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The phytochemical investigation of Caralluma quadrangula aerial parts yielded six new pregnane glycosides, quadrangulosides A–F (1–6), in addition to nine known pregnane glycosides and three known flavone glycosides.

Chemical constituents of Raphanus sativus Linn. roots were extracted and tested for their toxicity against adults and second instar nymphs of A. gossypii under laboratory conditions. The most effective fraction against both adults and nymphs was methylene chloride fraction with LC50 values of 386.63 and 309.43 ppm, followed by ethyl acetate fraction with LC50 values of 394.9 and 334.37 ppm then petroleum ether fraction with LC50 values of 636.2 and 424.56 ppm, for adults and nymphs, respectively. Also, the volatile components of each fraction were qualitatively and quantitatively identified and characterized by GC/MS technique. Moreover, the impact of the sub-lethal concentrations of R. sativus roots extracts on transaminases and alkaline phosphatase of A. gossypii was studied. Great inhibition of all tested enzymes activity was observed. This suggested the high potency of R. sativus roots extracts as environmentally friendly alternatives of traditional insecticides. Chemical constituents of Raphanus sativus Linn. roots were extracted and tested for their toxicity against adults and second instar nymphs of A. gossypii under laboratory conditions. The most effective fraction against both adults and nymphs was methylene chloride fraction with LC50 values of 386.63 and 309.43 ppm, followed by ethyl acetate fraction with LC50 values of 394.9 and 334.37 ppm then petroleum ether fraction with LC50 values of 636.2 and 424.56 ppm, for adults and nymphs, respectively. Also, the volatile components of each fraction were qualitatively and quantitatively identified and characterized by GC/MS technique. Moreover, the impact of the sub-lethal concentrations of R. sativus roots extracts on transaminases and alkaline phosphatase of A. gossypii was studied. Great inhibition of all tested enzymes activity was observed. This suggested the high potency of R. sativus roots extracts as environmentally friendly alternatives of traditional insecticides.

Four isolates of Botryococcus braunii Kutzing were isolated from the Nile River in Egypt. The morphological examinations and results of 5.8S rRNA gene sequences confirmed that EG-Bb01 (JN580448.1), EG-Bb02 (JN580449.1), EG-Bb03 (JN580450.1) and EG-Bb04 (JN580451.1) are B. braunii. The isolates were cultivated in modified Chu 13 medium and incubated for 8 weeks at 25±1 °C under light intensity of 16 ± 3 μmol m−2 s−1 with 16:8 h light: dark cycle. The dry weight biomass ranged between 0.382 gl−1 and 0.628 gl−1 for the isolates EG-Bb03 and EG-Bb01. Also, the hydrocarbon production (% w/w) varied significantly (P ≤ 0.05) between 33% (EG-Bb03) and 53% (EG-Bb01). GC/MS analysis revealed marked qualitative and quantitative variations in hydrocarbon profile of B. braunii isolates. A total of 24 C16 C31 different compounds were identified. The hydrocarbon of the four isolates was mainly composed of aliphatic hydrocarbons with the odd carbon numbered C25 C31, indicating that these isolates are a typical race A of B. braunii. Isolate EG-Bb01 maintained the highest content of C25 C31 hydrocarbons of (36.44%). The hexahydrofarnesylacetone (C18H38O) ketone was detected in the four isolates with different proportions ranged between 0.216% (EG-Bb01) and 13.86% (EG-Bb04). Meanwhile, the alcohol hexacosanol C26H54O (31.52%) was only detected in the isolate EG-Bb03.

Myrtus nivellei is a plant traditionally used to treat diseases including infection of microbial origin. Several M. nivellei Batt. & Trab. extracts (dichloromethane, methanol and ethanol/water) were screened for their activity against 36 microorganisms, including strains resistant to antibiotics. These extracts inhibited on average 15 bacteria strains with minimum inhibition concentrations (MICs) ranging from 0.07 to 1.20 mg/mL. Bioassay guided fractionation was carried out with bioautography on TLC plates using four pathogenic bacteria strains, and following chromatographies (CPC and HPLC) led to the isolation of two novel enol ether nor-cadinane sesquiterpenes from the dichloromethane extract. The major compound (1) showed a strong antibacterial activity. Minimal inhibition concentration and minimal bactericidal concentration (MBC) values were determined against four bacteria: Acinetobacter baumanii, Stenotrophomonas maltophilia, Yersinia pseudotuberculosis and Staphylococcus lugdunensis. The best activity was observed against Acinetobacter baumanii with a MIC value of 9.7 μg/mL. This novel compound was also very active against a Staphylococcus aureus strain resistant to amoxicillin (MIC 19.5 μg/mL). In addition, compound 1 showed a very high antioxidant activity with both DPPH and metal chelate methods.

