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Photoactivated riboflavin in the presence of Cu(II) generates reactive oxygen species (ROS) which can hemolyze human red blood cells (RBC). In the present work we examined the effect of sodium azide (NaN3) on RBC in the presence of riboflavin and Cu(II). The addition of NaN3 to the riboflavin-Cu(II) system enhanced K+ loss and hemolysis. The extent of K+ loss and hemolysis were time and concentration dependent. Bathocuproine, a Cu(I)-sequestering agent, inhibited the hemolysis completely. Among various free radical scavengers used to identify the major ROS involved in the reaction, thiourea was found to be the most effective scavenger. Thiourea caused almost 85% inhibition of hemolysis suggesting that *OH is the major ROS involved in the reaction. Using spectral studies and other observations, we propose that when NaN3 is added to the riboflavin-Cu(II) system, it inhibits the photodegradation of riboflavin resulting in increased *OH generation. Also, the possibility of azide radical formation and its involvement in the reaction could not be ruled out.

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In this work, the mild conditions of Mitsunobu reaction were used to convert the hydroxyl group of 6-triphenylmethylaminopenicillanyl alcohol to amines by using different nuleophiles such as phthalimide, di-tert-butyliminodicarboxylate and potassium cyanate. The existence of the β-lactam carbonyl group increased the instability towards nucleophilic attack of refluxing methanol and the four-membered ring was opened. Treating 3-Di-tert-Butoxycarbonylaminomethyl-6-triphenylmethylamino - penicillanate with 50% trifluoroacetic acid in dichloromethane, resulted in the cleavage of triphenylmethyl group and one tert-butyl group. While the removal of both triphenylmethyl groups as well as di-tert-butylamino carbonyl group occurred when 75% trifluoroacetic acid was used. The significance of this study is to synthesize β-lactam derivatives that might to be more resistant to degradation by β-lactamase and hence, therapeutically more effective. في هذا البحث تم استخدام ظروف تفاعل معتدلة باستخدام تفاعلات متسونوبو لتحويل مجموعة الهيدروكسيل من مركب 6-triphenylmethylaminopenicillanyl alcohol لمجموعة الامين باستخدام نيكليوفيلات مختلفة مثل phthalimide،di-tert-butyliminodicarboxylate وpotassium cyanate. بينت هذه الدراسة أن وجود مجموعة الكاربونيل على حلقة البيتا لاكتام ادى الى عدم استقرار الحلقة نحو الهجوم النيوكليوفيلي من الميثانول ونتج عن ذلك فتح الحلقة الرباعية. تفاعل المركب -Di-tert-Butoxycarbonylaminomethyl-6-triphenylmethylamino-penicillanate3 مع حمض trifluoroacetic بتركيز 50% باستخدام محلول ثنائي كلورو ميثان، أدى إلى انشقاق مجموعة من triphenylmethylومجموعة من tert-butyl. في حين تمت إزالة كلاً من مجموعتي triphenylmethylوdi-tert-butylamino carbonyl group عندما تم إستخدام حامض trifluoroacetic بتركيز 75%. خلاصة هذه الدراسة هو امكانية تحضير مشتقات من مركبات تحتوي على حلقة البيتا لاكتام التي يمكن أن تكون أكثر مقاومة للتحلل من قبل البيتا لاكتاميز، وبالتالي من الممكن أن يصبح لها فعالية علاجية أكبر.