Plum blossom low molecular weight polypeptide protects HaCaT cells against UVB-induced oxidative damage in vitro and underlying mechanism.

BACKGROUND: Increasing amounts of ultraviolet radiation occur as ozone depletion causes the earth's ozone layer to be destroyed, making antioxidant efficacy a research hotspot. Previous studies on plum blossom have mostly focused on Volatile Oils, Flavonoids, Phenylpropanoids, and other compounds, whereas few studies have focused on low molecular weight polypeptide (LMWP) of plum blossom. This research provides a reference for the deep processing and utilization of plum blossom. OBJECTIVES: (a) Plum blossom low molecular weight polypeptides protect HaCaT cells against UVB-induced oxidative damage in vitro and the underlying mechanism. (b) Improve the theoretical basis for the intense processing and utilization of plum blossom. METHODS: The safe concentration of LMWP and the survival rate of HaCaT cells were determined using the CCK-8 experiment. The fluorescence intensity of reactive oxygen species (ROS) was identified using the dichlorofluorescin diacetate (DCFH-DA) method; Superoxide dismutase (SOD) and malondialdehyde (MDA) concentrations were measured in ruptured cells; Western blot analysis was used to examine the expression levels of three proteins: nuclear factor E2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and benzoquinone oxidoreductase 1 (NQO-1). RESULTS: It was noted that a certain concentration of LMWP could promote cell proliferation. In oxidatively damaged HaCaT cells, SOD levels and survival rates were markedly reduced, but ROS and MDA levels were elevated. However, after treatment with LMWP, the survival rate of the cells and SOD levels were markedly increased, and the levels of ROS and MDA were markedly decreased. As shown by Western blotting, the model group exhibited lower levels of Nrf2, HO-1, and NQO-1 expression than the control group, whereas LMWP-treated cells had significantly higher levels of Nrf2, HO-1, and NQO-1 expression than their model-treated counterparts. CONCLUSIONS: LMMP can effectively protect HaCaT cells against oxidative damage in vitro induced by UVB, and the underlying mechanism is linked to the activation of the transcription factor Nrf2.

Enantioselective Synthesis of 3a-Amino-Pyrroloindolines by Copper-Catalyzed Direct Asymmetric Dearomative Amination of Tryptamines.

A direct asymmetric dearomative amination of tryptamines with O-(2,4-dinitrophenyl)hydroxylamine (DPH) was achieved using CuBr-bisoxazoline complex as a catalyst, affording 3a-amino-pyrroloindolines in good to excellent enantioselectivity under mild reaction conditions. Furthermore, the synthetic value of this method was demonstrated in the total synthesis of (-)-psychotriasine in a highly concise manner.

Highly Efficient Formal [2+2+2] Strategy for the Rapid Construction of Polycyclic Spiroindolines: A Concise Synthesis of 11-Demethoxy-16-epi-myrtoidine.

A novel formal [2+2+2] strategy for the stereoselective elaboration of polycyclic indole alkaloids is described. Upon treatment with the catalyst InCl3 (5 mol %), tryptamine-derived enamides reacted readily with methylene malonate, thus enabling rapid and gram-scale access to versatile tetracyclic spiroindolines with excellent diastereoselectivity (21 examples, up to 95 % yield, up to d.r.>95:5). This strategy provides a concise approach to alkaloids isolated from Strychnos myrtoides, as demonstrated by a short synthesis of 11-demethoxy-16-epi-myrtoidine.

Remote ester groups switch selectivity: diastereodivergent synthesis of tetracyclic spiroindolines.

Stereocontrol in the synthesis of structurally complex molecules, especially those with all-carbon quaternary stereocenters, remains a challenge. Here, we reported the preparation of a class of tetracyclic cyclopenta-fused spiroindoline skeletons through Cu(II)-catalyzed intramolecular [3 + 2] annulation reactions of donor-acceptor cyclopropanes with indoles. Both cis- and trans-diastereomers of tetracyclic spiroindolines are accessed with high selectivities by altering the remote ester groups of cyclopropanes. The origins of this stereocontrol are identified using DFT calculations: attractive interactions between the ester group and arene favor the generation of the trans isomer, while the formation of the cis isomer is preferred when steric repulsions become predominant.

The potential of Paeonia lactiflora pall seeds oil as a pure natural cosmetics raw material: In Vitro findings.

BACKGROUND: As a traditional Chinese herbal medicine, Paeonia lactiflora Pall is rich in various active ingredients such as polysaccharides and total flavonoids while having ornamental value. It has potential application value in the development of food and cosmetics. OBJECTIVE: To study the in vitro efficacy of Paeonia lactiflora Pall seeds oil. METHODS: Firstly, the levels of linolenic acid and linoleic acid in Paeonia lactiflora Pall seeds oil were quantified using gas chromatography. The impact of Paeonia lactiflora Pall seeds oil on the proliferation rate of B16F10 cells was assessed through the CCK-8 method, while the melanin content of B16F10 cells was determined using the sodium hydroxide lysis method. The inhibitory effects of Paeonia lactiflora Pall seeds oil on elastase, collagenase and hyaluronidase were evaluated by biochemical techniques in vitro. Lastly, the hen's egg chorioallantoic membrane test (HET-CAM) was conducted to confirm the absence of eye irritation caused by Paeonia lactiflora Pall seeds oil. RESULTS: Paeonia lactiflora Pall seeds oil within a certain volume concentration range (0.5%-4%) had no effect on the proliferation of B16F10 cells. Paeonia lactiflora Pall seeds oil showed significant inhibition of elastase, collagenase and hyaluronidase. Notably, the highest concentration tested, 4% Paeonia lactiflora Pall seed oil, yielded the most pronounced outcomes without causing any irritation. CONCLUSION: A certain concentration of Paeonia lactiflora Pall seeds oil has a significant effect on decreasing the melanin content in B16F10 cells and inhibiting the activities of elastase, collagenase, and hyaluronidase, which can provide a reference for the development of pure natural cosmetics raw materials.

Copper-Catalyzed Enantioselective Cyclopropanation of Internal Olefins with Diazomalonates.

The first enantioselective copper catalyzed cyclopropanation of internal olefins with diazomalonates is reported. This process provides a new method for the synthesis of chiral 1,1-cyclopropane diesters. With a chiral bi-side arm bisoxazoline-copper(I) complex, the reaction performed well over a series of substrates, giving the desired products in good yields (up to 95%) and excellent enantioselectivities (90-95% ee).