Chemical investigation of the whole Fagonia schimperi C. Presl plant yielded a new triterpene saponin, namely 3-O-β- xylopyranosyl-(1→2)-α-L-arabinopyranosyl-27-hydroxyoleanolic acid 28-O-β-glucopyranoside (1), along with five known natural products 2–6. Structures of the isolated compounds were elucidated by intensive spectroscopic methods including Electrospray Ionisation-Mass Spectrometry (ESI-MS) and 1D and 2D-NMR, which matched the literature data. Fagonia schimperi crude saponin fraction, ethyl acetate (EtOAc) fraction, and the new compound (1) were investigated for their biological activities as antibacterial, antioxidant, and cytotoxicity. EtOAc fraction and compound (1) were the most potent agents, wherein they displayed potent antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Additionally, the EtOAc fraction displayed potent antiproliferative activity against hepatocellular carcinoma and mammary gland with IC50 values of 7.38 ± 0.4 and 4.89 ± 0.3 μg/ml, respectively. Furthermore, compound 1 showed a significant cytotoxic activity against the two cell lines with IC50 values of 19.20 ± 1.4 and 8.18 ± 0.9, μg/ml, respectively. This comes in agreement with the antioxidant activity that was assessed by 2,2,1-diphenyl-1-picrylhydrazyl and SOD-like activity methods in the following order: EtOAc fraction > compound 1 > crude saponin fraction.

During the screening programme for antibiotic produced by actinomycetes, an antibiotic was isolated from the fermentation broth of Streptomyces anulatus NEAE-94. The ethyl acetate extract of S. anulatus NEAE-94 showed high biological activity against Staphylococcus aureus NRRL B-313, multidrug-resistant S. aureus and Bacillus subtilis NRRL B-543. Thin-layer chromatography of the ethyl acetate extract showed one yellowish orange spot with an Rf value of 0.83. The structural elucidation of the isolated compounds was carried out using ultraviolet–visible mass spectrometry (MS), Fourier transform-infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H-NMR) and gas chromatography–mass spectrometry (GC–MS) analyses. Characterization of the ethyl acetate extract revealed the presence of 22 compounds, including an unsaturated fatty acid, saturated fatty acids, fatty acid esters, alkanes, alkenes and a triterpene. The antimicrobial efficacy of S. anulatus NEAE-94 might be due to the synergistic effects of the identified compounds.

Marine natural products (MNPs) continue to be in the spotlight in the global drug discovery endeavor. Currently, more than 30,000 structurally diverse secondary metabolites from marine sources have been isolated, making MNPs a profound, renewable source to investigate novel drug compounds. Marine sponges of the genus Suberea (family: Aplysinellidae) are recognized as producers of bromotyrosine derivatives, which are considered distinct chemotaxonomic markers for the marine sponges belonging to the order Verongida. This class of compounds exhibits structural diversity, ranging from simple monomeric molecules to more complex molecular scaffolds, displaying a myriad of biological and pharmacological potentialities. In this review, a comprehensive literature survey covering the period of 1998⁻2018, focusing on the chemistry and biological/pharmacological activities of marine natural products from marine sponges of the genus Suberea, with special attention to the biogenesis of the different skeletons of halogenated compounds, is presented.

Pyrroloquinoline and guanidine-derived alkaloids present distinct groups of marine secondary metabolites with structural diversity that displayed potentialities in biological research. A considerable number of these molecular architectures had been recorded from marine sponges belonging to different marine genera, including Batzella, Crambe, Monanchora, Clathria, Ptilocaulis and New Caledonian starfishes Fromia monilis and Celerina heffernani. In this review, we aim to comprehensively cover the chemodiversity and the bioactivities landmarks centered around the chemical constituents exclusively isolated from these three marine genera including Batzella, Crambe and Monanchora over the period 1981–2017, paying a special attention to the polycyclic guanidinic compounds and their proposed biomimetic landmarks. It is concluded that these marine sponge genera represent a rich source of novel compounds with potential applications for cancer and other therapeutic areas.

Four previously undescribed sucrose diester of aryldihydronaphthalene-type lignans, named echiumins A-D, were isolated from the butanol fraction of Echium angustifolium Mill, in addition to a known compound, trigonotin A, which is reported for the first time from the title plant. The structures of isolated compounds were elucidated using spectroscopic methods such as HRESIMS and 1D and 2D NMR spectroscopy. The isolated compounds displayed strong to weak antitumor activity against HepG2 and MCF7 cancer cell lines, with echiumins A and D showed the most potent activity.