Synthetic, mechanistic and kinetic studies on the organo-nanocatalyzed synthesis of oxygen and nitrogen containing spiro compounds under ultrasonic conditions

2016 ◽  
Vol 18 (15) ◽  
pp. 4216-4227 ◽  
Author(s):  
Nongthombam Geetmani Singh ◽  
Makroni Lily ◽  
Shougaijam Premila Devi ◽  
Noimur Rahman ◽  
Aziz Ahmed ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
Spiro Compounds ◽  
Vitamin B ◽  
Spiro Derivatives ◽  
Ultrasonic Conditions

Vitamin B1 functionalised nano-ferrites: an organo-nanocatalyst for the synthesis of various spiro derivatives.

Highly diastereoselective entry to chiral oxindole-based β-amino boronic acids and spiro derivatives

2021 ◽  
Author(s):  
Marco Manenti ◽  
Stefano Gazzotti ◽  
Leonardo Lo Presti ◽  
Giorgio Molteni ◽  
Alessandra Silvani
Keyword(s):  
Boronic Acids ◽  
Spiro Compounds ◽  
Easy Access ◽  
Spiro Derivatives ◽  
Quaternary Stereocenters

We here describe the first Cu-catalysed, diastereoselective 1,2-addition of 1,1-diborylmethane to chiral ketimines for the synthesis of quaternary stereocenters and spiro compounds. The method provides easy access to a range...

Synthesis of Novel Spiro Compounds using Anthrone and Pyrazole-5-thione Moieties: A Michael Addition approach

2007 ◽  
Vol 2007 (8) ◽  
pp. 468-471 ◽  
Author(s):  
Madhukar S. Chande ◽  
Rahul R. Khanwelkar ◽  
Pravin A. Barve
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Spiro Compounds ◽  
Michael Addition Reaction ◽  
Hydrolysis And Condensation ◽  
Spiro Derivatives ◽  
Dieckmann Condensation

Novel routes for the synthesis of spiro derivatives anthrone have been designed using a Michael addition reaction followed by a Dieckmann condensation and Thorpe–Ziegler cyclisation. Bis-Michael addition of pyrazole-5-thione with 1,5-diarylpenta-1,4-dien-3-one gave directly a spiro derivative of pyrazole-5-thione. An enol lactone was synthesised by using mono Michael addition on dimedone, followed by hydrolysis and condensation.

Synthesis of Spiro-Isoxazolidine Derivatives of Methyl α-Isocostate

2019 ◽  
Vol 9 (4) ◽  
pp. 262-267
Author(s):  
Mohamed Zaki ◽  
Abdelouahd Oukhrib ◽  
Mohammed Loubidi ◽  
Ahmed El Hakmaoui ◽  
Marie-Aude Hiebel ◽  
...  
Keyword(s):  
Natural Products ◽  
Therapeutic Agents ◽  
Spiro Compounds ◽  
Dipolar Cycloaddition ◽  
Exocyclic Double Bond ◽  
Plant Resources ◽  
Enantiomerically Pure ◽  
Dittrichia Viscosa ◽  
Spiro Derivatives ◽  
Derivatives Of

Background: In recent decades, natural products are an important source of chemotherapeutics as more than half of the effective cancer drugs can be traced to natural origins. Objective: Moreover, the modification of natural products is one of the most common and fruitful approaches to obtain novel therapeutic agents in medicinal chemistry. Method: Continuing with a research project based on the support of Moroccan plant resources. we report herein the use of α-isocostic acid extracted in enantiomerically pure form from Dittrichia viscosa as a convenient starting material for the synthesis of new eudesmane derivatives. Results: Novel spiro derivatives with a natural scaffold were prepared. Spiro-isoxazolidine derivatives were generated on the exocyclic double bond adjacent to the ester α,β-unsaturated function by 1,3-dipolar cycloaddition of methyl α-isocostate 1 derived from sesquiterpenic isocostic acid, with nitrones 2. Conclusion: This procedure allowed us to generate enantiomerically pure spiro compounds in one diastereoisomer form with a limited number of steps. These compounds were fully characterized by spectroscopic methods.

Discovery of Novel Approach for Regioselective Synthesis of Thioxotriaza-Spiro Derivatives via Oxalic Acid

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 2004-2009 ◽  
Author(s):  
Vindya K. Gopinatha ◽  
Hassan A. Swarup ◽  
Sathees C. Raghavan ◽  
Kempegowda Mantelingu ◽  
Kanchugarakoppal S. Rangappa
Keyword(s):  
Oxalic Acid ◽  
Spiro Compounds ◽  
Regioselective Synthesis ◽  
Amino Group ◽  
Subsequent Reaction ◽  
Unsaturated Ketones ◽  
Novel Approach ◽  
Spiro Derivatives ◽  
One Step ◽  
Acid Catalyzed

A vital approach for the synthesis of a range of novel thioxotriaza-spiro derivatives is described. These new heterocyclic systems are obtained via oxalic acid catalyzed reaction of α,β-unsaturated ketones in the presence of 5,6-diamino-2-mercaptopyrimidine-4-ols; thus, spiro rings are constructed in one step. Notably, this transformation involves condensation of an amino group followed by enamine reaction with alkenes and subsequent reaction promoted by oxalic acid to afford spiro compounds with excellent regioselectivity.

