7 research outputs found
A posterior epidural mass causing paraparesis in a 20-year-old healthy individual
We present a case of a posterior epidural abscess at the thoracic vertebral level causing paraparesia in a young, healthy individual with no otherwise predisposing factors, with normal laboratory findings, as diagnosed using fat-suppressed MR imaging. Spinal epidural abscess is a rare condition, encountered mostly in the midthoracic or lower lumbar vertebral levels of elderly patients, that has a high mortality and morbidity (18-31%) when diagnosis and treatment is delayed. It is rarely spontaneous and is usually accompanied by spinal osteomyelitis. Diagnosis is rather easy in cases of vertebral osteomyelitis or when classical clinical, laboratory and imaging findings are present. However, cases of spontaneous development, with no predisposing factors, and lack of abscess suggesting clinical and laboratory findings may be a diagnostic challenge. In such cases, other posterior epidural masses such as schwannoma, neurofibroma, meningioma and hematoma should be considered in the differential diagnosis. Both the clinician and the radiology physician should have a high suspicion of epidural abscesses, because their early diagnosis and treatment is important. In addition to routine MR images, fat-suppressed MR images prove helpful in the diagnosis of spontaneous epidural abscesses by showing the inflammatory changes in the paraspinal area
Trisequential Photooxygenation Reaction: Application to the Synthesis of Carbasugars
4,5-Dimethylenecyclohex-1-ene was subjected to a photooxygenation reaction to introduce oxygen functionalities. The endoperoxide obtained underwent an ene-reaction to form hydroperoxides with 1,3-diene structures. Further addition of singlet oxygen to the diene units resulted in the formation of tricyclic hydroperoxides having three oxygens in the molecule. Cleavage of the oxygen-oxygen bonds followed by epoxidation of the remaining C-C double bond and concomitant ring-opening reaction furnished the isomeric carbasugars
Synthesis and alpha-Glucosidase and alpha-Amylase Inhibitory Activity Evaluation of Azido-and Aminocyclitols
For the synthesis of some azido-and aminocyclitols, (3aRS, 7aSR)-1,3,3a,7a-tetrahydroisobenzofuran was used as the starting material. For further functionalization of the diene unit, the diene was subjected to epoxidation reactions to give mono-and bisepoxides depending on the amount of m-chloroperbenzoic acid used. The ring-opening of the epoxide functionality with NaN3 resulted in the formation of mono- and bisazido cyclitols. The tetrahydrofuran ring was opened in an acid-catalysed reaction with sulfamic acid. The reduction of azide groups to give amines provided various amino-and bisaminocyclitol derivatives. The inhibitory effects of 20 compounds against alpha-glucosidase and alpha-amylase were tested. The results indicated that some of these compounds seem to have good inhibitory activity against alpha-glucosidase, and low inhibitory activity against alpha-amylase. Furthermore, it was demonstrated that the number and position of azides, amines, and hydroxy groups appeared to play an important role in determining the inhibitory potency of these compounds
Synthesis of Bishomoinositols and an Entry for Construction of a Substituted 3-Oxabicyclo[3.3.1]nonane Skeleton
1,3,3a,7a-Tetrahydro-2-benzofuran was used as key compound for the synthesis of various bishomoinositol derivatives. The diene was subjected to an epoxidation reaction for further functionalization of the diene unit. The bisepoxide obtained was submitted to a ring-opening reaction with acid in the presence of water. Various bishomoinositols were synthesized. However, when the reaction was carried out in the presence of acetic anhydride, a substituted 3-oxabicyclo[3.3.1]nonane skeleton was formed. The mechanism of the formation of the products is discusse
Trisequential Photooxygenation Reaction: Application to the Synthesis of Carbasugars
4,5-Dimethylenecyclohex-1-ene was subjected to a photooxygenation reaction to introduce oxygen functionalities. The endoperoxide obtained underwent an ene-reaction to form hydroperoxides with 1,3-diene structures. Further addition of singlet oxygen to the diene units resulted in the formation of tricyclic hydroperoxides having three oxygens in the molecule. Cleavage of the oxygen–oxygen bonds followed by epoxidation of the remaining C–C double bond and concomitant ring-opening reaction furnished the isomeric carbasugars
Trisequential Photooxygenation Reaction: Application to the Synthesis of Carbasugars
4,5-Dimethylenecyclohex-1-ene was subjected to a photooxygenation reaction to introduce oxygen functionalities. The endoperoxide obtained underwent an ene-reaction to form hydroperoxides with 1,3-diene structures. Further addition of singlet oxygen to the diene units resulted in the formation of tricyclic hydroperoxides having three oxygens in the molecule. Cleavage of the oxygen–oxygen bonds followed by epoxidation of the remaining C–C double bond and concomitant ring-opening reaction furnished the isomeric carbasugars