This work describes the first chemical study on the metabolic profile of three geopropolis samples from Melipona fulva, M. compressipes, and M. paraensis collected in the Amazonian region. The samples were submitted to solvent extractions. The silylated hexane extracts were submitted to GC-MS analysis and tentatively identified mainly the presence of triterpenes, steroids, fatty acids, and alcohols. The chemical profile of M. fulva of and M. compressipes geopropolis are similar. However, cholesterol, triacontanol, and palmitic acid are the main compounds in M. fulva; in M. compressipes, palmitic acid, linoleic acid, and oleic acid are predominant. The chemical profile of the M. paraensis sample is entirely different once more than 60% of the extract comprises lupenone and triacontanol. The CHCl3 soluble fraction of the MeOH extract of the M. paraensis geopropolis was submitted to chromatographic techniques, and it afforded cycloartenol, 24-methylene-cycloartenol, lupeol, α- and β-amirins, and 7-O-methylaromadendrin. The MeOH extract of this sample presents antimicrobial activities against strains of Streptococcus mutans, S. sobrinus, and S. aureus (MIC of 15.6-62.5 µg mL−1 and MBC of 62.5-1000 µg mL−1). The M. fulva and M. compressipes geopropolis were not active in this test.

Agathisflavone is a natural biflavone with restricted occurrence in plants. This biflavone presents several biological activities and can be important to developing new drugs. Obtaining such a molecule on a large scale for in vivo tests is a challenge. To date, there are no reports regarding its synthesis; thus, it is important to improve and develop methods for the purification of this bioactive compound from natural sources. Previous studies indicated that the leaves of Poincianella pyramidalis (Leguminosae) had agathisflavone predominantly. However, obtaining this compound requires some steps of chromatographic procedures and extraction with organic solvents. This paper compares four procedures for the purification of agathisflavone from its leaves, two by traditional chromatographic techniques and by complexation with inorganic bases. The purification in the automatic flash chromatography in two steps provides a high-yield extraction; the two procedures using alkaline extraction and the traditional method reduced to three steps provided the compound with similar yields. The biflavone was identified by TLC, and HPLC analysis showed that it was isolated with > 99% of purity. Thus, the applied methodologies provided the purification of this compound employing less volume of solvents, the number of chromatographic column procedures, and time-consuming, with increased yields.

This work describes the isolation of pure bergenin from Peltophorum dubium roots with good yields and its further derivatization through Williamson synthesis. The alkyl derivatives of the bergenin were identified by nuclear magnetic resonance and mass spectrometry data analysis. Among them, three derivatives were reported for the first time herein, 8,10-dihexyl-bergenin, 8,10-didecyl-bergenin, and 8,10-ditetradecyl-bergenin, along with three previously reported ones (8,10-dimethylbergenin, 8-methylbergenin, 8,10-dioctyl-bergenin). Most derivatives of the bergenin displayed moderate cytotoxicity against Artemia salina, except the 8,10-dihexyl-bergenin (lethal concentration doses for 50% (LC50) = 70.55 µg mL-1). The antimicrobial assay showed that all derivatives selectively inhibited the Gram-positive bacteria Staphylococcus aureus, and two of them (8,10-dihexyl-bergenin and 8,10-didecyl-bergenin) had promising activities (minimum inhibitory concentration (MIC) = 5.1-6.2 µmol L-1). In addition, bergenin displayed interesting inhibition on acetylcholinesterase (half maximal inhibitory concentration (IC50) = 141.19 ± 0.41 µmol L-1), while its semi-synthetic derivatives displayed modest activity. Our results revealed that the antibacterial activity of bergenin could be greatly improved through its structural modification.

This work describes the importance of using renewable sources in experimental classes for undergraduate students, as well as to spread the ideas of using biomass wastes as a source of products of interest. Therefore, in the proposed experiment, citrus fruit peel waste was employed to obtain pure flavonoids by extraction and recristalization. These procedures are important to reveal to students how bioactive products can be easily obtained from natural sources. In this way, naringin and hesperidin could be efficiently extracted from grapefruit (Citrus x. paradisi L.) and common orange (Citrus sinensis L. osbeck) peel wastes, respectively, using simple alcohols as solvents.

