We synthesized a series of enediyne containing Combretastatin A-4 analogues and evaluated the growth inhibitory activity of analogues against two human hepatoma cell lines (Hep G2, Hep 3B), two breast cancer cell lines (MDA-MB-231, MCF-7) and human lung cancer cell line (A-549). It was found that compounds 39a, 39d, 39e, 39f and 40a produced growth inhibitory activity for the five human cancer cell lines. Among them, compound 40a showed the best inhibitory activity (IC50 = 0.8 £gM for A-549 and IC50 = 8.53 £gM for Hep 3B) which were comparable to the Combretastatin A-4 (IC50 = 1.57 £gM for A-549 and IC50 = 14.32 £gM for Hep 3B).

A total of 27 new enediyne analogs of combretastatin A-4 (CA-4), with different substituents (Cl, Br, OCH3, SCH3 or N(CH3)2 ) of the aryl A-ring, were designed, synthesized, and evaluated for their growth inhibition activity against human tumor cell lines. Among them, compound 14a showed most significant inhibition activity against Hep3B (0.22 £gM), A-549 (0.49 £gM) and MCF-7 (0.22 £gM), and these activities were greater than CA-4. The enediyne analog 14a may be consider as a new drug candidate worthy of further investigation and development as a potential antitumor agent.

No description available.

We designed a new series of enediyne and their derivatives, and evaluating for their growth inhibition activity against human tumor cell lines. This dissertation is composed of two parts. First, compounds 6c, 6e, 6g and 7g displayed good growth inhibition activity against A549 (non-small-cell lung cancer), AGS (human stomach adenocarcinoma), PC-3 (prostate cancer), BT483 (breast carcinomas), HeLa (human cervical epithelioid carcinoma), OVCA (ovarian cancer cell line), SKHep (hepatocellular carcinoma), H460 (human lung cancer cell line) and SW620 (Human Colorectal Cancer Cell Line), especially compound 7g is better, and its average IC50 is 8.79£gM. Second, compounds 25a and 26 displayed better growth inhibition activity against HeLa (human cervical epithelioid carcinoma), OVCA (ovarian cancer cell line), AGS (human stomach adenocarcinoma) and H460 (human lung cancer cell line), and their average IC50 are10.82 and 11.08 £gM.

A series of anilines and enediynes containing Combretastatin A-4 analogues were synthesized. The growth inhibitory activity of these analogues were evaluated against three human cancer cell lines including human hepatoma (Hep G2), breast cancer (MBA-MB231) and lung cancer (A-549) cell lines. The IC50 values of the synthesized compounds are between 10-5-10-7 £gM. We found that compounds 11e, 12e and 13e were observed good growth inhibitory activity for the three human cancer cell lines, especially for A549 (IC50 = 0.22, 0.40 and 0.16 £gM respectively).

The first section of this work describes the synthesis of a library of novel rhein analogues that are potential anticancer agents. The design of these compounds takes advantage of the ability for rhein to intercalate into DNA and as the incorporation of an alkylating agent, which serves to covalently modify DNA. In three cell lines, these compounds showed potent cytotoxicity with IC50 in the low to mid-μM range. The second project was focused on the development of an efficient synthesis of 6H-Isoindolo[2,1-α]indol-6-one (24), a core structure for a number of biologically active compounds. The approach is metal-free and uses a Beckmann rearrangement followed by an intramolecular cyclization.

