Pigments of Fungi. LXIX. Total Synthesis of (R)-Ochratoxin α and the Formal Total Synthesis of Ochratoxin

2002 ◽  
Vol 55 (3) ◽  
pp. 213 ◽  
Author(s):  
C. Donner ◽  
M. Gill
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Ochratoxin A ◽  
Propylene Oxide ◽  
Biologically Active ◽  
Acid Component ◽  
Ochratoxin Α ◽  
First Time

(R)-Ochratoxin α, the monochiral carboxylic acid component of the biologically active dipeptide ochratoxin A, is synthesized for the first time over nine steps from (R)-propylene oxide. The method constitutes a versatile and general route to functionalized dihydroisocoumarins.

scholarly journals Analysis of the Carry-Over of Ochratoxin A from Feed to Milk, Blood, Urine, and Different Tissues of Dairy Cows Based on the Establishment of a Reliable LC-MS/MS Method

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2823 ◽  
Author(s):  
Zhiqi Zhang ◽  
Zhichen Fan ◽  
Dongxia Nie ◽  
Zhihui Zhao ◽  
Zheng Han
Keyword(s):  
Dairy Cows ◽  
Ochratoxin A ◽  
Limit Of Quantification ◽  
Fresh Milk ◽  
Liquid Chromatography Tandem Mass ◽  
Ochratoxin Α ◽  
Carry Over ◽  
First Time ◽  
Different Tissues

A rapid and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of ochratoxin A (OTA) and its metabolite ochratoxin α (OTα), for the first time, in dairy cow plasma, milk, urine, heart, liver, spleen, lung, and kidney. The established method was extensively validated by determining the linearity (R2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1–0.2 ng mL−1), recovery (75.3–114.1%), precision (RSD ≤ 13.6%), and stability (≥83.0%). Based on the methodological advances, the carry-over of OTA was subsequently studied after oral administration of 30 μg/kg body weight OTA to dairy cows. As revealed, OTA and OTα were detected in urine, with maximal concentrations of 1.8 ng mL−1 and 324.6 ng mL−1, respectively, but not in milk, plasma, or different tissues, verifying the protection effects of rumen flora against OTA exposure for dairy cows. Moreover, 100 fresh milk samples randomly collected from different supermarkets in Shanghai were also analyzed, and no positive samples were found, further proving the correctness of the in vivo biotransformation results. Thus, from the currently available data, regarding OTA contamination issues on dairy cows, no significant health risks were related to OTA exposure due to the consumption of these products.

Facile Total Synthesis of Thailandepsins D–F: Novel Bicyclic Depsipeptide Histone Deacetylase Inhibitors Isolated from a Microorganism

Synthesis ◽  
2019 ◽  
Vol 51 (06) ◽  
pp. 1419-1426 ◽  
Author(s):  
Tadashi Katoh ◽  
Noel Sayar ◽  
Koichi Narita
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Naturally Occurring ◽  
First Time

The naturally occurring bicyclic depsipeptide histone deacetylase inhibitors thailandepsins D–F were efficiently synthesized for the first time in 49–61% overall yield over five steps, starting from known amine and carboxylic acid segments. The synthesis includes the condensation of the two known starting materials to directly assemble the corresponding seco-acids, which are the key precursors for macrolactonization. The seco-acids are then macrolactonized using the Shiina method to construct the requisite 15-member macrocycles.

Application of Saccharin as an Acidic Partner in the Ugi Reaction for the One-Pot Synthesis of 3-Iminosaccharins

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1214-1218 ◽  
Author(s):  
Sorour Ramezanpour ◽  
Zahra Bigdeli ◽  
Nahid Alavijeh ◽  
Frank Rominger
Keyword(s):  
Carboxylic Acid ◽  
Ugi Reaction ◽  
One Pot ◽  
Acid Component ◽  
Multicomponent Condensation ◽  
One Pot Synthesis ◽  
The One ◽  
First Time

The use of saccharin as a replacement for the carboxylic acid component in an Ugi multicomponent condensation leading to [(1,1-dioxido-1,2-benzisothiazol-3-yl)amino]acetamide (3-iminosaccharin) derivatives is described for the first time.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

Total syntheses and antiproliferative activities of prenostodione and its analogues

