Orientador: Marcia Ortiz Mayo Marques / Banca: Beatriz Helena Lameiro de Noronha Sales Maia / Banca: Filipe Pereira Giardini Bonfim / Resumo: Lippia alba (Mill.) N.E.Br, pertencente à família Verbenaceae é uma planta medicinal amplamente distribuída na América do Sul. A composição química do óleo essencial da espécie, a qual derivam suas propriedades terapêuticas mostra-se variável, com divisão em quimiotipos. Entre eles, o quimiotipo citral destaca-se pelas ações calmante e ansiolítica, sendo suas folhas empregadas na medicina popular na forma de chá. Dessa forma, visando o potencial uso econômico de Lippia alba, este estudo teve como objetivos avaliar clones de Lippia alba do quimiotipo citral quanto a produtividade de biomassa e óleo essencial, perfil sensorial do chá e composição química do óleo essencial pelas técnicas de cromatografia gasosa unidimensional (CG) e bidimensional abrangente (CG×CG). Entre os clones, dois mostraram-se promissores para inserção em sistemas de produção, com foco em maior produção de biomassa e óleo essencial. Os perfis químicos dos óleos essenciais dos clones são variáveis entre si. O emprego do sistema CG×CG resultou em maior capacidade de detecção dos constituintes dos óleos essenciais. Ao todo foram identificadas 47 substâncias por CG×CG, contra 26 no CG. A maior sensibilidade e resolução fazem do sistema CG×CG uma importante ferramenta metabolômica no estudo dos constituintes voláteis de Lippia alba. Os clones X6M?C e X6M7 se destacaram quanto as características sensoriais de aroma e sabor, com potencial de inclusão na indústria alimentícia na forma de chá. / Abstract: Lippia alba (Mill.) N.E.Br, from the Verbanaceae family is a medicinal plant widely distributed in the South America. The species's essential oil chemical composition, which derives its therapeutic properties, shows itself as variable, with division in chemotypes. Among them, the citral chemotype highlights itself for the soothing and anxiolytic actions, being its leaves used in the popular medicine in the form of tea. Thus, aiming the potential economic use of the Lippia alba, this work has as objectives evaluate the clones of the citral chemotype of Lippia alba in terms of productivity of biomass and essential oil, sensorial profile and chemical composition of the essential oil by using the one-dimensional gas Chromatography (CG) and comprehensive twodimensional gas chromatography(CGxCG). Among the clone, two stood out as promising to insertion in production systems, with focus on a bigger production of biomass and essential oil. The chemical profiles of the clones's essential oil are variable among themselves. The use of the CGxCG system have resulted in a bigger capacity of identification of the essential oils constituents. Altogether, 47 substances have been identified by CGxCG, against 26 in CG. The better sensibility and resolution are part of the CGxCG, an important metabolomics tool of the volatile constituents of Lippia alba. The X6M?C e X6M7 clones stood out in terms of sensorial features of flavor, with potential of inclusion in the food industry in the form of tea. / Mestre

Through the 1930s, an American woman suffering a broken engagement had the opportunity to sue her erstwhile suitor for breach of promise to marry. Relying on cultural and legal materials, my dissertation uses this now-obsolete cause of action as a lens through which to examine both shifting norms of gender and class during the period from 1890 to 1940 and the means by which Americans expected legal mechanisms to simultaneously shape and respond to socio-cultural changes.

