Impacts of microplastic and seawater acidification on unicellular red algae: Growth response, photosynthesis, antioxidant enzymes, and extracellular polymer substances.

Microplastics (MPs) pollution and seawater acidification have increasingly become huge threats to the ocean ecosystem. Their impacts on microalgae are of great importance, since microalgae are the main primary producers and play a critical role in marine ecosystems. However, the impact of microplastics and acidification on unicellular red algae, which have a unique phycobiliprotein antenna system, remains unclear. Therefore, the impacts of polystyrene-MPs alone and the combined effects of MPs and seawater acidification on the typical unicellular marine red algae Porphyridium purpureum were investigated in the current study. The result showed that, under normal seawater condition, microalgae densities were increased by 17.75-41.67 % compared to the control when microalgae were exposed to small-sized MPs (0.1 µm) at concentrations of 5-100 mg L-1. In addition, the photosystem II and antioxidant enzyme system were not subjected to negative effects. The large-sized MPs (1 µm) boosted microalgae growth at a low concentration of MPs (5 mg L-1). However, it was observed that microalgae growth was significantly inhibited when MPs concentration increased up to 50 and 100 mg L-1, accompanied by the remarkably reduced Fv/Fm value and the elevated levels of SOD, CAT enzymes, phycoerythrin (PE), and extracellular polysaccharide (EPS). Compared to the normal seawater condition, microalgae densities were enhanced by 52.11-332.56 % under seawater acidification, depending on MPs sizes and concentrations, due to the formed CO2-enrichment condition and appropriate pH range. PE content in microalgal cells was significantly enhanced, but SOD and CAT activities as well as EPS content markedly decreased under acidification conditions. Overall, the impacts of seawater acidification were more pronounced than MPs impacts on microalgae growth and physiological responses. These findings will contribute to a substantial understanding of the effects of MPs on marine unicellular red microalgae, especially in future seawater acidification scenarios.

Lewis acid catalyzed Markovnikov hydrobromination and hydrochlorination of alkynes using TMSX (X = Br, Cl).

Markovnikov hydrobromination and hydrochlorination of alkynes were achieved using TMSX (X = Br, Cl) instead of corrosive HX (X = Br, Cl) as the bromination and chlorination reagents. Mn(OAc)2·4H2O was used as the hydrobromination catalyst for electron-neutral/rich alkynes. For the hydrobromination of electron-deficient alkynes and hydrochlorination of alkynes, Zn(OAc)2·2H2O was employed as the catalyst. Mechanistic studies suggested that the in situ formed TMS-substituted alkyne might be a reactive intermediate and the proton of the terminal alkyne should be a hydrogen source for the hydrohalogenation reaction.

Enhanced microalgal biomass and lipid production with simultaneous effective removal of Cd using algae-bacteria-activated carbon consortium added with organic carbon source.

Recently, using microalgae to remediate heavy metal polluted water has been attained a huge attention. However, heavy metals are generally toxic to microalgae and consequently decrease biomass accumulation. To address this issue, the feasibility of adding exogenous glucose, employing algae-bacteria system and algae-bacteria-activated carbon consortium to enhance microalgae growth were evaluated. The result showed that Cd2+ removal efficiency was negatively correlated with microalgal specific growth rate. The exogenous glucose alleviated the heavy metal toxicity to algal cells and thus increased the microalgae growth rate. Among the different treatments, the algae-bacteria-activated carbon combination had the highest biomass concentration (1.15 g L-1) and lipid yield (334.97 mg L-1), which were respectively 3.03 times of biomass (0.38 g L-1) and 4.92 times of lipid yield (68.08 mg L-1) in the single microalgae treatment system. Additionally, this algae-bacteria-activated carbon consortium remained a high Cd2+ removal efficiency (91.61%). In all, the present study developed an approach that had a great potential in simultaneous heavy metal wastewater treatment and microalgal lipid production.

[Research progress on chemical constituents and biological activities from Turpinia species].

Turpinia species have been used as local Chinese medicines. It has been widely concerned about their antibacterial and anti-inflammatory effects. Modern studies showed that the chemical constituents of Turpina species include flavonoids, triterpenoids, megastigans and phenoli acids. Its pharmacological research mainly focused on antibacterial, anti-inflammatory, antioxidant, analgesic, and immuneregulation effect. In this paper, the chemical compositions and pharmacological activities of Turpinia species were summarized, in order to provide scientific basis for the further development and utilization of Turpinia species.

[Sesquiterpenes with anti-metastasis breast cancer activity from Chloranthus henryi].

To study sesquiterpenes with anti-metastasis breast cancer activity from Chloranthus henryi, ten sesquiterpenes ,zedoarofuran (1), chlorajapolide D (2), 4ß, 8ß-dihydroxy-5α(H)-eudesm-7(11)-en-8, 12-olide (3), curcolonol (4), lasianthuslactone A (5), chlomultin C (6), (1E,4Z)-8-hydroxy-6-oxogermacra-1(10), 4, 7(11) -trieno-12, 8-lactone (7), shizukanolide E (8) , shizukanolide F (9) , 9α-hydroxycurcolonol (10), and five bis-sesquiterpenes, shizukaol B (11), shizukaol C (12) , cycloshizukaol A (13) , sarcandrolide B (14) , henriol A(15), were isolated by using different kinds of column chromatography methods from the ethyl acetate part of Ch.henryi and their structures were identified based on spectroscopic methods. Compounds 2, 8, 9, and 10 were obtained from the genus Chloranthus for the first time. Compounds 2, 5, 8-10, 12,and 14 were obtained from this plant for the first time. Some isolated compounds were subjected to evaluate the anti-metastasis breast cancer activity by using pharmacological methods, and only compounds 4, 11, and 12 were potent active.