Eliana Schwartz Tavares

Análise do óleo essencial de folhas de três quimiotipos de Lippia alba (Mill.) N. E. Br. (Verbenaceae) cultivados em condições semelhantes

A composicao do oleo essencial de Lippia alba apresenta variacao quantitativa e qualitativa, levando a separacao em quimiotipos. O trabalho tem como objetivo analisar o oleo essencial de folhas de tres quimiotipos de Lippia alba, provenientes de diferentes regioes do Brasil, cultivados em condicoes semelhantes, a fim de verificar se as diferencas na composicao do oleo devem-se a fatores ambientais ou a variacao genetica infraespecifica e se a floracao influencia o rendimento e a composicao do oleo. Os quimiotipos produtores de citral, carvona e linalol, foram denominados Lippia alba 1, 2 e 3, respectivamente. Os oleos essenciais foram extraidos por hidrodestilacao de folhas e analisados por cromatografia com fase gasosa e cromatografia com fase gasosa acoplada ao espectrometro de massas. O melhor rendimento foi obtido das plantas no estagio vegetativo. A composicao do oleo essencial manteve-se inalterada para os tres quimiotipos apos cultivo em condicoes semelhantes e tambem nao variou qualitativamente durante o crescimento vegetativo e floracao. Os dados obtidos reforcam a ideia que as diferencas na composicao do oleo essencial dos quimiotipos refletem variacoes genotipicas entre as plantas e que a extracao de oleo essencial de L. alba deve ser efetuada na fase de crescimento vegetativo, quando e maior o rendimento do oleo e a porcentagem dos componentes majoritarios.

Screening of Central and South American plant extracts for antimycobacterial activity by the Alamar Blue test

Forty eight ethanolic crude extracts and fractions (hexane, dichloromethane, ethyl acetate and n-butanol) from ten Brazilian plants (Leguminosae, Monimiaceae and Verbenaceae), 1 from Costa Rica (Verbenaceae) and 1 from Argentina (Verbenaceae) were screened for anti-mycobacterium activity against Mycobacterium tuberculosis (ATCC-27294H37Rv), by the Alamar Blue test, at a fixed concentration of 100 µg/mL. Out of the forty eight, seven were active at this concentration, corresponding to Lantana trifolia (hexane and dichloromethane extracts from leaves), Vitex cooperi (methanol:water, 1:1 extract from barks), Lippia lacunosa (hexane and dichloromethane extracts from leaves) and Lippia rotundifolia (hexane and dichloromethane extracts from leaves), all from the Verbenaceae family.

Increased antioxidant activity and changes in phenolic profile of Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) specimens grown under supplemental blue light.

Antioxidant compounds protect plants against oxidative stress caused by environmental conditions. Different light qualities, such as UV‐A radiation and blue light, have shown positive effects on the production of phenols in plants. Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) is used for treating wounds and inflammations. Some of these beneficial effects are attributed to the antioxidant activity of plant components. We investigated the effects of blue light and UV‐A radiation supplementation on the total phenol content, antioxidant activity and chromatographic profile of aqueous extracts from leaves of K. pinnata. Monoclonal plants were grown under white light, white plus blue light and white plus UV‐A radiation. Supplemental blue light improved the antioxidant activity and changed the phenolic profile of the extracts. Analysis by HPLC of supplemental blue‐light plant extracts revealed a higher proportion of the major flavonoid quercetin 3‐O‐α‐l‐arabinopyranosyl (1→2) α‐l‐rhamnopyranoside, as well as the presence of a wide variety of other phenolic substances. These findings may explain the higher antioxidant activity observed for this extract. Blue light is proposed as a supplemental light source in the cultivation of K. pinnata, to improve its antioxidant activity.

Kinetin Enhanced Linalool Production by in vitro Plantlets of Lippia alba

Abstract Lippia alba Mill. N. E. Br (Verbenaceae) is an aromatic shrub widely distributed in Brazil where the infusion of its leaves is used in folk medicine due to sedative and antispasmodic properties. This study presents data about quantitative variation of the major volatile constituents of the linalool producing L. alba chemotype. The volatiles were extracted by solid phase microextraction (SPME) from plants cultivated in soil (mother plants), from in vitro plantlets grown in Murashige & Skoog (MS) medium and from in vitro plantlets grown in MS medium with growth regulators. The content of α-pinene, (Z)-3-hexenyl acetate and α-gurjunene was greater in the mother plants than in plantlets, whereas the content of sabinene, myrcene, 1,8-cineole and p-mentha-1,5,8-triene was lower. The addition of 0.23 μM of IAA to the medium significantly enhanced sabinene and myrcene contents. The addition of 0.92 μM of kinetin significantly increased the 3(S)-(+)-linalool level.

Cromatografia em camada fina de extratos de três quimiotipos de Lippia alba (Mill) N.E.Br. (erva-cidreira)

The present work shows the thin layer chromatography of the essential oils, the ethanolic extract and the dicloromethane extract obtained from leaves of three chemotypes of Lippia alba. The chemotypes were denominated chemotype I, II and III for the differences in the majoritary compound of their essential oils: citral, carvone and linalol, respectivelly. The oil and the extracts were compared with standards of citral, carvone and linalool. Ethanol and dicloromethane can be used for extraction since both extracts have similar cromathografic profiles. There was no diference between extracts of fresh and dried leaves. The results show a fast and eficcient identification of the three chemotypes by thin layer cromatoghraphy.

