A Research Overview on Arachidonic Acid:Fermentation Regulation and Purification

Arachidonic acid （ARA or AA）, one of the most important polyunsaturated fatty acids （PUFAs）, has various physiological activities and positive effects on human health. ARA production by Mortierella alpina has become a hot topic in recent years, owing to that it is effective, safe and easy to control. How to improve ARA yield and purification efficiency is important to ARA production in M. alpina. Therefore, in this review, we summarized some methods to improve ARA yield： optimization of culture conditions, mycelium aging technologies and metabolic regulation, and the commonly used methods for ARA isolation and purification, to provide a theoretical basis for ARA production by M. alpina fermentation.

A Novel Approach for Production of Colchicine as a Plant Secondary Metabolite by in Vitro Plant Cell and Tissue Cultures

The secondary metabolites synthesized by plants are economically important chemical compounds in the agricultural and industrial areas such as food, perfumery and pharmaceutical sectors. In recent years, attempts for their production by in vitro plant cell and tissue cultures have been accelerated considerably. Colchicine, the principle secondary metabolite of Colchicum autumnale L. and Gloriosa superba L., is an important alkaloid that has poison effect used for treatment of various diseases and plant breeding studies. Presently, colchicine has been produced by using the seeds of C. autumnale L. and the tubers of G. superba L. through different chemical extraction methods. Applying in vitro plant cell and tissue cultures together with metabolic and genetic engineering techniques, large-scale production of colchicine can be achieved from the above two plant species.

Impact of anthocyanin from Malva sylvestris on plasma lipids and free radical

The effects of anthocyanin from Mah,a sylvestris on plasma lipids and free radical were investigated by Reagent Kit method and in vitro assay. High tat model was set up with albino rats that were fed with different dosages of anthocyanin from Malva sylvestris 10.03 g·d^-1, 0.04 g·d ^-1 and 0.05 g·d^-1）. The results showed that the total cholesterol was decreased by 19.7% at an anthocyanin of 0.04 g. d and triglyceride was decreased by 34.4% at an anthocyanin of 0.05 g·d^-1. In vitro assay, some indexes of anthocyanin were measured including the capability of scavenging free radical, reducing force and the capability of anti-lipid peroxidation by orthophenanthroline Fe^＋2 oxidation-reduction method. The results indicated that the clearance rate of free radical reached to 43.46% when the content of anthocyanin was 0.20 mg·mL^-1 and the inhibition ratio of lipid peroxidation reached 18.82% when the content was 0.5 mg·mL^-1. Therefore anthocyanin is a kind of natural and effective free radical remover and antioxidant and can prevent from the formation of the thrombus and reduced the emergence of the cardiovascular disease.

The Roles of Plant Secondary Metabolites from Cowpea Floral Structures in Resistance to the Flower Bud Thrips

Floral structures of six cowpea （Vigna unguiculata） cultivars were analysed for secondary plant metabolites （polyphenols, terpenoids and flavonoids） to study their relationships with resistance to Megalurothrips sjostedti （Trybom）. Polyphenols varied significantly （P 〈 0.001） among the floral structures of the cultivars at the same growth stage. Significant negative correlations were obtained between polyphenols and damage indices （r = -0.57）, mean adult counts （r = -0.56） and mean larval counts （r = -0.64） of resistant cowpea cultivars especially in the late season, indicating that polyphenols play a significant role in cowpea resistance to M. sjostedti. High levels of polyphenols obtained from Sanzibanili and Sewe cultivars, coupled with highly significant correlations between the polyphenols and thrips population on resistant cultivars, and their damage indices, suggests that these polyphenols could be inhibitors or deterrents in this case. Terpenoid extracts （10 mg/mL） of IT90K-277-2, Sewe, Sanzibanili, TVu 1509 and KV - 404-8-1 racemes; KV ~ 404-8-I and TVu 1509 floral buds; IT90K-277-2, Sewe and Sanzibanili flowers caused significant （P 〈 0.001） larval mortalities, since mortality ranged between 56.7%-96.7%. Hence terpenoid extracts from floral structures of the cultivars are biologically active and confers antibiotic resistance to M. sjostedti larvae; this compound could be promising candidates for genetic transformation of cowpea cultivars.