Submitted in partial fulfillment of the requirements for the Degree of Master of Technology in Homoeopathy, Durban University of Technology, Durban, South Africa, 2018. / Research Problem Statement Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS) that involves a combination of emotional and physical symptoms that result in significant functional impairment. PMDD can be debilitating and there are multiple treatment options available, but these are not without side effects. Although complimentary or alternative medicine may be beneficial in treating PMDD, however, there is not enough data available to validate their effectiveness. This study aimed at comparing and determining the efficacy of a homoeopathic mother tincture complex (Vitex agnus castus, Melissa officinalis and Valeriana officinalis) compared to placebo in the management of PMDD. Methodology A sample size of 30 consenting female participants with PMDD who met the inclusion criteria as set out in the Diagnostic and Statistical Manual of Mental Disorders. The duration of the study was three months for each participant. Participants were randomly divided into experimental and placebo groups with three consultations over the study period where Kessler Psychological Distress Scale and Visual Analogue Scale were applied. Non-parametric and inferential analysis of data were performed to analyse and compare the effects of treatment and time on symptoms over the three consultation periods (α.05). Results Results for both scales showed no statistical significance in the interaction between time and treatment. The results showed no statistical differences between the control and experimental group in the management of PMDD. However, the mean value measured in the experimental group were consistently lower than the control. Conclusion The conclusion derived from this study is that the homoeopathic complex studied is not effective in the treatment of PMDD. None of the results showed significant differences between the treatment and the placebo group trials. Further studies are highly recommended in this field. / M

En la actualidad, más son las personas que se preocupan por su cuidado personal y que los productos para este fin provengan de fuentes naturales. Tal es el caso de que muchas marcas de cosméticos, para satisfacer estas nuevas tendencias, crean nuevas líneas de productos de insumos naturales, con certificaciones orgánicas, libre de crueldad animal, entre otras. Simi&Lips nace de la idea de cuatro alumnos de la Universidad Peruana de Ciencias Aplicadas de crear un producto que busca regresar a lo tradicional, es decir, utilizar las propiedades de insumos que se encuentran en la naturaleza para fabricar un bálsamo hidratante para labios artesanal, libre de incipientes, parabenos y metales pesados que a la larga causan repercusiones para la salud. Simi&Lips utiliza insumos que se encuentran certificados como orgánicos entre ellos, el aceite de coco y la mantequilla de cacao, así como también esencias y aceites como la vainilla y la vitamina E, todos ellos reconocidos por sus propiedades humectantes y reparadoras. Simi&Lips busca estar en equilibrio con el medio ambiente y que el cliente lo pueda comprender, es por ello que el concepto se basa en 3 pilares: producto 100% natural, excelente calidad y sobretodo un empaque que contribuye a la reducción de residuos plásticos porque está fabricado en su totalidad de cartón. / Nowadays, people are more concern about personal care and are looking for new products that come from natural sources. Such is the case, that cosmetics industries, to meet this new trend, are creating new product lines with organic inputs with international certifications, free of animal cruelty. Simi&Lips is a four-student’s product idea from Universidad Peruana de Ciencias Aplicadas. This product seeks to go back to the traditional, which means, use the benefits of natural inputs to manufacture a moisturizing lip balm; incipient, heavy metals and parabens free. Simi&Lips uses, on its majority, organic certified products such as cocoa butter and coconut oil, as well as beeswax, vainilla and vitamin E essential oils. All of our lip balm inputs are well-recognized by their moisturizing and repairing properties. Finally, Simi&Lips seeks to be in balance with the environment and that our costumers be aware of it. Our concept is based in a 100% natural product, excellent quality and above all, we package the product in a paperboard tube which contributes to reduce plastic waste. / Trabajo de investigación