2021 ◽  
Author(s):  
Aldahir Ramos Orea ◽  
María Teresa Ramírez-Apan ◽  
Rosa M. Chávez-Santos ◽  
Rodrigo Aguayo-Ortiz ◽  
Clara I Espitia ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Indole Alkaloid ◽  
Total Syntheses ◽  
Antiproliferative Activities

A high-yielding total synthesis of the indole alkaloid prenostodione was completed in 4 steps and 44% overall yield from 1H-indole-3-carboxylic acid. The expedient syntheses of prenostodiones containing distinct substituents at...

scholarly journals Isolation, Structure Elucidation, and Biological Activity of a New Alkaloid from Zanthoxylum rhetsa

2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601
Author(s):  
Karsten Krohn ◽  
Stephan Cludius-Brandt ◽  
Barbara Schulz ◽  
Mambatta Sreelekha ◽  
Pottachola Mohamed Shafi
Keyword(s):  
Biological Activity ◽  
Carboxylic Acid ◽  
Medicinal Plant ◽  
Plant Extract ◽  
Structure Elucidation ◽  
Biologically Active ◽  
Reduction Product ◽  
Pharmacological Properties ◽  
Evergreen Tree

Several biologically active alkaloids (1-4, 6), including a new quinazoline-6-carboxylic acid (1), were isolated from the medicinal plant Zanthoxylum rhetsa, an evergreen tree, native to subtropical areas. Whereas the pharmacological properties of the plant extract and single constituents have been widely tested, we now show that all of the metabolites have antialgal activities, all but 6 are antibacterial, and 6 and the reduction product 5 (derived from 4) are also antifungal.

ChemInform Abstract: Total Synthesis of the Marine Toxin Polycavernoside A (I) via Selective Macrolactonization of a Trihydroxy Carboxylic Acid.

ChemInform ◽  
2010 ◽  
Vol 32 (52) ◽  
pp. no-no
Author(s):  
James D. White ◽  
Paul R. Blakemore ◽  
Cindy C. Browder ◽  
Jian Hong ◽  
Christopher M. Lincoln ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Marine Toxin ◽  
Polycavernoside A

Surface Immobilization of Synthetic Proteins Via Plasma Polymer Interlayers

1998 ◽  
Vol 544 ◽  
Author(s):  
Hans J Griesser ◽  
Keith M McLean ◽  
Gerrit J Beumer ◽  
Xiaoyi Gong ◽  
Peter Kingshot ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Cell Attachment ◽  
Plasma Layer ◽  
Polymeric Materials ◽  
Covalent Immobilization ◽  
Biologically Active ◽  
Plasma Polymer ◽  
Rf Plasma ◽  
Bulk Materials ◽  
Synthetic Proteins

AbstractCoatings of biologically active molecules on synthetic ”bulk“materials are of much interest for biomedical applications since they can in principle elicit specific, predictable. controlled responses of the host environment to an implanted device. However, issues such as shelf life. storage conditions, biological safety, and enzymatic attack in the biological environment must be considered; synthetic proteins may offer advantages. In this study we investigated the covalent immobilization onto polymeric materials of synthetic proteins which possess some properties that mimic those of the natural protein collagen, particularly the ability to form triple helical structures, and thus may provide similar bio-responses while avoiding enzymatic degradation. In order to perform immobilization of these collagen-like molecules (CLMs) under mild reaction conditions, the bulk materials are first equipped with suitable surface groups using rf plasma methods. Plasma polymer interlayers offer advantages as versatile reactive platforms for the immobilization of proteins and other biologically active molecules. Application of a thin plasma polymer coating from an aldehyde monomer is particularly suitable as it enables direct immobilization of CLMs by reaction with their terminal amine groups, using reductive amination chemistry. An alternative route is via plasma polymer layers that contain carboxylic acid groups and using carbodiimnide chemistry. A third route makes use of alkylamme plasma polymer interlayers, which are less process sensitive than aldehyde and acid plasma coatings. A layer of poly-carboxylic acid compounds such as carboxylic acid terminated PAMAM-starburst dendrimers or carboxymethylated dextran is then attached by carbodiimide chemistry onto the amine plasma layer. Amine-terminated CLMs can then be immobilized onto the poly-carboxylic acid layer. Surface analytical methods have been used to characterize the immobilization steps and to assess the surface coverage. Initial cell attachment and growth assays indicate that the biological performance of the CLMs depends on their amino acid sequence.

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