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https://www.readbyqxmd.com/read/29050271/sesquiterpene-binding-gly-leu-ser-lys-co-adaptation-pocket-to-inhibit-lung-cancer-cell-epithelial-mesenchymal-transition
#1
Xiao-Yu Ai, Heng Zhang, Shao-Yan Gao, Yuan Qin, Wei-Long Zhong, Ju Gu, Meng Li, Kai-Liang Qiao, Qin Tian, Zhan-Hong Cui, Jia-Huan Yang, Zhun Bi, Ting Xiao, Shuang Chen, Hui-Juan Liu, Hong-Gang Zhou, Tao Sun, Cheng Yang
Sesquiterpene lactones (SL) have a wide range of applications in anti-tumor and anti-inflammatory therapy. However, the pharmacological mechanism of such substances is not clear. In this study, parthenolide (PTL) was used as an example to explore the anti-tumor effect of natural molecules and their common mechanism. We showed that PTL inhibited the proliferation and migration by reverse EMT via the ERK2/NF-κB/Snail pathway in vivo and in vitro. Interestingly, Multiple potential targets of PTL contain a Gly-Leu-Ser/Lys-"co-adaptation pocket"...
September 19, 2017: Oncotarget
https://www.readbyqxmd.com/read/29049875/a-protocol-for-the-direct-conversion-of-lactones-to-lactams-mediated-by-1-5-7-triazabicyclo-4-4-0-dec-5-ene-synthesis-of-pyridopyrazine-1-6-diones
#2
Danica A Rankic, Cory M Stiff, Christopher W Am Ende, John M Humphrey
We present an operationally simple lactone-to-lactam transformation utilizing diverse amine nucleophiles. The key steps of amidation, alcohol activation and cyclization are all mediated by one reagent (TBD) in a single vessel at room temperature. We illustrate the convenience of this protocol by synthesizing a wide range of N-alkyl, N-aryl and N-hetereoaryl pyridopyrazine-1,6-diones, an important class of medicinally significant lactams. Furthermore, the reported methodology can be applied to the synthesis of milligram to hundred gram quantities of pyridopyrazine-1,6-diones without the use of specialized equipment...
October 19, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29049387/quantifying-the-strength-of-quorum-sensing-crosstalk-within-microbial-communities
#3
Kalinga Pavan T Silva, Prithiviraj Chellamuthu, James Q Boedicker
In multispecies microbial communities, the exchange of signals such as acyl-homoserine lactones (AHL) enables communication within and between species of Gram-negative bacteria. This process, commonly known as quorum sensing, aids in the regulation of genes crucial for the survival of species within heterogeneous populations of microbes. Although signal exchange was studied extensively in well-mixed environments, less is known about the consequences of crosstalk in spatially distributed mixtures of species...
October 19, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/29048906/gold-catalyzed-ring-expansion-of-enyne-lactone-generation-and-transformation-of-2-oxoninonium
#4
Kui Luo, Tongxiang Cao, Huanfeng Jiang, Lianfen Chen, Shifa Zhu
An efficient gold-catalyzed ring-expansion reaction of enyne-lactones to form 2-oxoninonium intermediates is reported. The 2-oxoninonium generated in this work could undergo further 6π electrocyclization and aromatization reaction to produce different aromatic compounds.
October 19, 2017: Organic Letters
https://www.readbyqxmd.com/read/29040936/chemical-profiling-and-quantification-of-dan-deng-tong-nao-capsule-using-ultra-high-performance-liquid-chromatography-coupled-with-high-resolution-hybrid-quadruple-orbitrap-mass-spectrometry
#5
Xiao-Jing Lv, Zhi Sun, Pei-Le Wang, Jing Yang, Tan-Ye Xu, Qing-Quan Jia, Da-Wei Li, Fang-Yi Su, Zhen-Feng Zhu, Jian Kang, Xiao-Jian Zhang
Dan-Deng-Tong-Nao capsule (DDTN) was a traditional Chinese medicine (TCM) formula, and has been widely used for the treatment of stroke clinically which caused by blood stasis. However, the bioactive substances and mechanism are unclear because of the complex compositions in DDTN. In this research, An ultra high-performance liquid chromatography (UHPLC) coupled with hybrid quadruple-orbitrap mass spectrometry (Q-Orbitrap MS) method was utilized to identify the chemical constituents of DDTN. In total, 102 compounds including diterpenes, lactones, flavonoids, and phenolic acids were identified by the accurate masses and fragmentation pathways, and 18 of them were unambiguously determined by comparison of reference standards...