La microscopie optique sur substrats antireflets est un outil de caractérisation simple et puissant qui a notamment permis l'isolation du graphène en 2004. Depuis, le domaine d'étude des matériaux bidimensionnels (2D) s'est rapidement développé, tant au niveau fondamental qu'appliqué. Ces matériaux ultraminces présentent des inhomogénéités (bords, joints de grains, multicouches, etc.) qui impactent fortement leurs propriétés physiques et chimiques. Ainsi leur caractérisation à l'échelle locale est primordiale. Cette thèse s'intéresse à une technique récente de microscopie optique à fort contraste, nommée BALM, basée sur l'utilisation originale de couches antireflets très minces (2-5 nm) et fortement absorbantes (métalliques). Elle a notamment pour but d'évaluer les mérites de cette technique pour l'étude des matériaux 2D et de leur réactivité chimique. Ainsi, les différents leviers permettant d'améliorer les conditions d'observation des matériaux 2D ont tout d'abord été étudiés et optimisés pour deux matériaux modèles : l'oxyde de graphène et les monocouches de MoS₂. L'étude de la dynamique de dépôt de couches moléculaires a notamment permis de montrer à la fois l'extrême sensibilité de BALM pour ce type de mesures et l'apport significatif des multicouches antireflets pour l'augmentation du contraste lors de l'observation des matériaux 2D. L'un des atouts principaux de BALM venant de sa combinaison à d'autres techniques, nous nous sommes particulièrement intéressés au couplage de mesures optiques et électrochimiques pour lesquelles le revêtement antireflet sert d'électrode de travail. Nous avons ainsi pu étudier optiquement la dynamique de réduction électrochimique de l'oxyde de graphène (GO), l'électro-greffage de couches minces organiques par réduction de sels de diazonium sur le GO et sa forme réduite (r-GO), ainsi que l'intercalation d'ions métalliques entre feuillets de GO. En combinant versatilité et fort-contraste, BALM est ainsi établi comme un outil prometteur pour l'étude des matériaux 2D et en particulier pour la caractérisation locale et in situ de leur réactivité chimique et électrochimique. / Optical microscopy based on anti-reflective coatings is a simple yet powerful characterization tool which notably allowed the first observation of graphene in 2004. Since then, the field of two-dimensional (2D) materials has developed rapidly both at the fundamental and applied levels. These ultrathin materials present inhomogeneities (edges, grain boundaries, multilayers, etc.) which strongly impact their physical and chemical properties. Thus their local characterization is essential. This thesis focuses on a recent enhanced-contrast optical microscopy technique, named BALM, based on ultrathin (2-5 nm) and strongly light-absorbing (metallic) anti-reflective layers. The goal is notably to evaluate the benefits of this technique for the study of 2D materials and their chemical reactivity. The various levers to improve 2D materials observation were investigated and optimized for two model materials: graphene oxide and MoS₂ monolayers. The investigation of molecular layer deposition dynamic notably showed the extreme sensitivity of BALM for such measurements and the significant contribution of multilayers anti-reflective coatings to enhance contrast during the observation of 2D materials. One of the main assets of BALM comes from its combination to other techniques. We particularly considered the coupling between optical measurements and electrochemistry for which the anti-reflective layer serves as working electrode. We investigated optically the dynamic of electrochemical reduction of Graphene Oxide (GO), the electrografting of organic layers by diazonium salts reduction on GO and its reduced form (rGO), as well as the intercalation of metallic ions within GO sheets. By combining versatility and high-contrast, BALM is established as a promising tool for the study of 2D materials, especially for the local and in situ characterization of their chemical and electrochemical reactivity.

