, which was considered to have 12 species and 6 varieties according to Min's taxonomic system. Most species, except the cultivated species, are known as wild tea plants and have been exploited and utilized to produce tea by the local people of its growing areas. Thus far, six species and varieties have been phytochemically studied, leading to the identification of 398 compounds, including hydrolyzable tannins, flavan-3-ols, flavonoids, terpenoids, alkaloids, and other phenolic and related compounds. Various beneficial health effects were reported for tea and its components, involving antioxidant, antitumor, antimutagenic, antidiabetic, hypolipidemic, anti-inflammatory, antimicrobial, antiviral, antifungal, neuroprotective, hepatoprotective, etc. In this review, the geographical distribution of tea plants and the chemical constituents (1-398) reported from the genus Camellia section Thea and some tea products (green, black, oolong, and pu-erh tea) that have ever been studied between 1970 and 2018 have been summarized, taking species as the main hint, and the main biological activities are also discussed.

C-8 N-Ethyl-2-pyrrolidinone-Substituted Flavan-3-ols from the Leaves of Camellia sinensis var. pubilimba.

Camellia sinensis var. pubilimba, one variety of the genus Camellia sect. Thea (Theaceae), has been used for producing green tea mainly by the local people of its growing areas of Guangxi province, China. Forty compounds, including eight C-8 N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (1-8) and their substituted unit N-ethyl-5-hydroxy-2-pyrrolidinone (9), four flavan-3-ol monomers (10-13) and one dimer (14), nine flavonoids (15-23), three hydrolyzable tannins (24-26), two lignans (27-28), 11 simple phenolics (29-39), and caffeine (40), were first isolated and identified from the leaves. Their structures were determined by detailed spectroscopic analysis and comparison with the literature data and authentic samples. Both 1 and 4 were obtained as a mixture of the N-ethyl-2-pyrrolidinone C-5 enantiomers (1a and 1b and 4a and 4b), respectively, while the resolution of another three pairs of enantiomers (2 and 3, 5 and 6, and 7 and 8) was achieved. Among them, 1b is a new compound whose NMR data together with its enantiomer (1a) were reported for the first time, while 2 and 3 are two new natural products. Most of the isolates exhibited significant antioxidant activities, stronger than ascorbic acid and trolox, while parts of the isolates, particularly C-8 N-ethyl-2-pyrrolidinone-substituted flavan-3-ols, showed obvious inhibitory effects on acetylcholinesterase (AChE). The results indicated that C. sinensis var. pubilimba is a valuable plant resource for tea production.

Antioxidative Flavan-3-ol Dimers from the Leaves of Camellia fangchengensis.

Camellia fangchengensis Liang et Zhong, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic tea species to the south and southwest areas of Guangxi province, People's Republic of China. Known as a wild tea plant, the leaves have been used for producing green tea or black tea by the local people of its growing area. HPLC and LC-MS analysis showed the leaves contain oligomeric catechins as major phenolic components. Further detailed phytochemical study led to the identification of five flavan-3-ol dimers (1-5) including two new ones, fangchengbisflavans A (1) and B (2) from the leaves of C. fangchengensis, together with six known monomers (6-11) and one glucoside (12), in addition to gallic acid (13). Their structures were determined by extensive spectroscopic analysis. Most of the isolates displayed significant antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radical scavenging assays. The results suggested that the leaves of C. fangchengensis, rich in flavan-3-ol oligomers and monomers as potent antioxidants, could be a valuable plant resource for the production of tea and natural beverages.

Asymmetric sorting of ash1p in yeast results from inhibition of translation by localization elements in the mRNA.

ASH1 mRNA localizes at the bud tip of late-anaphase yeast, resulting in accumulation of Ash1p in the daughter nucleus. We show that disruption of the secondary structure, but not the protein coding, of all four ASH1 localization elements resulted in RNA and protein delocalization. Localization of both was incrementally restored by replacement of each of the four elements. However, transposition of the elements to the 3'UTR reinstated the RNA, but not the protein, localization. Interestingly, the mutant ASH1 mRNA was translated more efficiently, suggesting that asymmetry of Ash1p resulted from translational inhibition by the localization elements. In support of this, Ash1p asymmetry could be rescued by slowing its translation.