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ABSTRACT: Leaf area is an important growth variable in agricultural crops and the leaf is the main variable of interest in the tobacco industry. So, the aim of this scientific research was to estimate the Burley tobacco leaf area by linear dimensions of the leaves and to determine which mathematical model is more adequate for this purpose. Two experiments were carried out with Burley tobacco, cultivar DBH 2252, in 2016/2017 and 2018/2019 agricultural years, respectively, in the municipalities of Itaqui and Vanini - RS - Brazil. In 600 leaves were measured length (L), width (W), length×width product (LW), length/width ratio (L/W) and determined the real leaf area (LA). Four hundred and fifty leaves were separated to generate models of the leaf area as a function of linear dimension and the other 150 leaves were used for model's validation. The power model LA = 0.5037LW1.04435 (R² = 0.9960) is the most adequate for Burley tobacco 'DBH 2252' leaf area estimation. Alternatively, the models LA=2.0369W1.8619 (R²=0.9796) and LA=0.1222L2.2771 (R²=0.9738) based on width and length, respectively, can be used when only one leaf dimension is measured.
RESUMO: A área foliar é uma importante variável de crescimento em culturas agrícolas, sendo a folha a principal variável de interesse na indústria do tabaco. Assim, o objetivo deste estudo científico foi determinar a área foliar de tabaco tipo Burley por meio de dimensões lineares da folha e determinar qual modelo matemático é mais adequado para essa finalidade. Dois experimentos foram conduzidos com tabaco tipo Burley, cultivar DBH 2252, nos anos agrícolas de 2016/2017 e 2018/2019, respectivamente, nos municípios de Itaqui e Vanini, RS, Brasil. Em 600 folhas foram medidos o comprimento (L), a largura (W), o produto comprimento×largura (LW), a razão comprimento/largura (L/W) e determinada a área foliar real (LA). Foram separadas 450 folhas para a geração de modelos de estimativa de área foliar em função da dimensão linear e 150 folhas foram utilizadas para a validação dos modelos. O modelo LA = 0,5037LW1,04435 (R² = 0,9960) é adequado para a estimação da área foliar de tabaco Burley cultivar DBH 2252. Alternativamente, os modelos LA=2,0369W1,8619 (R²=0,9796) e LA=0,1222L2,2771 (R²=0,9738) baseados na largura e comprimento, respectivamente, podem ser utilizados quando apenas uma dimensão da folha é medida.
ABSTRACT
Objective To find the new biological compounds, the research of the chemical constituents in the leaves of Nicotiana tabacum had been carried out. Methods The chemical constituents in the leaves of N.tabacum were isolated by silica gel, Sephadex LH-20 column chromatographies, and RP-HPLC methods. The structures of isolations were detected by using various spectroscopic techniques, including extensive 1D and 2D NMR techniques. Results Two C-alkylated flavones were isolated from 95% ethanol extract of plant, which identified as 2’-hydroxy-7-(3-hydroxypropyl)-8-methoxy-flavone (1) and tabaflavone A (2). Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. Conclusion Compound 2 is isolated from the leaves of N.tabacum for the first time. Compound 1 is a new compound named orientalflavone A. Compounds 1 and 2 also show good anti-MRSA activity with MIC90 value of (38 ± 4) and (33 ± 3) μg/mL, respectively.
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RESUMO: O processo de pelotização pode afetar a qualidade das sementes por ocasião da semeadura, por isso, para avaliar o efeito desse processo na qualidade das sementes, foram utilizadas sementes de duas cultivares de tabaco 'CSC 467' e 'CSC 07', coletadas em diferentes etapas do processo de beneficiamento e pelotização: 1) sementes nuas não beneficiadas; 2) sementes nuas beneficiadas; 3) sementes pelotizadas; 4) sementes pelotizadas e coloridas. Para avaliação da qualidade das sementes nessas diferentes etapas, foram realizados os seguintes testes: germinação, primeira contagem de germinação, índice de velocidade de germinação, teste de emergência e índice de velocidade de emergência. Posteriormente, as sementes foram armazenadas por seis e doze meses e sua qualidade avaliada pelos mesmos testes e determinações. O processo de pelotização avaliado não influencia na germinação final de sementes de tabaco, mas atrasa o processo germinativo. As sementes de tabaco das cultivares 'CSC 467' e 'CSC 07' mantêm sua qualidade durante os 12 meses de armazenamento em câmara fria, com temperatura de 10°C e umidade relativa de 50%.
ABSTRACT: The pelletizing process may affect the quality of seeds during sowing. In order to evaluate the effect of this process on seed quality it was used seeds from three tobacco cultivars, 'CSC 467' and 'CSC 07' collected in different processing and pelletizing process stages: 1) non processed nude seeds; 2) processed nude seeds; 3) pelletized seeds; 4) pelletized and colored seeds. For the evaluation of seed quality in these different stages it was performed the following tests: Germination, First Count of Germination, Germination Speed Index, Initial and Final Stand (Emergence) and Emergence Speed Index. Posteriorly, seeds were stored for six and twelve months and their quality was evaluated by the same tests and determinations. The evaluated pelletizing process does not influence final germination of the tobacco seeds, but delays the germination process. Tobacco seeds from cultivars 'CSC 467' and 'CSC 07' maintain their quality during the 12 months of storage in cold chamber with temperature of 10oC and relative humidity of 50%.
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Objective: To study the cembranoid diterpenes from the leaves of Nicotiana tabacum. Methods: The cembranoid diterpenes were isolated and purified by silica gel and preparative HPLC, and their structures were elucidated on the basis of their physicochemistry properties and spectral data. Results: Five cembranoid diterpenes were obtained from the ethanol extract of the leaves of N. tabacum and identified as (1S,2E,4R,6R,7E)-4,6,11-trihydroxy-1-isopropyl-4,8-dimethylpentadeca-2,7-dien-12-one (1), (1S,2E,4R,6R,7E,11E)-2,7,11-cembradiene-4,6-diol (2), (1S,2E,4S,6R,7E,11E)-2,7,11-cembradiene-4,6-diol (3), (1S,2E,4R,6R,7E, 11S)-2,7,12 (20)-cembratriene-4,6,11-triol (4), and (1S,2E,4S,6R,7E,11S)-2,7,12(20)-cembratriene-4,6,11-triol (5). Conclusion: Compound 1 is a new chain-like cembranoid diterpene named nicotiaditerpene A.
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Objective To investigate the biotransformation of furannoligularenone by cell suspension cultures of Nicotiana tabacum. Methods Furannoligularenone was added to the medium of the suspension cells of N. tabacum after precultured for 10 d, then they were co-cultured for another 4 d. The biotransformed products were detected with HPLC and isolated by various chromatographic methods. The chemical structures of biotransformed products were elucidated on the basis of their physicochemical pro-perties and spectroscopic data. Otherwise, the influence of co-cultured time on conversion ratio was investigated either. Results The substrate, furannoligularenone (Ⅰ), was successfully biotransformed by N. tabacum cultured cells. Two products, 3-oxo-eremophila-1, 7(11)-dien-12, 8-olide (Ⅱ) and 3-oxo-8-hydroxyeremophila-1, 7(11)-dien-12, 8-olide (Ⅲ) were obtained. After co-cultured for 5 d, the mole conversion ratio of the substrate reached the highest (53.1%). Conclusion It's the first report on biotransformation of furannoligularenone by N. tabacum cultured cells.