The ethanol extract of A. phylicoides was investigated for its antioxidant activity using the DPPH scavenging method. The extract showed good antioxidant results with a EC50 value of 10.64 ± 0.0842 µ/ml. The extract was also tested for antibacterial activity against microorganisms (Staphylococcus aureus, Enterococus faecalis, Bacillus cereus, Bacillus subtilis, Bacillus pumilus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia) commonly known to pose a threat in the wellbeing of man. All tested microorganisms were significantly inhibited by the extract with the MIC values ranging from 3.13 µg/ml to 6.25 µg/ml. Folin-Ciocalteu’s reagent method was used to determine total phenolic content of dried and freshly prepared crude extract of A. phylicoides. Higher total phenolic content (28.28 ± 0.019 mg GAC/100g) and antioxidant activity (EC50, 10.64 ± 0.084 µg/ml) was observed in the dried extract compared to the fresh extract with a TPC value of 23.04 ± 0.003 mg GAC/100g and EC50 of 13.97 ± 0.066 µg/ml. Bioassay-guided fractionation of ethanolic extract from aerial parts of Athrixia phylicoides using silica and sephadex column chromatography led to the isolation of four known flavanoids, 5-hydroxy-6,7,8,3’,4’,5’-hexamethoxyflavon-3-ol (1), 3-0- demethyldigicitrin (2), 5,6,7,8,3’,4’-hexamethoxyflavone (3) and Quecertin (4). Due to the low yield, no further tests were done on compound 3. A DPPH-scavenging assay was performed to evaluate the antioxidant activity of the isolated compounds. All the tested compounds showed potent antioxidant activity with EC50 values ranging from 1.27 to 3.41 µg/ml. Compound 4 showed a higher antioxidant activity (EC50, 1.27 µg/ml) than vitamin C (EC50, 2.66 µg/ml) used as a control. The MIC values of the isolated compounds against tested microorganisms varied from 20 to more than 40 µg/ml. All the tested compounds showed no activity against S. aureus, B. pumilus, K. pneumonia and P. aeruginosa at the highest concentration tested (40 µg/ml). These compounds together with the extract were further analyzed by XTT assay on Vero cells. The extract showed a low toxicity effect on the cells at lower concentrations exhibiting EC50 value of 107.8 ± 0.129 µg/ml. Compound 4 showed minimal toxicity effect on the cells with a EC50 value of 81.38±0.331 µg/ml, compared to Compound 1 and 2 which exhibited EC50 values of 27.91 ± 0.181 µg/ml and 28.92 ± 0.118 µg/ml respectively. The results obtained from this study provide a clear rationale for the medicinal uses of Athrixia phylicoides. / Dissertation (MSc)--University of Pretoria, 2010. / Plant Science / unrestricted

