Hechtia glomerata Zucc: Phytochemistry and Activity of Its Extracts and Major Constituents Against Resistant Bacteria

Abstract

Hechtia glomerata Zucc. is used both as a source of food and in ethnomedicine to treat various diseases derived from bacterial infections such as bronchitis, laryngitis, nephritis, whooping cough, urethritis, and sepsis. There are no previous reports about its chemistry and biological activities. Therefore, the aims of this study were to identify components from organic and aqueous extracts of H. glomerata and test the extracts and major isolate compounds against resistant bacteria. Hexane, CHCl3/MeOH, and aqueous extracts were prepared and analyzed by different chromatographic techniques. Structural elucidation was carried out by NMR spectroscopy and X-ray diffraction. The antibacterial activities of extracts, phytochemicals, and semisynthetic derivatives against resistant bacteria were determined by the broth micro-dilution method. From the hexane extract nonacosane (1), hexatriacontanyl stearate (2), hexacosanol (3), oleic acid (4), and β-sitosterol (5) were isolated and characterized. From the CHCl3/MeOH extract, p-coumaric acid (6), margaric acid (7), caffeic acid (8), daucosterol (9), and potassium chloride (10) were isolated and characterized. A total of 58 volatile compounds were identified by GC-MS from the hexane extract and two solids were isolated from the CHCl3/MeOH extract. The UPLC-QTOF-MS analysis of the aqueous extract allowed the identification of 55 polar compounds. Hexane and aqueous extracts showed antibacterial activity against ESBL Escherichia coli, and three strains of Klebsiella pneumoniae ESBL, NDM-1 +, and OXA-48 with MIC values of 500 µg/mL. The CHCl3/MeOH extract was devoid of activity. The activity of phytocompounds and their semisynthetic derivatives toward resistant bacteria was weak. The most active compound was β-sitosterol acetate, with a MIC value of 100 µg/mL against carbapenem-resistant A. baumannii. This is the first report of the secondary metabolites of H. glomerata Zucc. and the activity of its extracts and major pure compounds against resistant bacterial strains.

Cytotoxic Fractions from Hechtia glomerata Extracts and p-Coumaric Acid as MAPK Inhibitors

“…Therefore, we further investigated it because of its broad composition, which might reveal interesting compounds. The extract was fractionated by column chromatography (CC) [ 10 ], and its pooled fractions were tested to identify compounds that were responsible for the observed activities.…”

“…p -CA was previously isolated and purified through several column chromatography separations of the CHCl 3 /MeOH (1:1) extract. The pure compound was then structurally characterized by 1 H and 13 C nuclear magnetic resonance [ 10 ]. Furthermore, p -CA was identified as one constituent of the cytotoxic fraction, with an estimated 6.05% of the total weight.…”

“…028029) was deposited at the herbarium of the Faculty of Biology, Universidad Autónoma de Nuevo León. The plant name can be found at [ 10 ].…”

“…In our previous studies [ 10 , 11 ], the chemical composition of H. glomerata was determined by gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) analyses of hexane, CHCl 3 /MeOH, and aqueous crude extracts. We also evaluated activity of the extracts and pure compounds against resistant bacteria.…”

“…Therefore, we tested its cytotoxicity. Two cell lines, MCF7 and PC3, were selected, based on cytotoxic activity that was exerted by the extract from which p -CA was isolated, as reported in our previous works [ 10 , 11 ]. The mechanism of action of phenolic acid, which causes apoptosis, was previously reported for some cell lines and has been associated with the production of intracellular reactive oxygen species (ROS) [ 14 ].…”