Darbo tikslas: Pagaminti vaistinių melisų ištraukas ir įvertinti jų kokybę. Darbo uždaviniai: 1. Remiantis mokslinės literatūros duomenimis parinkti tinkamą vaistinių melisų skystą vaisto formą, atsižvelgiant į veikliosios medžiagos farmakologines savybes bei parinkti analizės metodus preparatų kokybei įvertinti; 2. Nustatyti ekstrahento (etanolio ir vandens) įtaką melisų ištraukų kokybei; 3. Palyginti ekstrahavimo metodo daromą įtaką vaistinių melisų ištraukų kokybei; 4. Ištirti žaliavos ir ekstrahento santykio daromą įtaką vaistinių melisų ištraukų kokybei. Metodika: 1. Tyrimo objektas – vaistinių melisų ištraukos; 2. Vaistinių melisų vandeninių ir etanolinių ištraukų technologija: a) Ištraukos gamintos klasikinės maceracijos ir perkoliacijos metodais; b) Etanolinės ištraukos gamintos ekstrahuojant ultragarsu ir kokybė vertinama po 20 min., 30 min. ir 40 min. ekstrahavimo; 3. Taikytas spektrofotometrinis metodas pagal Folin – Ciocalteau metodiką, norint nustatyti suminį polifenolinių junginių kiekį pagal KRE; 4. Sauso likučio tyrimas atliktas gravimetriniu metodu; 5. Antimikrobinis aktyvumas nustatytas pagal Ph. Eu. 01/2002, 2.6.12 metodiką. Rezultatai: Spektrofotometriniu metodu nustatyta, kad ekstrahentas turi įtakos veikliųjų junginių išsiskyrimui: didesnis suminis polifenolinių junginių bei sauso likučio kiekis nustatytas, kai ekstrahentu pasirenkamas etanolis, o ne vanduo. Vertinant etanolio koncentraciją nustatyta, kad mažiausiai veikliųjų junginių... [toliau žr. visą tekstą] / Purpose of work: To make and evaluate the quality of Melissa officinalis extracts. Tasks of work: 1. According to the scientific literature to identify an appropriate Balm liquid dosage form according to the pharmacological properties of the active material and the selection of analytical methods for evaluating the quality of products; 2. To set an extraction solvent (ethanol and water) influence on the quality of extracts of Melissa officinalis; 3. To compare extraction method influence on the quality of extracts of Melissa officinalis; 4. To investigate the relationship between the raw material and extraction solvent influence on the quality of extracts of Melissa officinalis. Methods: 1. Object of analysis – extracts of Melissa officinalis; 2. Preparation of an aquous and ethanolic extracts: a) Extracts have been produced by tradicional maceration and percolation methods; b) Ethanol extracts have been produced by extraction by ultrasound. The quality of these extracts has been evaluated after 20, 30, 40 min. 3. Spectrophotometric method (Folin – Ciocalteua method) – common amount of total polyphenolic compounds by p-cumaric acid equivalent has been evaluated; 4. The evaluation of dry residual according to gravimetric analysis has been calculated; 5. Antimicrobial activity by Ph. Eu. 01/2002, 2.6.12 method has been evaluated. Results: By spectrophotometric method it has been evaluated that extrahent has the influence on active compounds emission: higher amount of... [to full text]

The peppermint (Mentha piperita), the salvia (Salvia officinalis), the lemon balm (Melissa oficinalis), the camomile (Matricaria chamomilla) and the valerian (Valeriana officinalis) are herbs with healing effects. Their ethanol extracts are used for food fortification or in a cosmetic industry. Substances contained in herbal extracts were analyzed in this thesis. The extracts were prepared by maceration. Next, they were analyzed by using a gas chromatography and a mass spectrometry. The aim of this thesis was an optimalization of the method used for the analysis of sensorially active substances. Then, herbal extracts were analyzed and concentration of sensorially active substances was determined.

<p>Cilj rada je bio ispitivanje funkcionalnih karakteristika kombuha napitka<br />od melise (<em>Melissa officinalis</em> L.). Antibakterijska aktivnost kombuha<br />napitaka optimalne konzumne i većih kiselosti ispitana je prema<br />bakterijama izolovanim iz hrane i vode za piće. Nosilac antimikrobne<br />aktivnosti je sirćetna kiselina, a na ostale nosioce ukazuje delovanje<br />neutralisane kombuhe i čajnog napitka prema nekim test bakterijama.