Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains. Keywords: Plectranthus ornatus, diterpenes, ent-clerodanes, bacteriostatic IntroductionThe genus Plectranthus L'Her (Lamiaceae, subfamily Nepetoideae, tribe Ocimeae, subtribe Plectranthinae) comprises approximately 300 species largely distributed over the African, Asian and Australian continents. 1 Plectranthus is a large genus well known by its diversity of ethnobotanical uses, being especially indicated to treat digestive disorders, skin diseases, infections and respiratory problems. 2 In general, are rich source of essential oils, terpenoids and phenol compounds. 3 Pharmacological properties such as anti-inflammatory, 4 antioxidant, 5 antimicrobial, 6 anti-tumoral 7 and diuretic 8 have been demonstrated for several isolated compounds from Plectranthus, corroborating with its larger medicinal uses.Plectranthus ornatus Codd (syn. Coleus comosus Hochst. ex Gurke) is a perennial and aromatic herb, widespread around the new world. 9 In the northeast of Brazil, P. ornatus, popularly known as "malva santa" or "boldo miúdo", is cultivated as a very important medicinal plant, indicated as analgesic and particularly to treat gastric disorders. 10 Several antimicrobial labdanes, ent-clerodanes, and halimane-type diterpenoids have been previously isolated from P. ornatus. 11 As part of a multidisciplinary program, where the efforts are devoted to study medicinal plants or congeners, in order to unveil their pharmacological or biological properties, herein we describe the isolation and characterization of five new diterpenes derivatives together with six known compounds from the aerial parts of cultivated specimens of P. ornatus, as well as the results of pharmacological and biological assays with the isolated secondary metabolites (Figure 1). Ávila et al. 1015 Vol. 28, No. 6, 2017 Experimental General experimental proceduresOptical rotations were measured on a PerkinElmer 341 digital polarimeter. Infrared (IR) spectra were obtained on a PerkinElmer FT-IR spectrum 1000 spectrometer. Accurate mass spectra were acquired on a liquid chromatography-mass spectrometry ion-trap and time-of-flight (LCMS-IT-TOF, Shimadzu) spectrometer. Nuclear magnetic resonance (NMR) spectra were performed either on Bruker DPX-300 or DRX-500 spectrometers. Open column chromatography (CC) were carried out wit...
Resumo. O presente trabalho apresenta o resultado da vivência de estudantes do ensino médio da cidade de Quixadá-CE com atividades de aprendizagem cooperativa aplicadas ao ensino de química. Quatro técnicas distintas de aprendizagem cooperativa (jigsaw, método dos pares, fila cooperativa e teste cooperativo) foram empregadas como estratégias de ensino-aprendizagem. Os resultados obtidos foram analisados no que diz respeito à apreensão dos conteúdos e observou-se um ambiente menos competitivo e mais colaborativo entre os estudantes, contribuindo assim para o desenvolvimento de aprendizagem significativa. O trabalho inclui descrição das técnicas de aprendizagem cooperativa, apresentação de todo o percurso metodológico utilizado, bem como a avaliação dos resultados.
Two new polyunsaturated 3,4-epoxy-heneicosane derivatives named as epoxy-lobophorene A and epoxy-lobophorene B were isolated from the brown alga Lobophora variegata, in addition to nine known compounds. The structures of the new compounds were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). The isolated compounds were submitted to antiproliferative assays against the human colon cancer cell line HCT-116, human metastatic prostate cancer PC-3M, murine metastatic melanoma B16-F10 and murine fibroblast cell line L929 and also tested as antibacterial. Both 3,4-epoxy lobophorene A and 3,4-epoxy lobophorene B depicted moderate antiproliferative effect against cell lines. None of them showed antibacterial activity.
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