Antimicrobial Abietane-Type diterpenoids from Plectranthus punctatus

Abdissa Ayana N, Frese M, Sewald N. Antimicrobial Abietane-Type diterpenoids from Plectranthus punctatus. Molecules. 2017;22(11): 1919.Four new para-benzoquinone containing abietane-type diterpenoids (1–4) along with thirteen known diterpenoids (5–17) were isolated from the roots of Plectranthus punctatus. The structures of the compounds were established by detailed spectroscopic analyses and comparison with literature data. The compounds were tested for their antibacterial and cytotoxic activity and showed significant inhibitory activity against all bacterial strains used, with compounds 6, 8, 10, and 11 showing an inhibition zone for Staphylococcus warneri even greater than the reference drug, gentamycin

Cytotoxic Compounds from Aloe megalacantha

Abdissa Ayana N, Gohlke S, Frese M, Sewald N. Cytotoxic Compounds from Aloe megalacantha. Molecules. 2017;22(7): 1136.Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1), aloesaponarin III (2), 10-O-methylchrysalodin (3) and methyl-26-O-feruloyl-oxyhexacosanate (4)—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM) being the most active compound

Bioactive secondary metabolites from new endophytic fungus Curvularia. sp isolated from Rauwolfia macrophylla.

Kaaniche F, Hamed A, Abdel-Razek AS, et al. Bioactive secondary metabolites from new endophytic fungus Curvularia. sp isolated from Rauwolfia macrophylla. PLoS ONE. 2019;14(6): E0217627.Over the last decades, endophytic fungi represent a new source of pharmacologically active secondary metabolites based on the underlying assumption that they live symbiotically within their plant host. In the present study, a new endophytic fungus was isolated from Rauwolfia macrophylla, a medicinal plant from Cameroon. The fungus showed a highest homology to Curvularia sp. based on complete nucleotide sequence data generated from the internal transcribed spacer (ITS) of ribosomal DNA region. Large scale fermentation, working-up and separation of the strain extract using different chromatographic techniques afforded three bioactive compounds: 2'-deoxyribolactone (1), hexylitaconic acid (2) and ergosterol (3). The chemical structures of compounds 1-3 were confirmed by 1 and 2D NMR spectroscopy and mass spectrometry, and comparison with corresponding literature data. Biologically, the antimicrobial, antioxidant activities and the acetylcholinesterase inhibitory of the isolated compounds were studied

Anthraquinones from the Roots of Kniphofia insignis and Evaluation of Their Antimicrobial Activities

Sequential extraction using a cold maceration method and column chromatographic separation of the roots Kniphofia insignis headed to the isolation of three anthraquinones: one monomeric anthraquinone (1) and two dimeric anthraquinones (2 and 3). It was further purified by Sephadex LH-20 and recrystallized. The structures of these compounds were established based on the spectroscopic analyses including NMR (1H-NMR and 13C-NMR and infrared) and comparison with reported literatures. In an in vitro antimicrobial assay of the crude extracts, the isolated compounds were made against four bacterial strains (S. aureus ATCC 25923, B. subtilis ATCC 6633, E. coli ATCC 35218, and P. aeruginosa ATCC 27853) and Fusarium spp. fungal strain. In the crude extracts of chloroform, substantial antimicrobial activity was seen with the highest activity against B. subtilis (16 mm) and E. coli (22 mm). Meanwhile, compound 1 has a better zone of inhibition with 14 mm against P. aeruginosa, whereas compound 2 showed better activity (13 mm) against Fusarium spp. fungal strain

Phytochemical investigation of <i>Aloe pulcherrima</i> roots and evaluation for its antibacterial and antiplasmodial activities

<div><p>Medicinal plants with documented traditional uses remain an important source for the treatment of a wide range of ailments. Evidence shows that majority of the Ethiopian population are still dependent on traditional medicine. <i>Aloe pulcherrima</i> Gilbert & Sebsebe is one of the endemic <i>Aloe</i> species traditionally used for the treatment of malaria and wound healing in central, Southern and Northern part of Ethiopia. The aim of the current study was, therefore, to isolate active compounds from roots of <i>A</i>. <i>pulcherrima</i> and evaluate for their antibacterial and antiplasmodial activities using standard test strains. Bioassay-guided sequential extraction and column chrom-atographic separation were employed for the isolation of bioactive pure compounds. The structures of the compounds were determined by 1D and 2D NMR spectro-scopic techniques. Disk diffusion method was employed to evaluate the antibacterial activities of the isolated compounds against four bacterial strains specifically (<i>Staphylococcus aureus</i> ATCC 25923, <i>Bacillus subtilis</i> ATCC 6633, <i>Escherichia coli</i> ATCC 35218, <i>Pseudomonas aeruginosa</i> ATCC 27853). The malaria SYBR Green I-based <i>in vitro</i> assay technique was used for <i>in vitro</i> antiplasmodial activity evaluation of the compounds against chloroquine resistant (D6) and -sensitive (W2) strains of <i>P</i>. <i>falciparum</i>. Three compounds, chrysophanol, aloesaponarin I and aloesaponarin II were isolated from the acetone extracts of roots of <i>A</i>. <i>pulcherrima</i>. Evaluation of antibacterial activities revealed that aloesaponarin I and aloesaponarin II had significant activities against all the bacterial strains with inhibition zone diameters ranging from 18–27 mm as compared to the reference drug (gentamicin), which displayed inhibition zone diameter ranging between 20 mm (<i>B</i>. <i>subtilis</i>) and 25 mm (<i>P</i>. <i>aeruginosa</i>). The isolated compounds showed moderate <i>in vitro</i> antiplasmodial activity against both chloroquine resistant (W2) -sensitive (D6) strains. Isolation of chrysophanol, aloesaponarin I and aloesaponarin II from roots of <i>A</i>. <i>pulcherrima</i> is the first report of its kind. The finding could be used for further comprehensive evaluation of the isolated compounds for their antibacterial and antimalarial activities besides consideration of the same for potent drug development.</p></div