Crop production provides the food and fiber necessary to sustain the world\'s population. Effective weed management is critical to maintaining agricultural productivity. Intensive or continuous use of herbicides that act on the same target site, or are detoxified by similar processes within crops and target weeds frequently results in the development of weeds resistant to a specific herbicide or class of herbicides. Weed resistance due to the extensive use of glyphosate in glyphosate tolerant crop systems has become one of the most serious issues facing agriculture today. Thus PPO-inhibitor herbicides are an alternative mechanism of action that have the potential to mitigate the development of resistant weeds in weed control systems where crop tolerance is sufficient to allow them to be effectively deployed. While there are few reports of weed resistance to PPO-inhibitor herbicides it has not developed to the extent that it is a commercial problem for growers. When used at recommended doses, they typically have favorable regulatory profiles. Furthermore, most of them are highly compatible with no-tillage agriculture. However, PPO-inhibitor herbicides are typically more active on dicots than monocots. This thesis provides information with regards to effectiveness of certain binary mixtures of PPO herbicides as weed control agents. The mixtures showed synergistic effects and could control monocots as Echinochloa crus-galli and volunteer corn besides control the dicots species. Regarding the compounds studied, trifludimoxazin and flumioxazin required less amount of compound to inhibit 50% of PPO2 activity in all plants species tested, while sulfentrazone and saflufenacil, one of the best mixtures in the field, showed that needed bigger concentrations to inhibit 50% of the PPO2 compared to other compounds evaluated.The absorption and translocation of these compounds individually or in mixtures, showed that as single compounds, the absorption was slower in maize than E. crus-galli and there was no difference among the herbicides except trifludimoxazin, that was significantly lower than the other compounds. Saflufenacil was the herbicide that showed the best translocation out of treated leaf point, while trifludimoxazin has not shown any translocation out of leaf treated. In mixtures, the compounds showed some differences in absorption and translocation, which it was variable according to species studied. Some traits of PPO-tolerant were also evaluated in Arabidopsis thaliana which indicates potential traits to be developed in crops of interest. / Agricultura é responsável por fornecer alimento e fibras necessárias para sustentar a população mundial. Controle de plantas daninhas é essencial para obter uma boa produtividade. O uso intensivo de herbicidas que age no mesmo sitio de ação ou são detoxificados por processos similares pelas plantas daninhas resulta geralmente no desenvolvimento de plantas daninhas resistentes a um herbicida específico ou à uma classe de herbicidas. A resistência de plantas daninhas devido ao uso de culturas tolerantes à glifosato tem se tornado um dos mais sérios problemas na agricultura. Inibidores da PPO pode ser uma ferramenta para mitigar o desenvolvimento de plantas daninhas resistentes. Há poucos relatos de plantas daninhas resistentes a este mecanismo de ação. Quando aplicados na dose recomendada, apresentam perfil toxicológico favorável e além disso, a maioria dos herbicidas deste grupo são compatíveis com plantio direto. No entanto, são mais eficientes em dicotiledôneas do que em monocotiledôneas. O objetivo dessa tese foi fornecer informações em relação a associação binária de herbicidas inibidores da PPO no controle de plantas daninhas. As associações mostraram efeito sinérgico no controle de Echinochloa crus-galli e milho voluntário, além do controle de dicotiledôneas. Avaliou-se também a atividade de alguns inibidores da PPO na inibição de 50% da enzima PPO2 e observou-se que para inibir 50% da PPO2 necessitou de menor quantidade de trifludimoxazin e flumioxazin em todas as plantas testadas, enquanto que sulfentrazone e saflufenacil, que associados apresentaram a melhor eficácia nos ensaios de campo, mostraram que precisar de maiores concentrações para inibir a PPO2 comparada aos outros produtos. A absorção e translocação destes produtos, isolados ou em mistura, mostraram que a absorção foi mais lenta em milho do que em E. crus-galli. Os herbicidas apresentaram comportamentos similares, sendo absorvidos quase 95% até 72 horas após aplicação, com exceção do trifludimoxazin, que foi significativamente mais lento que os outros. Saflufenacil foi o herbicida que apresentou melhor translocação na folha aplicada, enquanto trifludimoxazin não apresentou nenhuma translocação. Em relação às associações, os produtos mostraram diferenças na absorção e translocação, variando conforme as plantas daninhas estudadas. Alguns eventos tolerantes a inibidores da PPO foram avaliados em Arabidopsis thaliana e indicaram como potenciais eventos para ser desenvolvidos nas culturas de interesse.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-12-21T10:59:07Z No. of bitstreams: 2 Dissertação - Karla Márcia da Silva Braga - 2016.pdf: 1581456 bytes, checksum: cbaf9c07e17608723ba37f6ee325896f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-12-27T12:57:39Z (GMT) No. of bitstreams: 2 Dissertação - Karla Márcia da Silva Braga - 2016.pdf: 1581456 bytes, checksum: cbaf9c07e17608723ba37f6ee325896f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-12-27T12:57:39Z (GMT). No. of bitstreams: 2 Dissertação - Karla Márcia da Silva Braga - 2016.pdf: 1581456 bytes, checksum: cbaf9c07e17608723ba37f6ee325896f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Osteosarcoma is a mesenchymal high mortality tumor of dogs and men. Cytotoxicity assays employing tropical plants have been performed in order to identify possible active compounds able to inhibit neoplastic cells proliferation. The fruits from the Cerrado, Center-west Brazil’s diversity-rich, predominant vegetation, are well-known by the general public but very little is known about their pharmacological properties. Thus, the aim of this study was to verify the cytotoxic activity of the ethanoic extract / O osteossarcoma é uma neoplasia de origem mesenquimal de elevada mortalidade em cães e no homem. Ensaios de citotoxicidade com plantas tropicais têm sido realizados para identificar possíveis princípios ativos medicinais capazes de inibir a proliferação de células tumorais. O cerrado é a vegetação predominante da região Centro-Oeste do Brasil, rico em biodiversidade, no qual frutos, como o pequi (Caryocar brasilense) são amplamente conhecidos, porém pouco explorados quanto a suas propriedades farmacológicas. Neste contexto, o objetivo deste estudo foi verificar a atividade citotóxica do extrato etanólico da casca de pequi em células de osteossarcoma canino em cultura estabelecida, obtidas do banco de linhagens celulares, subcultivadas e submetidas ao tratamento com o EECP em três diferentes concentrações e três diferentes tempos de exposição. O tratamento que inibiu de forma mais eficiente o crescimento celular foi o grupo no qual foram adicionados 10µl do EECP por 72 horas, resultando em crescimento de 28,20% em relação ao controle, ou seja, uma inibição de 71,80%. A menor média do IC50 foi de 155,2 µg/mL, no tratamento que recebeu 10µl do EECP por 72 horas. Com o cálculo das frações de sobrevivência presumiu-se que o crescimento celular, após o tratamento, foi menor (3,33 %) no grupo tratado por 72 horas com a concentração de 10 µl. Com base nos resultados obtidos, concluiu-se que o extrato etanólico da casca de pequi (Caryocar brasiliense) possui efeito citotóxico sobre as células de osteossarcoma canino, promovendo redução da viabilidade celular de forma dependente do tempo de exposição e da concentração do extrato utilizada