Effects of Supplemental UV-A on the Development, Anatomy and Metabolite Production of Phyllanthus tenellus Cultured In Vitro

Phyllanthus tenellus is widely used for its antiviral, analgesic and hepatoprotective properties. Although the production of several chemical classes of secondary metabolites is influenced by UV radiation, particularly phenolic compounds, we also know that UV radiation can result in anatomical and developmental damage. However, the morphological, anatomical and phytochemical changes in response to UV‐A exposure are generally understudied in the Phyllanthaceae. Therefore, we evaluated the effects of UV‐A radiation on plant development and leaf anatomy, as well as the production of secondary metabolites and the contents of carotenoids and chlorophylls a and b, in P. tenellus. To accomplish this, in vitro cultures of P. tenellus were maintained for 60 days under white light (WL) and WL plus UV‐A radiation. Results showed different phenotypic responses under additional UV‐A, such as high phenolic metabolite production, increasing dimensions of abaxial epidermis and thickness of palisade parenchyma. Compared to plants cultured under WL, UV‐A radiation caused damage to plant morphogenesis, including a reduced number of branches and shoots, consequently reducing the rate of proliferation. On the other hand, geraniin, ellagic acid and carotenoid contents increased after UV‐A exposure, indicating that this light source is an important resource for inducing phenolic compounds.

Ultraviolet-B radiation effects on phenolic profile and flavonoid content of Kalanchoe pinnata

Ultraviolet-B radiation is an important abiotic factor that can stimulate the production of secondary metabolites, including polyphenolic compounds. Kalanchoe pinnata (Crassulaceae) is a medicinal plant popularly used in Brazil for treating wounds and inflammation. This species is rich in phenolic compounds, which could account for some of its biological activities, including antileishmanial, antihypertensive and antibacterial properties. We investigated the effects of supplemental UV-B radiation on the phenolic profile, antioxidant activity and total flavonoid content of leaves of K. pinnata. Plants were grown under white light (W - control) and supplemental UV-B radiation (W+UVB). Supplemental UV-B radiation enhanced the total flavonoid content of the leaf extracts, without affecting the antioxidant activity or yield of extracts. Analysis by TLC and HPLC of W and W+UVB leaf extracts revealed quantitative and qualitative differences in their phenolic profiles. W+UVB extracts contained a higher diversity of phenolic compounds and a larger amount of quercitrin, an important bioactive flavonoid of this species. This is the first report of the use of ImageJ® program to analyze a TLC visualized by spraying with NP-PEG reagent. UV-B radiation is proposed as a supplemental light source in K. pinnata cultivation in order to improve its flavonoid composition.

Comparative anatomy of leaves of Kalanchoe pinnata and K. crenata in sun and shade conditions, as a support for their identification

Kalanchoe pinnata (Lam.) Pers. and K. crenata (Andrews) Haw., Crassulaceae, are popularly used in the treatment of many diseases. Their biological activities, such as anti-leishmaniasis and analgesic, can be useful in phytotherapy. Both species are often misidentified as the other, because of their similar popular uses and names, and the similar external morphology of the leaves. We investigated the existence of anatomical characters that will permit correct identification of the species grown in shade and in sun conditions. We also contribute with new observations on the leaf anatomy of K. pinnata and K. crenata. Fixed (FAA70) leaves were used, and their sections were embedded in Leica historesin. Hydathodes were observed in both species, and for the first time were anatomically described in K. crenata. The species showed anatomical differences in relation to the presence of epidermal idioblasts only in K. crenata, the different pattern of distribution of subepidermal idioblasts, and the presence of leaf buds only in K. pinnata.

Standardized production of Phyllanthus tenellus Roxb. by plant tissue culture

Exigencies as ethic plant raw material are part of the needs of modern phytotherapy. Micropropagation offers opportunities to obtain mass propagation of superior genotypes in short time. This study aimed to develop a protocol of direct and indirect organogenesis of Phyllanthus tenellus Roxb. Nodal segments from plantlets obtained by in vitro germination were subcultured in modified Murashige and Skoog medium added with different plant growth regulators: IAA (indole-3-acetic acid), IBA (indole-3-butyric acid), GA 3 (3-giberelic acid) and KIN (kinetin). The highest proliferation rate was obtained using the combinations: IBA, KIN + GA 3 (3.5 mg L -1 ) and IBA + KIN (2.4 mg L -1 ). Rooting was intensified after 40 days, reaching 100% for all media with indole-3-butyric acid. Addition of 2,4 dichlorophenoxyacetic acid (2,4D) provided the best results for production of friable calli. Acclimatization was 100% effective for plantlets cultured in control medium, with decrease in survival rate in grown plantlets from media added with growth regulators.

Influence of blue light on the leaf morphoanatomy of in vitro Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae).

Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) (air plant, miracle leaf) is popularly used to treat gastrointestinal disorders and wounds. Recently, the species was tested to treat cutaneous leishmaniasis with successful results. This medicinal activity was associated with the phenolic fraction of the plant. Blue light induces biosynthesis of phenolic compounds and many changes in anatomical characteristics. We studied the effects of supplementary blue light on the leaf morphology of in vitro K. pinnata. Plants cultured under white light (W plants) only and white light plus blue light (WB plants) show petioles with plain-convex section, amphistomatic leaf blades with simple epidermis, homogeneous mesophyll with densely packed cells, and a single collateral vascular bundle in the midrib. W plants have longer branches, a larger number of nodes per branch, and smaller leaves, whereas WB plant leaves have a thicker upper epidermis and mesophyll. Leaf fresh weight and leaf dry weight were similar in both treatments. Phenolic idioblasts were observed in the plants supplemented with blue light, suggesting that blue light plays an important role in the biosynthesis of phenolic compounds in K. pinnata.