This work describes the chemical composition of MeOH seeds and flowers extracts of Tapirira guianensis, a known tree that occurs in the Brazilian Atlantic forest. The CH2Cl2 soluble fraction of seeds extract was submitted to chromatographic procedures to obtain a mixture of new alkenyl dihydrobenzofuranoids which were identified as 2-[(10’Z)-dodec-10’-enyl]-dihydro-1-benzofuran-5-ol, 2-[(10’Z)-tridec-10’-enyl]-dihydro-1-benzofuran-5-ol e 2-[(10’Z)-pentadec-10’-enyl]-dihydro-1-benzofuran-5-ol (1 - 3) besides β-sitosterol. From the EtOAc soluble fraction of flowers MeOH extract quercetin, quercitrin and gallic acid were obtained by chromatographic techniques. The fatty acid composition of oils from leaves and seeds were also determinate and the leaves’ oil is composed by 63.94% of saturated and 36.04% of unsaturated fatty acids while in the seeds the oil present 42.13% of saturated and 57.87% of unsaturated. All compounds and derivatives were identified by their spectrometric data analysis. The brine shrimp test of the extracts showed the seed CH2Cl2 and the EtOAc and BuOH soluble fractions of the flowers were actives and, the alkyl phenols are the responsible for this moderate activity. The antioxidant tests of the extracts indicated EtOAc soluble fraction of MeOH extract of flowers showed better results possibly due the presence of flavonoids and gallic acid.

Spondias mombin L. is a Brazilian tree belonging to the family Anacardiaceae and popularly known as “cajá”, the genus is well known by the various exotic fruit species such as “siriguela” (S. purpurea), “umbu” (S. tuberosa) and “umbu-cajá” (S. bahiensis). It presents commercial importance to the locals especially due the small juice fruit industries and the seeds are often discarded as waste after pulping. Despite the regional importance, even today there is little information on the chemical composition of these fruits. Thus, the dichloromethane extract of the waste seeds of S. mombin was subjected to different chromatographic fractionation allowing the isolation of a main triglyceride identified as 1,3-dioleoyl-2-linoleoyl glycerol, two new alkyl phenols named 1-hydroxyl-3-[(Z)-10’-octadecenyl]-benzene and 1-hydroxyl-3-[(Z)-10’-docosenyl] benzene, and a mixture of phytosteroids. The seed’s fatty acid profile and the cytotoxicity of the oils and isolated compounds were also determinated employing BST. The alkenylphenol mixture present some toxicity (CL50 215,4 µg mL-1) in this test.

ABSTRACT The profile of volatile organic compounds, the glandular and non-glandular trichomes of Plectranthus ornatus, obtained by in vitro cultivation, was evaluated in plants grown in Murashide and Skoog medium supplemented with benylaminopurine at 4.5, 9.0, and 18.0 µM + naphthaleneacetic acid at 5.37 µM, kinetin at 4.7, 9.3 and 18.5 µM + naphthaleneacetic acid (5.37 µM) or Murashide and Skoog 0 medium (as a control). Scanning Electron Microscopy was performed on samples of the third leaf node of the 90 days old plants obtained from treatment with 4.5 or 9.0 µM benylaminopurine, and 4.7 or 9.3 µM kinetin. Headspace Solid Phase Micro-Extraction of the 30, 60 and 90 days old in vitro plants permitted to determinate by GC/MS the composition comprised of 62 compounds. The data were analyzed using Principal Component Analysis and Hierarchical Clustering Analysis and, the major constituents of these oils after treatment and aging were monoterpenes and sesquiterpenes. Morphoanatomical analysis of trichomes, by Scanning Electron Microscopy, enabled the identification of non-glandular trichomes and four types of glandular trichomes, which comprised capitate and peltate glandular trichomes that were distributed on both sides of the leaf. We observed that the regulators influenced qualitative and quantitative profiles of the volatile organic compounds and the number and distribution of hairs on the leaf surface.