Chemical and Enantioselective Analysis of the Essential Oils from Different Morphological Structures of Ocotea quixos (Lam.) Kosterm

The traditional Ecuadorian spice Ishpingo, characterized by a strong cinnamon-like aroma, is constituted by the dry cupules of Amazonian species Ocotea quixos. Nevertheless, bark and leaves also present aromatic properties and are sometimes used as substitutes. In the present study, the essential oils, distilled from these morphological structures, are comparatively analyzed for their chemical and enantiomeric compositions. A total of 88 components were identified with 2 orthogonal GC columns, whereas 79, corresponding to more than 94%, were also quantified with at least 1 column. Major compounds were (E)-methyl cinnamate in cupules (35.9–34.2%), (E)-cinnamaldehyde in bark (44.7–47.0%), and (E)-cinnamyl acetate (46.0–50.4%) in leaves. For what concerns the enantioselective analysis, 10 chiral terpenes and terpenoids were detected, of which 6 were present as enantiomeric pairs in at least 1 essential oil, the others being enantiomerically pure. Both quantitative and enantioselective analyses were submitted to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), where their results confirmed significative difference among the three products.

Variability of the Chemical Composition of the Essential Oil from the Amazonian Ishpingo Species (Ocotea quixos)

Ocotea quixos (Lam.) Kosterm. is an aromatic tree native to Ecuador, whose leaves are used to prepare aromatic beverages to which different health benefits are attributed. In this study, Ocotea quixos leaves were collected in the Amazon region in different environmental conditions and subjected to hydrodistillation to isolate the essential oil. The collection variables used were type of soil, amount of shade, and height; in addition, the presence of twig and leaf age and moisture were used as variables. Chemical composition was analyzed by means of gas chromatography equipped with a flame ionization detector and gas chromatography coupled to mass spectrometry. A wide variety of chemical compositions were detected in the samples. In total, forty-seven compounds were identified, which represented between 97.17% and 99.89% of the total composition. The constituents were mainly grouped into aliphatic sesquiterpene hydrocarbons (33.03–55.89%), other compounds (8.94–47.83%), and oxygenated monoterpenes (1.97–39.66%). The main constituents were found to be (E)-cinnamyl acetate (5.96–41.65%), (E)-methyl cinnamate (0.38–37.91%), and trans-caryophyllene (8.77–37.02%). The statistical analysis suggested the existence of two essential oil chemotypes and a direct correlation between environmental conditions and chemical composition of the essential oils.

Skrining Senyawa dari Tanaman Rhodomyrtus tomentosa (Aiton) Hassk terhadap SARS-CoV-2 ORF3a

The ORF3a protein from SARS-CoV has functions in terms of ion channel activity, modulates the trafficking properties of SARS-CoV spike (S) protein, increases fibrinogen expression in pulmonary epithelial cells, and induces apoptosis. So that research is needed to overcome the ORF3a experiment. The method in this research uses the computational screening method with autodok4 software. The results of this study resulted in free binding energy between Hassk Rhodomyrtus tomentosa (Aiton) and ORF3a compounds, namely: α-tocopherol-quinone (-5.86); blumeatin (-4.98); methyl cinnamate (-4.44); myricetin (-4.49); naringenin (-4.93); quercetin (-4,9); rhodomyrtone (-6); rhodomyrtosone B (-7.11); rhodomyrtosone C (-6.77); tetrahydroxyflavanone (-4.91); α-tocopherol A (-6.72); verimol K (-4.89); watsonianone A (-7.55). Based on the data obtained, the ligand with the most potential due to the stability of the bond is watsonianone A.

Isolation and Characterization of Antioxidant Active Compounds from the Leaves and Flowers of Manilkara hexandra (Roxb.)

Fractionation and chromatographic purification of the crude methanol extract of air-dried leaves of Manilkara hexandra (Roxb) yielded five compounds p-methoxy methyl cinnamate (1), p-hydroxymethylcinnamate (2), 2,5-dihydroxybenzaldehyde (3), gallic acid methyl ester (4) and quercetin-3-O-β-D-glucoside (isoquercitrin) (5), whereas air-dried flowers yield phenylethylpalmitate (6). The structures of these compounds were confirmed using spectroscopic data, comparison with literature data and co-TLC comparison with authentic samples. To the best of our knowledge compounds 1, 3, 5 and 6 were isolated for the first time from this plant. Constituents of the plant were known to be active against Staphylococcus aureus and Staphylococcus epidermidis. Comparative antioxidant activity of compounds along with the crude extract and fractions were assessed using four different assay protocols. These compounds show moderate activity in the antioxidant assay systems. Present results rationalize the usage of the leaves and flower paste as bathing aid as suggested in the folklore literature to maintain a dynamic balance of skin microflora.

Phylogenetic re-examination of the genus Conocephalum Hill. (Marchantiales: Conocephalaceae)

Inter-relationship among the cryptic species in the genus Conocephalum Hill was studied using rbcL + rps4 sequences as well as morphological features. Samples used in this study originated from 1) the long-cultivated strains from Europe, North America, and Asia used for previous allozymes and molecular studies and 2) newly gathered plants mainly from Japan and Taiwan used for both molecular and morphological study. For the C. conicum/ salebrosum complex, a total of six species were confirmed, including a new species previously recognized as R type or Chemotype III (Toyota 1994, Kim et al. 2001 Miwa et al 2009). The R type has unique volatile component and morphological features; presence of Methyl cinnamate in natural conditions and absence of mucilage cavity in the central part of thallus. As for the C. japonicum complex, three cryptic species formerly recognized by allozymes and molecular analyses were confirmed. These three species are remotely distant from all the members of the C. conicum/ salebrosum complex. Conocephalum japonicum is here reinstated in the genus Sandea Lindb., as Sandea japonica Steph. ex Yoshin.