<br />Spektrofotometrijskom metodom određen je sadržaj ukupnih fenolnih<br />jedinjenja, a HPLC analizom određen je kvalitativni i kvantitativni sastav<br />fenolnih jedinjenja u fermentacionim tečnostima, čajnim i kombuha<br />napicima od melise i crnog čaja. Antioksidativna aktivnost istih uzoraka<br />ispitana je na DPPH i OH radikale ESR spektralnom metodom. Uzorci<br />fermentacione tečnosti i kombuha napitka od melise imali su veću<br />antioksidativnu aktivnost prema oba radikala u odnosu na uzorke sa<br />crnim čajem. Konzumna kombuha od melise imala je veću<br />antioksidativnu aktivnost od čajnog napitka. Aktivne komponente<br />kombuha napitka od melise su verovatno ruzmarinska kiselina i<br />kvercetin. U ispitivanju antiproliferativne aktivnosti konzumnog<br />kombuha napitka i čajnog napitka od melise na tri ćelijske linije humanih<br />karcinoma: HeLa (epitelni karcinom grlića materice), MCF-7<br />(adenokarcinom dojke) i HT-29 (adenokarcinom debelog creva) utvrđeno<br />je da nije do&scaron;lo do stimulacije proliferacije ispitanih ćelijskih linija pri<br />koncentracijama većim od 100 &mu;g/ml. Pored istraživanja biolo&scaron;ke<br />aktivnosti ispitana je mogućnost simultane mlečno-kiselinske i kombuha<br />fermentacije. Dodatkom starter kultura i <em>Lactobacillus spp</em>. izolata u<br />fermentacionu tečnost dolazi do povećanja sadržaja L- i D- mlečne<br />kiseline, iako su ćelije bakterija mlečne kiseline, osim izolata iz kiselog<br />testa (<em>L. hilgardii</em>), pokazale malu otpornost na uslove tokom<br />fermentacije i čuvanja pripremljenih napitaka. Izvr&scaron;ena je i identifikacija<br />bakterija sirćetnog vrenja izolovanih iz lokalnih čajnih gljiva PCR<br />metodom. Dva izolata verovatno pripadaju vrsti <em>Gluconobacter oxydans</em>,<br />a treći vrsti <em>Gluconacetobacter hansenii</em>.</p> / <p>The aim of this study was to investigate functional characteristics of akombucha beverage from lemon balm (<em>Melissa officinalis</em> L.) tea. Antibacterial activity of kombucha beverages with optimum and higheracidities was tested against bacteria isolated from food and drinking water. The main active component of antibacterial activity was acetic acid, while slight activity of neutralized kombucha and unfermented tea against some test bacteria indicated presence of other antibacterial components. Total phenol concentration in unfermented tea samples, fermentation broths and kombucha beverages from lemon balm and black tea was determined spectrophotometrically whereas qualitative and quantitative concentration of polyphenolic compounds was determined by HPLC method. Antioxidant activity on DPPH and hydroxyl radical in the same samples was determined on an ESR spectrometer. Fermentation broth and kombucha beverage from lemon balm had higher antioxidant activity against both radicals than the samples from black tea. Kombucha beverage from lemon balm with optimum acidity had higher antioxidant activity than unfermented lemon balm tea. The main active components of antioxidant activity were probably rosmarinic acid and quercetin. Antiproliferative activity of lemon balm tea and kombucha was measured by sulforhodamine B colorimetric assay on HeLa (cervix epitheloid carcinoma), HT-29 (colon adenocarcinoma), and MCF-7 (breast adenocarcinoma) cell lines. By applying concentrations higher than 100 &mu;g/ml, tested samples did not stimulate proliferation of cell lines. The possibility of simultaneous lactic acid and kombucha fermentation was tested as well. When starter cultures and Lactobacillus spp. isolates were applied, the content of Land D- lactic acid increased during fermentation, although lactic acid bacteria (except <em>L. hilgardii</em> isolated from sour dough) showed low resistance to the conditions during fermentation and beverages storage. Acetic acid bacteria isolated from local tea fungus were identified by PCR method. Two isolates might be <em>Gluconobacter oxydans</em> and one - <em>Gluconacetobacter hansenii.</em></p>

