The calyxes of Hibiscus sabdariffa are used in traditional medicine around the world. However, quality assurance protocols and chemical variability have not been previously analyzed. In the present study, chemical characterization of a set of samples of H. sabdariffa calyxes commercialized in Colombia was accomplished with the aim to explore the chemical variability among them. Chemometrics-based analyses on the data obtained from the HPLC-UV-DAD-derived profiles were then performed. Thus, the pre-processed single-wavelength data were subjected to principal component analysis (PCA). The PCA-derived results evidenced different groups which were well-correlated to the corresponding total phenolic and total anthocyanin contents. Multi-wavelength chromatographic (HPLC-UV-DAD surfaces) data were additionally examined via parallel factor analysis (PARAFAC) as data reduction method and the obtained loadings were subsequently submitted to PCA and orthogonal partial least squares discriminant analysis (OPLS-DA). Results were thus consistent with those from single-wavelength data. PCA loadings were employed to determine those chemical components responsible for the data variance and OPLS-DA model, constructed from PARAFAC loadings, and indicated differentiation according total anthocyanin contents among samples. The present chemometric analysis therefore demonstrated to be an excellent tool for differentiation of H. sabdariffacalyxes according to their chemical composition.

Las infecciones causadas por hongos continúan siendo un problema de salud pública en la actualidad. De hecho, existen diversos programas para el descubrimiento de fármacos enfocados en la búsqueda de estructuras plantilla. El mapeo virtual junto con docking molecular constituye una alternativa importante para encontrar potenciales estructuras promisorias. Mediante herramientas de docking molecular se pueden definir nuevos blancos terapéuticos para combatir diversas infecciones. Por tanto, se llevó a cabo el estudio del acoplamiento molecular a treinta y dos compuestos de origen natural, empleando la N-miristoil transferasa (NMT) como blanco enzimático antifúngico. De los compuestos ensayados, alcaloides, flavonoides, xantonas y quinonas mostraron interacción media más fuerte con la NMT que los terpenos, cumarinas y fenólicos. Particularmente, la afinidad encontrada para un alcaloide aporfínico, un flavonoide prenilado y dos xantonas resultó comparable con la encontrada para un inhibidor sintético reportado. En el presente trabajo se demostraron varias interacciones tanto hidrofóbicas como hidrofílicas mediante diversas herramientas computacionales. Los resultados encontrados permiten establecer tres posibles estructuras promisorias para el desarrollo de fármacos antifúngicos, aunque se requiere aún de estudios de relación estructura-actividad.

Fungal infections currently remain as a common problem in public health. Actually, drug discovery programs are oriented to the searching for lead structures. Virtual screening and molecular docking constitute great alternatives in order to find hit compounds. Novel infection targets can also be defined and employed together with molecular docking tools in drug discovery programs. Thus, thirty-two natural compounds were docked within the active site of N-myristoyl transferase (NMT) as antifungal enzyme target. From tested compounds, alkaloids, flavonoids, xanthones, and quinones exhibited strongest mean interaction with NMT than terpenoids, coumarins and phenolics. Particularly, affinities for one aporphine alkaloid, a prenylated flavonoid and two xanthones resulted to be comparable with that of previously reported synthetic inhibitor. Several hydrophobic and polar contacts were demonstrated by comparing different computational tools. The present results let to establish three possible lead structures to develop antifungal drugs although subsequent SAR analyses are still required.

23 crude ethanolic extracts of Piper plants were analyzed by combining HPLC fingerprints and chemometric methods including principal component analysis (PCA), hierarchical clustering analysis (HCA) and parallel factor analysis (PARAFAC). All statistical analysis were carried out both with and without previous preprocessing by counting with alignment of the fingerprints by correlation optimized warping (COW) and several normalization methods. Normalization processes of autoscaling, range scaling and vast scaling resulted to be the better offering the most relevant information. Both direct two-way methods (PCA and HCA) and HCA after data minimization employing a three-way method (PARAFAC) were demonstrated to be useful in the establishment of chemical composition relationships among Piper samples, and resulting in agreement with phylogenic relationships previously reported in literature to some Piper species.

The essential oil was obtained by steam distillation from fruits of Iryanthera ulei Warb. growing in Colombia. The oil was analyzed by GC/FID and GC/ MS. The main components were a-muurolol (13.2%), spathulenol (12.1%), a-cadinol (7.8%), guaiol (4.0%), oplopanone (3.7%), 1,10-diepi-cubenol (3.4%) and limonene (3.3%) constituting a sesquiterpene-type enriched mixture. In addition, oil was tested for its antimicrobial activity against some Gram-positive and Gram-negative bacteria by means of a modified agar-well diffusion method. S. aureus strain was found to be the most sensitive microorganism.