Some lipodepsipeptides produced by Pseudomonas syringae pv. syringae showed strong antimycobacter... more Some lipodepsipeptides produced by Pseudomonas syringae pv. syringae showed strong antimycobacterial activity towards Mycobacterium smegmatis. MIC values found were between 1.5-3.2 microg/ml, which is comparable to some primary drugs for tuberculosis. Among the lipodepsipeptides, Syringomycin E (SRE) appears to be the most potent antimycobacterial agent.
Bladder carcinoma is among the most frequent cancer types especially among men. Intravesical inst... more Bladder carcinoma is among the most frequent cancer types especially among men. Intravesical instillation of attenuated strain of Mycobacterium bovis, Bacillus Calmette-Guerin is the standard treatment of medium and high risk patients. It is thought that the effect is through stimulation of the immune system. Since, the use of live mycobacteria may yield to deathly side effects, intensive research is in progress to obtain more potent and less harmful treatment alternatives. Applications of mycobacteria together with other immunostimulants, use of genetically modified organisms, or use of nonpathogenic strains such as Mycobacterium phlei are examples to such researches. Cell wall is sufficient for antitumoral activity. Our research group investigated the immunostimulating activity of several cell wall subfractions of Mycobacterium phlei and showed that the heat stable, water soluble structures, instable to protein denaturating agents and do not contain DNA might be responsible for these effects. Next, immunostimulating activity of 88 mycobacteria strains were investigated and found out that 12 nonpathogenic, rapid growing strains might be an alternative to Mycobacterium phlei. Separation of the cell wall components of these strains by multidimensional HPLC and identification of the structures is in progress. The findings so far obtained resemble the findings obtained with Mycobacterium phlei. More detailed peptidomics and proteomics studies to isolate and characterize these structures may shed light on the mechanism of action of these components and lead to preparation of less harmful antitumoral agents. Further study with animal models is also required to show the in vivo effects of these substances.
S ekonder metabolitler, organizma herhangi bir stres durumuyla karşılaştığı zaman faaliyete geçen... more S ekonder metabolitler, organizma herhangi bir stres durumuyla karşılaştığı zaman faaliyete geçen özelleşmiş metabolik yollar tarafından üretilirler. Bu ürünlerin ara metabolizma ürünlerinden farkı, organizmanın büyümesi ve üremesi için mutlak gerekli olmamalarıdır. Buna rağmen organizma için önemli birtakım fonksiyonlar üstlenirler. Atıkların uzaklaştırılması, detoksifikasyon, savunma ve hücreler arası haberleşme bu fonksiyonlar arasındadır . Üretildikleri organizma için üstlendikleri bu çeşitli görevlerin dışında sekonder metabolitler antibiyotik, kemoterapötik, pestisid, immünsüpresif, antilipolitik ajan gibi çok çeşitli farmasötik fonksiyonlara da sahiptir ve bu etkileri nedeniyle yaygın şekilde kullanılmaktadır . Fonksiyonlarındaki çeşitliliğe benzer şekilde, bu bileşikler kimyasal yapıları bakımından da çok büyük çeşitlilik gösterirler. Bu makalede, ribozom dışı yolla sentezlenen oligopeptid yapısındaki sekonder metabolitler (nonribozomal peptidler) ele alınacak ve sentezlenme mekanizması incelenecektir.
To investigate the cytokine-stimulating activity of several Mycobacterium phlei cell wall extract... more To investigate the cytokine-stimulating activity of several Mycobacterium phlei cell wall extracts. Th e bacillus Calmette-Guérin application is the gold standard treatment for some types of superfi cial bladder carcinoma. However, its usage is limited due to its harmful side eff ects. Intensive research has been carried out to fi nd less toxic and more potent therapeutic agents for treatment. Researchers focus on M. phlei for this purpose. Th e cell wall extract of M. phlei is suffi cient for antitumoral activity.
Some lipodepsipeptides produced by Pseudomonas syringae pv. syringae showed strong antimycobacter... more Some lipodepsipeptides produced by Pseudomonas syringae pv. syringae showed strong antimycobacterial activity towards Mycobacterium smegmatis. MIC values found were between 1.5-3.2 microg/ml, which is comparable to some primary drugs for tuberculosis. Among the lipodepsipeptides, Syringomycin E (SRE) appears to be the most potent antimycobacterial agent.
Bladder carcinoma is among the most frequent cancer types especially among men. Intravesical inst... more Bladder carcinoma is among the most frequent cancer types especially among men. Intravesical instillation of attenuated strain of Mycobacterium bovis, Bacillus Calmette-Guerin is the standard treatment of medium and high risk patients. It is thought that the effect is through stimulation of the immune system. Since, the use of live mycobacteria may yield to deathly side effects, intensive research is in progress to obtain more potent and less harmful treatment alternatives. Applications of mycobacteria together with other immunostimulants, use of genetically modified organisms, or use of nonpathogenic strains such as Mycobacterium phlei are examples to such researches. Cell wall is sufficient for antitumoral activity. Our research group investigated the immunostimulating activity of several cell wall subfractions of Mycobacterium phlei and showed that the heat stable, water soluble structures, instable to protein denaturating agents and do not contain DNA might be responsible for these effects. Next, immunostimulating activity of 88 mycobacteria strains were investigated and found out that 12 nonpathogenic, rapid growing strains might be an alternative to Mycobacterium phlei. Separation of the cell wall components of these strains by multidimensional HPLC and identification of the structures is in progress. The findings so far obtained resemble the findings obtained with Mycobacterium phlei. More detailed peptidomics and proteomics studies to isolate and characterize these structures may shed light on the mechanism of action of these components and lead to preparation of less harmful antitumoral agents. Further study with animal models is also required to show the in vivo effects of these substances.
S ekonder metabolitler, organizma herhangi bir stres durumuyla karşılaştığı zaman faaliyete geçen... more S ekonder metabolitler, organizma herhangi bir stres durumuyla karşılaştığı zaman faaliyete geçen özelleşmiş metabolik yollar tarafından üretilirler. Bu ürünlerin ara metabolizma ürünlerinden farkı, organizmanın büyümesi ve üremesi için mutlak gerekli olmamalarıdır. Buna rağmen organizma için önemli birtakım fonksiyonlar üstlenirler. Atıkların uzaklaştırılması, detoksifikasyon, savunma ve hücreler arası haberleşme bu fonksiyonlar arasındadır . Üretildikleri organizma için üstlendikleri bu çeşitli görevlerin dışında sekonder metabolitler antibiyotik, kemoterapötik, pestisid, immünsüpresif, antilipolitik ajan gibi çok çeşitli farmasötik fonksiyonlara da sahiptir ve bu etkileri nedeniyle yaygın şekilde kullanılmaktadır . Fonksiyonlarındaki çeşitliliğe benzer şekilde, bu bileşikler kimyasal yapıları bakımından da çok büyük çeşitlilik gösterirler. Bu makalede, ribozom dışı yolla sentezlenen oligopeptid yapısındaki sekonder metabolitler (nonribozomal peptidler) ele alınacak ve sentezlenme mekanizması incelenecektir.
To investigate the cytokine-stimulating activity of several Mycobacterium phlei cell wall extract... more To investigate the cytokine-stimulating activity of several Mycobacterium phlei cell wall extracts. Th e bacillus Calmette-Guérin application is the gold standard treatment for some types of superfi cial bladder carcinoma. However, its usage is limited due to its harmful side eff ects. Intensive research has been carried out to fi nd less toxic and more potent therapeutic agents for treatment. Researchers focus on M. phlei for this purpose. Th e cell wall extract of M. phlei is suffi cient for antitumoral activity.
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