花谢的声音

花开是一种宣告，花谢同样是一种语言，倾听花谢的声音，了解花的语言，体味人性的本质。

花谢，花开

填完志愿书后，忽然发现你不见了，我气呼呼地回家。没想到却被你堵在了半路上，呵，你以为你是电视里的侠客么？神出鬼没，出现时头发上还沾了些草叶。你用亮晶晶的眼睛盯着我，神气地说，李麦子，我送花给你。我红着脸左右看看，生怕会有认识的人经过。你又显出不耐烦的神情来，将右手从背后伸出来，递给我一束狗尾巴草，说，等你等了5年，等到花儿都谢了，就拿束狗尾巴草来代替吧。

Extracts of Zanthoxylum bungeanum regulate cholesterol accumulation induced by sterols and LPS in vitro and in vivo

In this investigation,the effects of PE,EtOAc,and BuOH fractions from Zanthoxylum bungeanum on cholesterol accumulation induced by sterols and LPS were determined in vitro and in vivo.HepG2 cells induced by 25-hydroxychoelsterol and cholesterol were employed as cell model.After treatment with PE,EtOAC,or BuOH fractions,cellular total cholesterol and apolipoprotein B secretion were significantly reduced.In addition,compared with control group,expressions of SREBP2,HMGCR,and ACAT decreased,while CYP27A1,ABCA1,and LDLR levels increased.Cholesterol accumulation was also induced in C57BL/6 mice by LPS and the mice were used as the animal model.Determination of serum TNF-α level and hepatic mRNA expression of TNF-α,IL-6,iNOS,COX-2 revealed that EtOAc and BuOH fractions had anti-inflammatory effects.Furthermore,hepatic total cholesterol was reduced,accompanied by the elevation of LXR-α and ABCA1 gene expression in BuOH fraction treated mice.Since EtOAc and BuOH fractions were found active,bioassay-guided isolation was performed and β-sitosterol,eudesmin,sesamin and syringaresinol-β-D-glucoside were isolated from the fractions.

Gossypol: phytoalexin of cotton

Sesquiterpenoids are a class of 15-carbon secondary metabolites that play diverse roles in plant adaptation to environment. Cotton plants accumulate a large amount of sesquiterpene aldehydes （including gossypol） as phytoalexins against pathogens and herbivores. They are stored in pigment glands of aerial organs and in epidermal layers of roots. Several enzymes of goss- ypol biosynthesis pathway have been characterized, including 3-hydroxy-3-methylglutaryl coenzyme A reductase （HMGR） and farnesyl diphosphate synthase （FPS） that catalyze the formation of the precursor farnesyl diphosphate （FPP）, （＋）-6-cadinene synthase （CDN） which is the first enzyme committed to gossypol biosynthesis, and the downstream enzymes of CYP706B 1 and methyltransferase. Expressions of these genes are tightly regulated during cotton plants development and in- duced by jasmonate and fungi elicitors. The transcription factor GaWRKY1 has been shown to be involved in gossypol path- way regulation. Recent development of new genomic platforms and methods and releases of diploid and tetraploid cotton ge- nome sequences will greatly facilitate the elucidation of gossypol biosynthetic pathway and its regulation.

Protein differential expression in the elongating cotton (Gossypium hirsutum L.) fiber under nitrogen stress

Nitrogen (N) is an essential macronutrient and an important factor limiting agricultural productivity. N deficient or excess conditions often occur during the cotton growth season and incorrect N application may affect cotton fiber yield and quality. Here, the influence of N stress on the cotton fiber proteome was investigated by two-dimensional gel electrophoresis and mass spectrometry. The results indicated that N application rate affects nitrogen accumulation in fiber cells and fiber length. The proteins differentially expressed during N stress were mainly related to plant carbohydrate metabolism, cell wall component synthesis and transportation, protein/amino acid metabolism, antioxidation and hormone metabolism. The most abundant proteins were C metabolism-related. Ten days post anthesis is a critical time for fiber cells to perceive environmental stress and most proteins were suppressed in both N deficient and N excess conditions at this sampling stage. However, several N metabolism proteins were increased to enhance N stress tolerance. Excess N may suppress carbohydrate/energy metabolism in early fiber development much like N deficiency. These results have identified some interesting proteins that can be further analyzed to elucidate the molecular mechanisms of N tolerance.