October 7, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/29040306/micheliolide-suppresses-lps-induced-neuroinflammatory-responses
#6
Zhaomeng Sun, Guodong Li, Tanjun Tong, Jun Chen
Microglia-involved neuroinflammation is thought to promote brain damage in various neurodegenerative disorders. Thus, inhibition of microglial over-activation may have a therapeutic benefit for the treatment of neurodegenerative disorders. Micheliolide (MCL) is a sesquiterpene lactone which inhibits various inflammatory response. However, whether MCL can inhibit neuroinflammation caused by LPS-activated BV2 microglia has not yet been explored. In this study, we demonstrated that treatment of BV2 cells with MCL significantly repressed LPS-stimulated nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, as well as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and nitric oxide (NO) induction...
2017: PloS One
https://www.readbyqxmd.com/read/29039760/sea-cucumber-glycosides-chemical-structures-producing-species-and-important-biological-properties
#7
REVIEW
Muhammad Abdul Mojid Mondol, Hee Jae Shin, M Aminur Rahman, Mohamad Tofazzal Islam
Sea cucumbers belonging to echinoderm are traditionally used as tonic food in China and other Asian countries. They produce abundant biologically active triterpene glycosides. More than 300 triterpene glycosides have been isolated and characterized from various species of sea cucumbers, which are classified as holostane and nonholostane depending on the presence or absence of a specific structural unit γ(18,20)-lactone in the aglycone. Triterpene glycosides contain a carbohydrate chain up to six monosaccharide units mainly consisting of d-xylose, 3-O-methy-d-xylose, d-glucose, 3-O-methyl-d-glucose, and d-quinovose...
October 17, 2017: Marine Drugs
https://www.readbyqxmd.com/read/29039675/total-synthesis-of-paralemnolide-a
#8
Hideki Abe, Yuta Ogura, Toyoharu Kobayashi, Hisanaka Ito
The first total synthesis of tricyclic bisnorsesquiterpene paralemnolide A, isolated from the soft coral Paralemnalia thyrsoides, was achieved. This synthesis features the lactonization of the cyclohexene derivative having a tert-butyl ester via stereoselective epoxidation followed by treatment with a Brønsted acid and construction of the novel tricyclic skeleton by an intramolecular Reformatsky-Honda reaction.
October 17, 2017: Organic Letters
https://www.readbyqxmd.com/read/29039204/access-to-alkyl-substituted-lactone-via-photoredox-catalyzed-alkylation-lactonization-of-unsaturated-carboxylic-acids
#9
Wanxing Sha, Shengyang Ni, Jianlin Han, Yi Pan
An efficient photoredox-catalyzed alkylation/lactonization reaction of unsaturated carboxylic acids by using alkyl N-hydroxyphthalimide esters as alkylation reagents has been developed. Varieties of redox-active esters derived from aliphatic carboxylic acids were proved viable in this method, affording alkyl substituted lactones in moderate to good yields. This redox-neutral procedure features mild conditions and operational simplicity, which provides a new strategy for the synthesis of alkyl substituted lactones...
October 17, 2017: Organic Letters
https://www.readbyqxmd.com/read/29038772/revealing-the-genomic-differences-between-two-subgroups-in-lactobacillus-gasseri
#10
Ipputa Tada, Yasuhiro Tanizawa, Akihito Endo, Masanori Tohno, Masanori Arita
Being an autochthonous species in humans, Lactobacillus gasseri is widely used as a probiotic for fermented products. We thoroughly compared the gene contents of 75 L. gasseri genomes and identified two intraspecific groups by the average nucleotide identity (ANI) threshold of 94%. Group I, with 48 strains, possessed 53 group-specific genes including the gassericin T cluster (9 genes) and N-acyl homoserine lactone lactonase. Group II, with 27 strains, including the type strain ATCC 33323, possessed group-specific genes with plasmid- or phage-related annotations...