<i>In vitro</i> antibacterial and antiplasmodial activities of compounds isolated from <i>A</i>. <i>pulcherrima</i>.

<p><i>In vitro</i> antibacterial and antiplasmodial activities of compounds isolated from <i>A</i>. <i>pulcherrima</i>.</p

Chemical constituents of the roots of Kniphofia isoetifolia Hochst. and evaluation for antibacterial activity

Context: The genus Kniphofia Moench, with species close to 70, is traditionally used to treat wide ranges of ailments including menstrual pains, infertility, abdominal cramps, wounds, malaria, chest complaint and hepatitis B. Kniphofia isoetifolia, an endemic species in Ethiopia, is known for wounds healing applications in Southern Ethiopia. Aims: To investigate the roots of Kniphofia isoetifolia and evaluate the extracts and its constituents for antibacterial activity. Methods: The roots of Kniphofia isoetifolia was extracted with chloroform/methanol (1:1 v/v), and the resulting crude extract was partitioned between EtOAc/H2O. The ethyl acetate extract afforded four compounds after chromatographic purification, and their identification was based on spectroscopic analyses. The extracts and pure compounds were evaluated for in vitro antibacterial activity on four bacterial strains namely Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis. Results: The purification of the extract of roots of Kniphofia isoetifolia resulted in identification of four compounds (1 – 4). This is the first report on the phytochemical investigation of Kniphofia isoetifolia and occurrence of compound 1 in the genus Kniphofia. The extracts and isolates demonstrated antibacterial activity. The Compound 3 in some cases demonstrated comparable zone of inhibition with gentamycin. Conclusions: This is the first report of the occurrence of naphthoquinone derivative, 3,5,8-trihydroxy-2-methylnaphthalene-1,4-dione (1) in the genus Kniphofia which appears to have a chemotaxonomic significance to narrow down the gap between Alooideae and Asphodeloideae subfamily. The two dimeric anthraquinones (3, 4) showed strong activity with highest zone of inhibition recorded for asphodeline (3) against E. faecalis

Cytotoxic Compounds from Aloe megalacantha

Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1), aloesaponarin III (2), 10-O-methylchrysalodin (3) and methyl-26-O-feruloyl-oxyhexacosanate (4)—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM) being the most active compound

¹H (500 MHz) and ¹³C (125 MHz) NMR Spectral data for compounds 1, 2 and 3 isolated from root of <i>A</i>. <i>pulcherrima</i>.

<p>¹H (500 MHz) and ¹³C (125 MHz) NMR Spectral data for compounds 1, 2 and 3 isolated from root of <i>A</i>. <i>pulcherrima</i>.</p

MnOx-Coffea arabica Husk and Catha edulis Leftover Biochar Nanocomposites for Removal of Methylene Blue from Wastewater

In this study, we investigated the use of manganese oxide-biochar nanocomposites (MnOx-BNC), synthesized from coffee husk (CH) and khat leftover (KL) for the removal of methylene blue (MB) from wastewater. Pristine biochars of each biomass (CH and KL) as well as their corresponding biochar-based nanocomposites were synthesized by pyrolyzing at 300°C for 1 h. The biochar-based nanocomposites were synthesized by pretreating 25 g of each biomass with 12.5 mmol of KMnO4. To assess the MB removal efficiency, we conducted preliminary tests using 0.2 g of each adsorbent, 20 mL of 20 mg·L−1 MB, pH 7.5, and shaking the mixture at 200 rpm and for 2 h at 25°C. The results showed that the pristine biochar of CH and KL removed 39.08% and 75.26% of MB from aqueous solutions, respectively. However, the MnOx-BNCs removed 99.27% with manganese oxide-coffee husk biochar nanocomposite (MnOx-CHBNC) and 98.20% with manganese oxide-khat leftover biochar nanocomposite (MnOx-KLBNC) of the MB, which are significantly higher than their corresponding pristine biochars. The adsorption process followed the Langmuir isotherm and a pseudo-second-order model, indicating favorable monolayer adsorption. The MnOx-CHBNC and MnOx-KLBNC demonstrated satisfactory removal efficiencies even after three and six cycles of reuse, respectively, indicating their potential effectiveness for alternative use in removing MB from wastewater