Flavin radicals, conformational sampling and robust design principles in interprotein electron transfer: the trimethylamine dehydrogenase-electron-transferring flavoprotein complex

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Molecular Assembly ◽  
Conformational Sampling ◽  
Trimethylamine Dehydrogenase ◽  
Key Residues ◽  
Electron Transferring Flavoprotein ◽  
Electron Transfer Complex

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.

Schutz vor Insekten

2005 ◽  
Vol 62 (11) ◽  
pp. 713-718 ◽  
Author(s):  
Rudin
Keyword(s):  
Vitamin B ◽  
Eucalyptus Citriodora ◽  
Knock Down

Erfolgreicher Schutz gegen Stiche von blutsaugenden Insekten und Zecken bedingt die konsequente Anwendung geeigneter Maßnahmen. Eine eventuell notwendige Chemoprophylaxe wird dadurch nie ersetzt. Die Umstände, unter denen der Schutz erreicht werden soll, bestimmen die Kombination der zu treffenden Maßnahmen. Von Wohnräumen kann man Insekten mit Mückengittern oder -gaze an Fenstern und Türen oder mittels Klimaanlagen fernhalten. Beim Schlafen kann man sich mit einem Moskitonetz schützen. Diese Maßnahmen können bei Bedarf durch Insektizide ergänzt oder unterstützt werden. Meistens kommen synthetische Pyrethroide entweder als «knock down»-Sprays oder elektroverdampft für die Behandlung von Räumen oder als Imprägnierungsmittel von Netzen und Gittern zum Einsatz. Wenn ein Kontakt nicht durch die Wahl von Aufenthaltsort und -zeit vermeidbar ist, werden außer Haus zum Schutz vor Stichen geeignete Kleidung sowie Repellentien eingesetzt. Kleider sollen möglichst viel Körperfläche bedecken, aus festem Gewebe, nicht eng anliegend und von heller Farbe sein. Eine zusätzliche Behandlung mit Insektiziden ist vorteilhaft. Repellentien werden direkt auf die Haut appliziert. Diethylmethylbenzamin (DEET) zeigt seit vielen Jahren eine verlässliche Wirkung. Ebenfalls verbreitete synthetische Wirkstoffe sind Bayrepel® und IR3535. Sie weisen ein noch etwas geringeres Nebenwirkungsrisiko auf, nachteilig ist jedoch die schwächere Wirkung. Von den pflanzlichen Produkten sind die mit einem Extrakt aus Eucalyptus citriodora die am besten wirksamen. Schwächere Produkte schützen Personen, die für Mücken speziell attraktiv sind, nur ungenügend. Völlig nutzlos sind auf Arm-, Halsbänder oder Kleber aufgetragene Repellentien, sowie Ultraschallgeräte, UV-Lichtfallen oder die Einnahme von Vitamin B1 oder Knoblauch.

Nutritional B12 Deficiency in Infants of Vitamin B12-Deficient Mothers

2011 ◽  
Vol 81 (5) ◽  
pp. 328-334 ◽  
Author(s):  
Oya Halicioglu ◽  
Sezin Asik Akman ◽  
Sumer Sutcuoglu ◽  
Berna Atabay ◽  
Meral Turker ◽  
...  
Keyword(s):  
Megaloblastic Anemia ◽  
Maternal Diet ◽  
Clinical Manifestations ◽  
Serum Vitamin ◽  
Failure To Thrive ◽  
Clinical Findings ◽  
Vitamin B ◽  
Animal Products ◽  
Hematological Evaluation ◽  
Nutritional Vitamin

Aim: Nutritional vitamin B12 deficiency in infants may occur because the maternal diet contains inadequate animal products. Clinical presentations of the infants who had nutritional vitamin B12 deficiency were analyzed in this study. Subjects and Methods: Patients with nutritional vitamin B12 deficiency were enrolled in the study between 2003 and 2010. The diagnosis was based on a nutritional history of mothers and infants, clinical findings, hematological evaluation, and low level of serum vitamin B12. Results: Thirty children aged 1 - 21 months constituted the study group. Poverty was the main cause of inadequate consumption of animal products of the mothers. All infants had predominantly breastfed. The most common symptoms were developmental delay, paleness, apathy, lethargy, anorexia, and failure to thrive. Hematological findings were megaloblastic anemia (83.3 %), thrombocytopenia (30 %), and severe anemia (13.3 %). All of the mothers had low serum B12 levels; eight of them had megaloblastic anemia. Conclusion: The unusual clinical manifestations of vitamin B12 deficiency may also be seen apart from neurological and hematological findings. Nutritional vitamin B12 deficiency due to maternal deficiency might be a serious health problem in infants. Therefore, screening and supplementation of pregnant and lactating women to prevent infantile vitamin B12 deficiency should be considered.

