As infecções por bactérias representam um grave problema hoje e para o futuro, devido ao fato de que estes microrganismos desenvolvem mecanismos de resistência aos antibióticos ao longo do tempo de uso. A formação de biofilmes também é um fator a ser discutido no cenário atual por estar associado a muitas infecções bacterianas humanas, principalmente àquelas envolvendo dispositivos médicos aumentando assim os riscos de infecções hospitalares. O ácido ursólico (AU) é um triterpeno conhecido por suas atividades biológicas relatadas. Apresenta moderada atividade antibacteriana, porém tem demonstrado importante citotoxicidade frente a algumas linhagens celulares. Em vista disso, neste trabalho se desenvolveu uma série de novas moléculas derivadas do AU com alterações nas posições C-3 e C-28. Quatro moléculas com substituição em C-3 (derivados 2, 3, 4e 5) e uma com substituição em C-3 e C-28 (derivado 6) foram comparadas ao AU (1) quanto a atividade antibacteriana. As cepas utilizadas foram Salmonela Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis e Staphylococcus aureus. Os compostos 3 e 6 apresentaram melhor perfil inibitório de forma geral, onde 3 apresentouse bactericida para S. aureus e S. epidermidis (Gram positivas) e paraP. mirabilis (Gram negativa) apresentou-se bacteriostático. / The ursolic acid (UA) is a triterpene known for their biological activities reported. Thus, become useful techniques semi-synthesis starting from natural products extracted, for example residue industries in order to improve the pharmacological properties decreasing toxicity. The bacterial infections are a serious problem today and in the future due to the fact that these organisms develop resistance mechanisms to antibiotics over time of use. The formation of biofilms is also a factor to be discussed in the current scenario because of being responsible for a very high number of rejections and other prosthetic devices by increasing the risk of nosocomial infections. The AU has a moderate antibacterial activity reported in the literature, but showed significant cytotoxicity against some cell lines. In view of this it developed a series of new molecules derived from AU residues extracted from apples (Mallus domestica) from the juice industry by promoting the so-called green chemistry. The molecules undergo changes in C-3 and C-28. Four molecules with substitution at C-3 (derived from 2, 3, 4 and 5) and one with substitution at C-3 and C-28 (derived 6) were compared with au (1). The strains used in the tests of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration were Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis and Staphylococcus aureus. Compounds 3 and 6 had better inhibitory profile in general, where three presented bactericidal to S. aureus and S. epidermidis (Gram positive) and P. mirabilis (Gram negative) appeared bacteriostatic.

As infecções por bactérias representam um grave problema hoje e para o futuro, devido ao fato de que estes microrganismos desenvolvem mecanismos de resistência aos antibióticos ao longo do tempo de uso. A formação de biofilmes também é um fator a ser discutido no cenário atual por estar associado a muitas infecções bacterianas humanas, principalmente àquelas envolvendo dispositivos médicos aumentando assim os riscos de infecções hospitalares. O ácido ursólico (AU) é um triterpeno conhecido por suas atividades biológicas relatadas. Apresenta moderada atividade antibacteriana, porém tem demonstrado importante citotoxicidade frente a algumas linhagens celulares. Em vista disso, neste trabalho se desenvolveu uma série de novas moléculas derivadas do AU com alterações nas posições C-3 e C-28. Quatro moléculas com substituição em C-3 (derivados 2, 3, 4e 5) e uma com substituição em C-3 e C-28 (derivado 6) foram comparadas ao AU (1) quanto a atividade antibacteriana. As cepas utilizadas foram Salmonela Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis e Staphylococcus aureus. Os compostos 3 e 6 apresentaram melhor perfil inibitório de forma geral, onde 3 apresentouse bactericida para S. aureus e S. epidermidis (Gram positivas) e paraP. mirabilis (Gram negativa) apresentou-se bacteriostático. / The ursolic acid (UA) is a triterpene known for their biological activities reported. Thus, become useful techniques semi-synthesis starting from natural products extracted, for example residue industries in order to improve the pharmacological properties decreasing toxicity. The bacterial infections are a serious problem today and in the future due to the fact that these organisms develop resistance mechanisms to antibiotics over time of use. The formation of biofilms is also a factor to be discussed in the current scenario because of being responsible for a very high number of rejections and other prosthetic devices by increasing the risk of nosocomial infections. The AU has a moderate antibacterial activity reported in the literature, but showed significant cytotoxicity against some cell lines. In view of this it developed a series of new molecules derived from AU residues extracted from apples (Mallus domestica) from the juice industry by promoting the so-called green chemistry. The molecules undergo changes in C-3 and C-28. Four molecules with substitution at C-3 (derived from 2, 3, 4 and 5) and one with substitution at C-3 and C-28 (derived 6) were compared with au (1). The strains used in the tests of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration were Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis and Staphylococcus aureus. Compounds 3 and 6 had better inhibitory profile in general, where three presented bactericidal to S. aureus and S. epidermidis (Gram positive) and P. mirabilis (Gram negative) appeared bacteriostatic.