2017: Bioscience of Microbiota, Food and Health
https://www.readbyqxmd.com/read/29038220/context-memory-formation-requires-activity-dependent-protein-degradation-in-the-hippocampus
#11
Patrick K Cullen, Nicole C Ferrara, Shane E Pullins, Fred J Helmstetter
Numerous studies have indicated that the consolidation of contextual fear memories supported by an aversive outcome like footshock requires de novo protein synthesis as well as protein degradation mediated by the ubiquitin-proteasome system (UPS). Context memory formed in the absence of an aversive stimulus by simple exposure to a novel environment requires de novo protein synthesis in both the dorsal (dHPC) and ventral (vHPC) hippocampus. However, the role of UPS-mediated protein degradation in the consolidation of context memory in the absence of a strong aversive stimulus has not been investigated...
November 2017: Learning & Memory
https://www.readbyqxmd.com/read/29037867/costunolide-specifically-binds-and-inhibits-thioredoxin-reductase-1-to-induce-apoptosis-in-colon-cancer
#12
Weishan Zhuge, Ruijie Chen, Katanaev Vladimir, Xidan Dong, Khan Zia, Xiangwei Sun, Xuanxuan Dai, Miao Bao, Xian Shen, Guang Liang
Colon cancer is one of the leading causes of cancer-related deaths. A natural sesquiterpene lactone, costunolide (CTD), showed inhibition of cancer development. However, the underlying mechanisms are not known. Here, we have examined the therapeutic activity and novel mechanisms of the anti-cancer activities of CTD in colon cancer cells. Using SPR analysis and enzyme activity assay on recombinant TrxR1 protein, our results show that CTD directly binds and inhibits the activity of TrxR1, which caused enhanced generation of ROS and led to ROS-dependent endoplasmic reticulum stress and cell apoptosis in colon cancer cells...
October 13, 2017: Cancer Letters
https://www.readbyqxmd.com/read/29032649/production-of-bacterial-quorum-sensing-antagonists-caffeoyl-and-feruloyl-hsl-by-an-artificial-biosynthetic-pathway
#13
Sun-Young Kang, Bo-Min Kim, Kyung Taek Heo, Jae-Hyuk Jang, Won-Gon Kim, Young-Soo Hong
A new series comprising phenylacetyl‑homoserine lactones (HSL), caffeoyl-HSL and feruloyl-HSL was biologically synthesized using an artificial de novo biosynthetic pathway. We develop an Escherichia coli system containing an artificial biosynthetic pathway that yields phenylacetyl‑HSLs from simple carbon sources. These artificial biosynthetic pathways contained the LuxI-type synthase gene (rpaI) in addition to caffeoyl-CoA and feruloyl-CoA biosynthetic genes, respectively. Finally, the yields for caffeoyl-HSL and feruloyl-HSL were 97...
October 14, 2017: Journal of Microbiology and Biotechnology
https://www.readbyqxmd.com/read/29024315/copper-catalyzed-synthesis-of-gamma-amino-acids-featuring-quaternary-stereocenters
#14
Arjan Willem Kleij, Jose Enrique Gómez, Silvia Gaspa, Wusheng Guo
The first general asymmetric synthesis of gamma,gamma-disubstituted gamma-amino acids via Cu-catalyzed ring opening of non-strained lactones with amines is reported. This approach features ample scope, operational simplicity and wide functional group diversity. The catalytic process allows to access a series of highly functionalized enantioenriched gamma-amino acids featuring quaternary stereocenters with excellent enantiomeric ratios up to 98:2 and excellent yields up to 98%.
October 10, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29022365/detection-of-new-phenylpropanoids-from-dendrobium-chrysanthum
#15
Jinyan Cai, Chao Yang, Tianhong Chen, Lin Zhao
Herba Dendrobii has been documented in the Compendium of Materia Medica, with special efficacy in nourishing Yin and treating diabetes. However, the chemical profile of Dendrobium chrysanthum Lindl. has not been reported yet. The compositions were analysed with UPLC/Q-TOF-MS/MS. 53 compounds were tentatively characterised, and 14 compounds might be new compounds. Some novel lactones of poly-phenylpropanoids were firstly detected, and di-p-hydroxyphenylpropionic acidic p-coumaric acid lactone, a new compound of the first example, was obtained and identified...