Vitamin B6 Deficiency can Reduce Fuel Storage and Utilization in Physically Trained Rats

2008 ◽  
Vol 78 (2) ◽  
pp. 64-69 ◽  
Author(s):  
Choi ◽  
Cho
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Muscle Protein ◽  
Plasma Free Fatty Acid ◽  
Vitamin B ◽  
Liver Protein ◽  
Protein Levels ◽  
Before And After ◽  
Fuel Storage ◽  
Exercise Muscle

This study investigated the effect of vitamin B6 deficiency on the utilization and recuperation of stored fuel in physically trained rats. 48 rats were given either vitamin B6-deficient (B6–) diet or control (B6+) diet for 4 weeks and were trained on treadmill for 30 minutes daily. All animals were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The DE group was exercised on treadmill for 1 hour just before being sacrificed. Animals in the AE group were allowed to take a rest for 2 hours after being exercised like the DE group. Glucose and free fatty acids were compared in plasma. Glycogen and triglyceride were compared in liver and skeletal muscle. Protein levels were compared in plasma, liver, and skeletal muscle. Compared with the B6+ group, plasma glucose levels of the B6– group were significantly lower before and after exercise. Muscle glycogen levels of the B6– group were significantly lower than those of the B6+ group regardless of exercise. The liver glycogen level of the B6– group was also significantly lower than that of B6+ group during and after exercise. Before exercise, plasma free fatty acid levels were not significantly different between the B6+ and B6– groups, and plasma free fatty acid levels of the B6– group were significantly lower during and after exercise. The muscle triglyceride level of the B6– group was significantly lower than that of the B6+ group before exercise, and there were no differences between B6+ and B6– groups during and after exercise. Liver triglyceride levels were not significantly different between B6+ and B6– groups. Plasma protein levels of the B6– group were lower than those of B6+ before and after exercise. Muscle protein levels of the B6– group were not significantly different from those of the B6+ group. Liver protein levels of the B6– group were significantly lower than that of the B6+ group after exercise. Liver protein levels of both B6+ and B6– groups were not significantly changed, regardless of exercise. Thus, it is suggested that vitamin B6 deficiency may reduce fuel storage and utilization with exercise in physically trained rats.

Homocysteine Levels Show Significant Differences among Mediterranean Dietary Quality Index Variables Compared to Folate and Vitamin B12 Status in Women

2015 ◽  
Vol 85 (3-4) ◽  
pp. 202-210 ◽  
Author(s):  
Ivona Višekruna ◽  
Ivana Rumbak ◽  
Ivana Rumora Samarin ◽  
Irena Keser ◽  
Jasmina Ranilović
Keyword(s):  
Mediterranean Diet ◽  
Diet Quality ◽  
Quality Index ◽  
Fruits And Vegetables ◽  
Reproductive Age ◽  
Dietary Quality ◽  
Vitamin B ◽  
Cross Sectional ◽  
Poor Diet ◽  
The Mediterranean

Abstract. Results of epidemiologic studies and clinical trials have shown that subjects following the Mediterranean diet had lower inflammatory markers such as homocysteine (Hcy). Therefore, the aim of this cross-sectional study was to assess female diet quality with the Mediterranean diet quality index (MDQI) and to determine the correlation between MDQI, homocysteine, folate and vitamin B12 levels in the blood. The study participants were 237 apparently healthy women (96 of reproductive age and 141 postmenopausal) between 25 and 93 years. For each participant, 24-hour dietary recalls for 3 days were collected, MDQI was calculated, and plasma Hcy, serum and erythrocyte folate and vitamin B12 levels were analysed. Total MDQI ranged from 8 to 10 points, which represented a medium-poor diet for the subjects. The strength of correlation using biomarkers, regardless of group type, age, gender and other measured parameters, was ranked from best (0.11) to worst (0.52) for olive oil, fish, fruits and vegetables, grains, and meat, in this order. Hcy levels showed the best response among all markers across all groups and food types. Our study shows significant differences between variables of the MDQI and Hcy levels compared to levels of folate and vitamin B12 in participants with medium-poor diet quality, as evaluated according to MDQI scores.

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