Разработка способа получения производного октреотида для диагностики нейроэндокринных опухолей

Currently the development of technologies for labeling somatostatin with technetium-99m for diagnosing radionuclide neuroendocrine tumors is under way. Somatostatin analogues are binded with technetium99m only by the preliminary addition of a chelating agent. Therefore, it is important to develop a method for preparation of an octreotide derivative by modifying octreotide with precursors: ligands with high chelating ability for its tight binding with technetium-99m. ω-Bis(pyridin-2-ylmethyl)amino)aliphatic acids can be used successfully as such precursors.The purpose of the study was to develop a method for obtaining a new octreotide derivative for diagnosing neuroendocrine tumors.Materials and methods. The somatostatin octreotide analogue was used as the object of the study; succinimid-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used as a chelating agent. Methods of high performance liquid chromatography and mass spectrometry were used to separate and analyze the synthesized compounds.Results. A method to produce an original octreotide derivative using a succinimid-1-yl 6-(bis(pyridin2-ylmethyl)amino)hexanoate as a chelating agent was proposed. The conditions of analytical and semipreparative HPLC for the analysis and purification of the active octreotide derivative (a monosubstituted derivative of the amino acid residue of D-phenylalanine) were suggested.Conclusion. The synthesized derivative of octreotide has a chelating center for strong binding to technetium-99m in its structure, which can be useful for diagnosing neuroendocrine tumors. Введение. В настоящее время разработка технологии мечения аналогов соматостатина технецием99м (99mTc) для радинуклидной диагностики нейроэндокринных опухолей активно проводится по всему миру. Аналоги соматостатина, к которым относится октреотид, связываются с 99mTc только путем предварительного присоединения к ним хелатирующего агента. Поэтому актуальным является модификация октреотида прекурсорами с высокой хелатирующей способностью для прочного связывания 99mTc. В качестве таких прекурсоров успешно могут применяться ω-бис(пиридин-2- илметил)амино)алифатические кислоты.Цель исследования. Разработка способа получения нового производного октреотида, пригодного для диагностики нейроýндокринных опухолей.Материалы и методы. В качестве объекта исследования использовали октреотид – аналог соматостатина. В качестве бифункционального хелатирующего агента использовали сукцинимид-1-ил 6-(бис(пиридин-2-илметил)амино)гексаноат, синтезированный по модифицированной методике с учетом специфики агента. Для разделения и анализа синтезированных соединений применяли методы высокоýффективной жидкостной хроматографии и масс-спектрометрии.Результаты исследования. Предложен способ получения производного октреотида с применением хелатирующего агента сукцинимид-1-ил 6-(бис(пиридин-2-илметил)амино)гексаноата в среде 10 ммоль PBS (рН = 6,0) с добавлением 20%-го ацетонитрила в течение 24 ч. Разработаны условия для анализа и очистки активного производного октреотида с использованием аналитической и полупрепаративной жидкостной хроматографии.Заключение. Впервые в результате модификации октреотида по остатку D-фенилаланина создан центр хелатирования для технеция-99м на основе ω-бис(пиридин-2-илметил)амино)алифатических кислот. Производное октреотида является перспективным для дальнейшего изучения его функциональной пригодности для диагностики нейроэндокринных опухолей.

Ondasetron versus granisetron in the prevention of chemotherapy\u2010induced nausea and vomiting. Results of a prospective randomized trial

Background. A single\u2010institution, prospective, randomized open trial was performed to compare ondansetron and granisetron in the prevention of chemotherapyrelated nausea and vomiting. The effect of antemetic drugs was analyzed indipendently for patients treated with highly emetogenic chemotherapy (Study 1), and those treated with moderately emetogenic regimens (Study 2). Methods. In Study 1. 182 patients treated with chemotherapeutic regimens containing high dose cisplatin (more than 70 mg/m2) were randomized to receive 24 mg of ondasentron intravenously (i. v.) or 3 mg of granisetron i. v. for the control of acute emesis. Patients treated with fractionated chemotherapy and those followed\u2010up for delayed emesis also received 8 mg of ondansetron orally twice a day or 3 mg of granisetron i. v. on the days after Day 1. In Study 2, 164 patients were randomized to receive either 16 mg of ondansetron i. v. or 3 mg of granisetron i. v. to prevent emesis in the first 24 hours. Results. In the ondansetron group in Study 1, a complete response (CR) (i. e., no vomiting, nausea possible) from acute emesis was achieved in 52% of cases, a major response (MR) in 29%, and a minor response (MiR) in 14%. In the granisetron group in Study 1, a CR was seen in 49% of patients, an MR in 24%, and an MiR in 12% Failure was recorded in 5% and 15% of cases in the ondansetron and granisetron groups, respectively. No statistically significant difference in any response category was seen between the two groups. In the ondansetron group, a complete protection from delayed emesis was recorded in 39% of cases, an MR in 32%, an MiR in 21%. and failure in 16%. In the granisetron arm, 36% of the patients had a CR, 22% had an MR, 14% had an MiR, and 14% experienced treatment failure. Again, these differences did not reach statistical significance. In Study 2, no statistical significant difference was observed between the ondansetron arm and the granisetron arm, both for acute and delayed emesis. Both ondansetron and granisetron were tolerated very well by most patients, with no severe side effects. In the group of patients treated with ondansetron, however, the incidence of headache (9%) was higher than in the group treated with granisetron (4%). Conclusions. These data suggest that although both ondansetron and granisetron are very effective drugs for the control of acute emesis, their efficacy against delayed emesis is still not entirely satisfactory. Copyright \ua9 1994 American Cancer Societ

Development of a method for preparing octreotide derivative for diagnosis of neuroendocrine tumors

Currently the development of technologies for labeling somatostatin with technetium-99m for diagnosing radionuclide neuroendocrine tumors is under way. Somatostatin analogues are binded with technetium99m only by the preliminary addition of a chelating agent. Therefore, it is important to develop a method for preparation of an octreotide derivative by modifying octreotide with precursors: ligands with high chelating ability for its tight binding with technetium-99m. ω-Bis(pyridin-2-ylmethyl)amino)aliphatic acids can be used successfully as such precursors.The purpose of the study was to develop a method for obtaining a new octreotide derivative for diagnosing neuroendocrine tumors.Materials and methods. The somatostatin octreotide analogue was used as the object of the study; succinimid-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used as a chelating agent. Methods of high performance liquid chromatography and mass spectrometry were used to separate and analyze the synthesized compounds.Results. A method to produce an original octreotide derivative using a succinimid-1-yl 6-(bis(pyridin2-ylmethyl)amino)hexanoate as a chelating agent was proposed. The conditions of analytical and semipreparative HPLC for the analysis and purification of the active octreotide derivative (a monosubstituted derivative of the amino acid residue of D-phenylalanine) were suggested.Conclusion. The synthesized derivative of octreotide has a chelating center for strong binding to technetium-99m in its structure, which can be useful for diagnosing neuroendocrine tumors