As infecções por bactérias representam um grave problema hoje e para o futuro, devido ao fato de que estes microrganismos desenvolvem mecanismos de resistência aos antibióticos ao longo do tempo de uso. A formação de biofilmes também é um fator a ser discutido no cenário atual por estar associado a muitas infecções bacterianas humanas, principalmente àquelas envolvendo dispositivos médicos aumentando assim os riscos de infecções hospitalares. O ácido ursólico (AU) é um triterpeno conhecido por suas atividades biológicas relatadas. Apresenta moderada atividade antibacteriana, porém tem demonstrado importante citotoxicidade frente a algumas linhagens celulares. Em vista disso, neste trabalho se desenvolveu uma série de novas moléculas derivadas do AU com alterações nas posições C-3 e C-28. Quatro moléculas com substituição em C-3 (derivados 2, 3, 4e 5) e uma com substituição em C-3 e C-28 (derivado 6) foram comparadas ao AU (1) quanto a atividade antibacteriana. As cepas utilizadas foram Salmonela Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis e Staphylococcus aureus. Os compostos 3 e 6 apresentaram melhor perfil inibitório de forma geral, onde 3 apresentouse bactericida para S. aureus e S. epidermidis (Gram positivas) e paraP. mirabilis (Gram negativa) apresentou-se bacteriostático. / The ursolic acid (UA) is a triterpene known for their biological activities reported. Thus, become useful techniques semi-synthesis starting from natural products extracted, for example residue industries in order to improve the pharmacological properties decreasing toxicity. The bacterial infections are a serious problem today and in the future due to the fact that these organisms develop resistance mechanisms to antibiotics over time of use. The formation of biofilms is also a factor to be discussed in the current scenario because of being responsible for a very high number of rejections and other prosthetic devices by increasing the risk of nosocomial infections. The AU has a moderate antibacterial activity reported in the literature, but showed significant cytotoxicity against some cell lines. In view of this it developed a series of new molecules derived from AU residues extracted from apples (Mallus domestica) from the juice industry by promoting the so-called green chemistry. The molecules undergo changes in C-3 and C-28. Four molecules with substitution at C-3 (derived from 2, 3, 4 and 5) and one with substitution at C-3 and C-28 (derived 6) were compared with au (1). The strains used in the tests of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration were Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Staphylococcus epidermidis and Staphylococcus aureus. Compounds 3 and 6 had better inhibitory profile in general, where three presented bactericidal to S. aureus and S. epidermidis (Gram positive) and P. mirabilis (Gram negative) appeared bacteriostatic.

Corynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to develop because they use different surface receptors, entry mechanisms, enzyme activities, and cytosolic targets. We have found that grape seed extract provides resistance to five different AB toxins: diphtheria toxin (DT), P. aeruginosa exotoxin A (ETA), ricin, Shiga toxin, and cholera toxin (CT). To identify individual compounds in grape seed extract that are capable of inhibiting the activities of these AB toxins, we screened twenty common phenolic compounds of grape seed extract for anti-toxin properties. Three compounds inhibited DT, four inhibited ETA, one inhibited ricin, and twelve inhibited CT. Additional studies were performed to determine the mechanism of inhibition against CT. Two compounds inhibited CT binding to the cell surface and even stripped bound CT off the plasma membrane of a target cell. Two other compounds inhibited the enzymatic activity of CT. We have thus identified individual toxin inhibitors from grape seed extract and some of their mechanisms of inhibition against CT. This work will help to formulate a defined mixture of phenolic compounds that could potentially be used as a therapeutic against a broad range of AB toxins.