October 12, 2017: Natural Product Research
https://www.readbyqxmd.com/read/29019695/total-synthesis-of-biselide-e-a-marine-polyketide
#16
Ichiro Hayakawa, Kazuaki Suzuki, Masami Okamura, Shota Funakubo, Yuto Onozaki, Dai Kawamura, Takayuki Ohyoshi, Hideo Kigoshi
The total synthesis of biselide E, a marine polyketide isolated from the Okinawan ascidian, has been accomplished. The highlight of this approach is the use of the β-elimination reaction of the chloroacetoxy group for the construction of an unstable six-membered α,β,γ,δ-unsaturated lactone portion at the late stage of the total synthesis.
October 11, 2017: Organic Letters
https://www.readbyqxmd.com/read/29019266/liposome-loaded-thermo-sensitive-hydrogel-for-stabilization-of-sn-38-via-intratumoral-injection-optimization-characterization-and-antitumor-activity
#17
Ruixue Bai, Xueqing Deng, Qiong Wu, Xiaomian Cao, Tiantian Ye, Shujun Wang
Main challenges of the clinical use of 7-ethyl-10-hydroxycamptothecin (SN-38) are its facile transition between the active lactone form (SN-38A) and the inactive carboxylate form (SN-38I) under physiological conditions and its low solubility. The purpose of this study was to develop a thermo-sensitive hydrogel system with acidic SN-38 liposomes (SN-38-Lip-Gel) for local chemotherapy to solve these problems and to evaluate its antitumor activity and tissue distribution in tumor-bearing mice. A study of structural conversion between SN-38I and SN-38A under various pH conditions indicated that acidic solution could inhibit the conversion...
October 11, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/29017788/zaluzanin-c-zc-induces-osteoblast-differentiation-through-regulating-of-osteogenic-genes-expressions-in-early-stage-of-differentiation
#18
Kyeong-Min Kim, Won-Gu Jang
Zaluzanin C (ZC) is a sesquiterpene lactones used in herbal medicines. This study examined the effects of ZC on osteoblast differentiation. ZC-induced mRNA expressions levels of osteogenic genes in C3H10T1/2 and MC3T3-E1 cells were determined by RT-PCR and qPCR. ZC regulated the expression of key osteogenic genes in the early stage of differentiation, including distal-less homeobox 5 (Dlx5), DNA-binding protein inhibitor (Id1) and Runt-related transcription factor 2 (Runx2). In addition, ZC increased Runx2 promoter activity, as assessed via a luciferase assay, and Runx2 protein level...
September 30, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/29017132/a-duodecennial-national-synthesis-of-antibiotics-in-china-s-major-rivers-and-seas-2005-2016
#19
REVIEW
Si Li, Wanzi Shi, Wei Liu, Huimin Li, Wei Zhang, Jingrun Hu, Yanchu Ke, Weiling Sun, Jinren Ni
The occurrence of 94 antibiotics in water and sediments from seven major rivers and four seas in China during 2005-2016 was reviewed. Twelve antibiotics were most frequently detected in both water and sediment samples, including 3 sulfonamides (SAs), 2 tetracyclines (TCs), 4 fluoroquinolones (FQs), and 3 macrolides (MLs). Their median concentrations were below 100ng/L and 100ng/g in river water and sediments, respectively. The highest median concentrations were found in water (1.30-176ng/L) and sediments (0...
October 7, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29017095/persistence-and-reduction-of-shiga-toxin-producing-escherichia-coli-serotype-o26-h11-in-different-types-of-raw-fermented-sausages
#20
Christina Böhnlein, Jan Kabisch, Stefanie Müller-Herbst, Gregor Fiedler, Charles M A P Franz, Rohtraud Pichner
Fermented sausages have been identified as source of several outbreaks of Shiga toxin-producing Escherichia coli (STEC). Illnesses linked to non-O157 STEC serotypes appear to be on the rise worldwide, and serogroup O26 is the second most reported in Europe after O157. However, data on the behavior of serogroup O26 in food are rare, so that the aim of this study was to investigate the survival of STEC O26:H11 in different types of fermented sausages ("Teewurst", fast-ripened and long-fermented salami). Challenge studies were performed with an inoculation cocktail which consisted of three STEC O26:H11 strains isolated from human, cattle and food sources...
September 28, 2017: International Journal of Food Microbiology
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