Crop production provides the food and fiber necessary to sustain the world\'s population. Effective weed management is critical to maintaining agricultural productivity. Intensive or continuous use of herbicides that act on the same target site, or are detoxified by similar processes within crops and target weeds frequently results in the development of weeds resistant to a specific herbicide or class of herbicides. Weed resistance due to the extensive use of glyphosate in glyphosate tolerant crop systems has become one of the most serious issues facing agriculture today. Thus PPO-inhibitor herbicides are an alternative mechanism of action that have the potential to mitigate the development of resistant weeds in weed control systems where crop tolerance is sufficient to allow them to be effectively deployed. While there are few reports of weed resistance to PPO-inhibitor herbicides it has not developed to the extent that it is a commercial problem for growers. When used at recommended doses, they typically have favorable regulatory profiles. Furthermore, most of them are highly compatible with no-tillage agriculture. However, PPO-inhibitor herbicides are typically more active on dicots than monocots. This thesis provides information with regards to effectiveness of certain binary mixtures of PPO herbicides as weed control agents. The mixtures showed synergistic effects and could control monocots as Echinochloa crus-galli and volunteer corn besides control the dicots species. Regarding the compounds studied, trifludimoxazin and flumioxazin required less amount of compound to inhibit 50% of PPO2 activity in all plants species tested, while sulfentrazone and saflufenacil, one of the best mixtures in the field, showed that needed bigger concentrations to inhibit 50% of the PPO2 compared to other compounds evaluated.The absorption and translocation of these compounds individually or in mixtures, showed that as single compounds, the absorption was slower in maize than E. crus-galli and there was no difference among the herbicides except trifludimoxazin, that was significantly lower than the other compounds. Saflufenacil was the herbicide that showed the best translocation out of treated leaf point, while trifludimoxazin has not shown any translocation out of leaf treated. In mixtures, the compounds showed some differences in absorption and translocation, which it was variable according to species studied. Some traits of PPO-tolerant were also evaluated in Arabidopsis thaliana which indicates potential traits to be developed in crops of interest. / Agricultura é responsável por fornecer alimento e fibras necessárias para sustentar a população mundial. Controle de plantas daninhas é essencial para obter uma boa produtividade. O uso intensivo de herbicidas que age no mesmo sitio de ação ou são detoxificados por processos similares pelas plantas daninhas resulta geralmente no desenvolvimento de plantas daninhas resistentes a um herbicida específico ou à uma classe de herbicidas. A resistência de plantas daninhas devido ao uso de culturas tolerantes à glifosato tem se tornado um dos mais sérios problemas na agricultura. Inibidores da PPO pode ser uma ferramenta para mitigar o desenvolvimento de plantas daninhas resistentes. Há poucos relatos de plantas daninhas resistentes a este mecanismo de ação. Quando aplicados na dose recomendada, apresentam perfil toxicológico favorável e além disso, a maioria dos herbicidas deste grupo são compatíveis com plantio direto. No entanto, são mais eficientes em dicotiledôneas do que em monocotiledôneas. O objetivo dessa tese foi fornecer informações em relação a associação binária de herbicidas inibidores da PPO no controle de plantas daninhas. As associações mostraram efeito sinérgico no controle de Echinochloa crus-galli e milho voluntário, além do controle de dicotiledôneas. Avaliou-se também a atividade de alguns inibidores da PPO na inibição de 50% da enzima PPO2 e observou-se que para inibir 50% da PPO2 necessitou de menor quantidade de trifludimoxazin e flumioxazin em todas as plantas testadas, enquanto que sulfentrazone e saflufenacil, que associados apresentaram a melhor eficácia nos ensaios de campo, mostraram que precisar de maiores concentrações para inibir a PPO2 comparada aos outros produtos. A absorção e translocação destes produtos, isolados ou em mistura, mostraram que a absorção foi mais lenta em milho do que em E. crus-galli. Os herbicidas apresentaram comportamentos similares, sendo absorvidos quase 95% até 72 horas após aplicação, com exceção do trifludimoxazin, que foi significativamente mais lento que os outros. Saflufenacil foi o herbicida que apresentou melhor translocação na folha aplicada, enquanto trifludimoxazin não apresentou nenhuma translocação. Em relação às associações, os produtos mostraram diferenças na absorção e translocação, variando conforme as plantas daninhas estudadas. Alguns eventos tolerantes a inibidores da PPO foram avaliados em Arabidopsis thaliana e indicaram como potenciais eventos para ser desenvolvidos nas culturas de interesse.