Lippia alba é uma espécie nativa, conhecida como erva cidreira , utilizada na medicina popular para o tratamento de distintas afecções. Estudos farmacológicos atribuem a sua atividade antimicrobiana aos terpenóides presentes no óleo essencial. Considerando a variação na composição de óleos essenciais de L. alba, o presente trabalho teve por objetivo determinar a composição química do óleo essencial de sete acessos de L. alba coletados no sul do Brasil, e avaliar a atividade antimicrobiana dos mesmos sobre um painel de 22 espécies bacterianas e 9 espécies de leveduras. Os óleos essenciais foram extraídos por hidrodestilação e analisados por Cromatografia gasosa e Cromatografia gasosa acoplada a um detector seletivo de massas. A atividade antimicrobiana (Dose de inibição 50% e Concentração inibitória mínima) foi determinada através do método de diluição seriada (0 a 10 mg/ml) em microplacas, com avaliação do crescimento por absorbância a 595nm. Para a determinação de Dose de inibição 50% e Concentração inibitória mínima foram consideradas as concentrações de óleo essencial que reduzidam o crescimento em 50% e 90%, respectivamente. A atividade bactericida e bacteriostática foi deteminada após 3h de tratamento dos microrganismos com a Concentração inibitória mínima pré-determinada para cada óleo. Com base nos seus componentes majoritários, os resultados permitiram caracterizar os sete acessos de L. alba como pertencentes aos quimiotipos: citral, 1,8-cineol/cânfora, linalol, linalol/mirceno/cânfora, carvona/cariofileno, linalol/1,8-cineol/germacreno D, e limoneno. Entre os quimiotipos, o óleo essencial citral exibiu o espectro antimicrobiano mais amplo, inibindo tanto bactérias como leveduras. Óleos com alta concentração de carvona/cariofileno e limoneno foram particularmente eficientes sobre leveduras, enquanto os quimiotipos linalol e linalol/1,8-cineol/germacreno D exibiram atividade inibitória sobre várias bactérias Gram positivas e negativas. Na Concentração inibitória mínima, o quimiotipo citral mostrou ação bactericida sobre leveduras e Salmonella sp. Entretanto, outros óleos apresentaram apenas efeito bacteriostático sobre a maioria dos microrganismos avaliados. Em geral, nossos resultados confirmam a atividade dos óleos essenciais de L. alba sobre microrganismos de importância clínica e industrial, mas apontam a necessidade de avaliação adequada da composição dos mesmos afim de escolher aquele mais efetivo para o controle de um microrganismo específico. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-04T18:06:34Z No. of bitstreams: 1 Dissertacao Fernanda Formolo.pdf: 1268224 bytes, checksum: 2cde3df8d5929f9192359c2c9beb98df (MD5) / Made available in DSpace on 2014-06-04T18:06:34Z (GMT). No. of bitstreams: 1 Dissertacao Fernanda Formolo.pdf: 1268224 bytes, checksum: 2cde3df8d5929f9192359c2c9beb98df (MD5) / Lippia alba is a native species, known as "erva cidreira", currently used in folk medicine for the treatment of several diseases. Pharmacologic studies attributed their antimicrobial activity to the terpenoids present in the essential oils. Considering the variation on essential oil composition among L. alba accessions, the present work aimed to determine the essential oil composition of seven accession of L. alba collected in South Brazil, and to evaluate their antimicrobial activity against a panel of 22 bacterial and 9 yeast species. Essential oils were extracted by hydrodistillation and analyzed by GC and GC/MS. Antimicrobial activity (ID50 and MIC) were determined by a serial dilution method (0 to 10 mg/ml) on microplates with growth evaluation by absorbance at 595nm. For ID50 and MIC determination were considered the essential oil concentrations that reduced microbial growth on 50% and 90%, respectively. Bactericidal and bacteriostatic activities were determined after 3h treatment of the microorganisms with their individual MIC of each essential oil. Based on their main constituents, the results allowed characterizing the seven accessions of L. alba as chemotypes: citral, 1,8-cineol/camphor, linalool, linalool/mircene/camphor, carvone/caryophyllene, linalool/1,8-cineol/germacrene D, and limonene. Among these chemotypes, citral essential oils showed the largest antimicrobial spectrum, inhibiting both bacteria and yeasts. Oils with high concentration of carvone/caryophyllene, and limonene, were particularly effective against yeasts, and oils from chemotypes linalool and linalool/1,8-cineol/germacrene D exhibited inhibitory activity against several Gram positive and negative bacteria. At the MIC, citral showed bactericide effect on yeasts and Salmolella. However, other oils showed just bacteriostatic effects on most microorganisms. In general, our results confirm the activity of L. alba essential oils on both clinical and industrial microorganisms, but point out the necessity to properly evaluate essential oil composition to choose those more effective for the control of a specific microorganism.

Lippia alba é uma espécie nativa, conhecida como erva cidreira , utilizada na medicina popular para o tratamento de distintas afecções. Estudos farmacológicos atribuem a sua atividade antimicrobiana aos terpenóides presentes no óleo essencial. Considerando a variação na composição de óleos essenciais de L. alba, o presente trabalho teve por objetivo determinar a composição química do óleo essencial de sete acessos de L. alba coletados no sul do Brasil, e avaliar a atividade antimicrobiana dos mesmos sobre um painel de 22 espécies bacterianas e 9 espécies de leveduras. Os óleos essenciais foram extraídos por hidrodestilação e analisados por Cromatografia gasosa e Cromatografia gasosa acoplada a um detector seletivo de massas. A atividade antimicrobiana (Dose de inibição 50% e Concentração inibitória mínima) foi determinada através do método de diluição seriada (0 a 10 mg/ml) em microplacas, com avaliação do crescimento por absorbância a 595nm. Para a determinação de Dose de inibição 50% e Concentração inibitória mínima foram consideradas as concentrações de óleo essencial que reduzidam o crescimento em 50% e 90%, respectivamente. A atividade bactericida e bacteriostática foi deteminada após 3h de tratamento dos microrganismos com a Concentração inibitória mínima pré-determinada para cada óleo. Com base nos seus componentes majoritários, os resultados permitiram caracterizar os sete acessos de L. alba como pertencentes aos quimiotipos: citral, 1,8-cineol/cânfora, linalol, linalol/mirceno/cânfora, carvona/cariofileno, linalol/1,8-cineol/germacreno D, e limoneno. Entre os quimiotipos, o óleo essencial citral exibiu o espectro antimicrobiano mais amplo, inibindo tanto bactérias como leveduras. Óleos com alta concentração de carvona/cariofileno e limoneno foram particularmente eficientes sobre leveduras, enquanto os quimiotipos linalol e linalol/1,8-cineol/germacreno D exibiram atividade inibitória sobre várias bactérias Gram positivas e negativas. Na Concentração inibitória mínima, o quimiotipo citral mostrou ação bactericida sobre leveduras e Salmonella sp. Entretanto, outros óleos apresentaram apenas efeito bacteriostático sobre a maioria dos microrganismos avaliados. Em geral, nossos resultados confirmam a atividade dos óleos essenciais de L. alba sobre microrganismos de importância clínica e industrial, mas apontam a necessidade de avaliação adequada da composição dos mesmos afim de escolher aquele mais efetivo para o controle de um microrganismo específico. / Lippia alba is a native species, known as "erva cidreira", currently used in folk medicine for the treatment of several diseases. Pharmacologic studies attributed their antimicrobial activity to the terpenoids present in the essential oils. Considering the variation on essential oil composition among L. alba accessions, the present work aimed to determine the essential oil composition of seven accession of L. alba collected in South Brazil, and to evaluate their antimicrobial activity against a panel of 22 bacterial and 9 yeast species. Essential oils were extracted by hydrodistillation and analyzed by GC and GC/MS. Antimicrobial activity (ID50 and MIC) were determined by a serial dilution method (0 to 10 mg/ml) on microplates with growth evaluation by absorbance at 595nm. For ID50 and MIC determination were considered the essential oil concentrations that reduced microbial growth on 50% and 90%, respectively. Bactericidal and bacteriostatic activities were determined after 3h treatment of the microorganisms with their individual MIC of each essential oil. Based on their main constituents, the results allowed characterizing the seven accessions of L. alba as chemotypes: citral, 1,8-cineol/camphor, linalool, linalool/mircene/camphor, carvone/caryophyllene, linalool/1,8-cineol/germacrene D, and limonene. Among these chemotypes, citral essential oils showed the largest antimicrobial spectrum, inhibiting both bacteria and yeasts. Oils with high concentration of carvone/caryophyllene, and limonene, were particularly effective against yeasts, and oils from chemotypes linalool and linalool/1,8-cineol/germacrene D exhibited inhibitory activity against several Gram positive and negative bacteria. At the MIC, citral showed bactericide effect on yeasts and Salmolella. However, other oils showed just bacteriostatic effects on most microorganisms. In general, our results confirm the activity of L. alba essential oils on both clinical and industrial microorganisms, but point out the necessity to properly evaluate essential oil composition to choose those more effective for the control of a specific microorganism.