Analytical Laboratory

Leptomonines A and B, two novel rare benzyltetrahydroisoquinoline N-oxides, were isolated from the aerial parts of Leptopyrum fumarioides (L.) Reichenb. collected in Tuv province, Mongolia. Their chemical structures, absolute configurations, and conformations were established by 2D-NMR and CD spectral analyses. Leptomonine A (1) can suppress TNF-α production and COX-2 expression in LPS-stimulated RAW 267.4 cells. This compound at a concentration of 100 μM significantly reduced the TNF-α and COX-2 levels by 36.43% and 47.10%, respectively, compared with the negative control. Moreover, leptomonine B (2) remarkably lowers COX-2 levels at the highest concentration. The docking simulations were conducted with the COX-2 enzyme and revealed the binding ability of leptomonine A (1) and leptomonine B (2) with binding energies of − 9.03 and − 8.96 kcal/mol, respectively. The interactions of these alkaloids with the targets were mainly with the hydrophobic and hydrophilic sites, which are quite similar to rofecoxib. Phytochemical investigation revealed the diversity and novelty of the natural isoquinoline alkaloids in Leptopyrum fumarioides. Two new benzyltetrahydroisoquinoline N-oxides were identified as the bioactive constituents of Leptopyrum fumarioides by assessing its anti-inflammatory effects. The findings provide scientific justification to support the traditional application of Leptopyrum fumarioides for treating liver diseases associated with inflammation.

Microbial biological control agents are increasingly used as an alternative to synthetic pesticides. The application of these microorganisms massively affects all members of plant‐colonising microbial communities, including pathogenic fungi. In the majority of cases, the resulting competition for ecological niches is decided by the toxicity of microbial secondary metabolites (SMs) formed. In this study, we devised confrontation experiments employing the fungal maize pathogen Colletotrichum graminicola and antagonistic partners, that is the biocontrol bacterium Bacillus amyloliquefaciens and the ubiquitous ascomycete Aspergillus nidulans. Transcriptome studies uncovered strong de‐regulation of the vast majority of the C. graminicola secondary metabolite biosynthetic gene clusters (SMBGCs), with 69% and 86% of these clusters de‐regulated at confrontation sites with B. amyloliquefaciens or A. nidulans, respectively. In the biocontrol bacterium and in A. nidulans confronting the maize pathogen, 100% and 74% of the SMBGCs were transcriptionally de‐regulated, respectively. Correspondingly, non‐targeted high‐resolution LC–MS/MS revealed a large repertoire of 1738 and 1466 novel features formed in the fungus–bacterium and fungus–fungus confrontation, respectively. Surprisingly, several of these belong to chemical classes with lead structures of synthetic fungicides.

Three novel complexes of deprotonated diflunisal (dif) with neocuproine (neo) were synthesized and characterized via elemental, spectral (UV-vis, FTIR, fluorescence, and mass spectrometry), and single-crystal X-ray diffraction analyses. Although the compounds shared a similar composition of [MCl(dif)(neo)], where M represents Zn(II) (1), Co(II) (2) and Cu(II) (3), only 1 and 2 were isostructural, while 3 differed in both the molecular and supramolecular structures. In all three complex molecules, the central atom is coordinated by two nitrogen atoms of neo in a bidentate chelate mode, and one chlorido ligand and dif is bonded in either a monodentate mode via one oxygen atom of the carboxylate in 1 and 2 or in a bidentate chelate mode via both carboxylate oxygen atoms in 3. All three compounds demonstrated remarkable antiproliferative activity against human prostate (PC-3), colon (HCT116) and breast (MDA-MB-468) cancer cell lines with IC50 values in the nanomolar range, with the lowest values observed in the case of PC-3 and MDA-MB-468 with 2 (20.0 nM) and 3 (31.1 nM), respectively. Moreover, complex 2, as the most active, was further investigated for its potential to induce perturbations in the cell cycle of PC-3 cells. The results indicated an induction of caspase-independent apoptosis. The interaction of the complexes with genomic DNA isolated from the respective cancer cell lines was evaluated for the intercalative mode, with binding strength correlated with the antiproliferative activity against PC-3 and MDA-MB-468 cancer cell lines.

Indole-3-carbinol (I3C) is a major dietary component produced in Brassica vegetables from glucosinolates (GLS) upon herbivores’ attack. The compound is gaining increasing interest due to its anticancer activity. However, reports about improving its level in plants or other sources are still rare. Unfortunately, I3C is unstable in acidic media and tends to polymerize rendering its extraction and detection challenging. This review presents a multifaceted overview of I3C regarding its natural occurrence, biosynthesis, isolation, and extraction procedure from dietary sources, and optimization for the best recovery yield. Further, an overview is presented on its metabolism and biotransformation inside the body to account for its health benefits and factors to ensure the best metabolic yield. Compile of the different analytical approaches for I3C analysis in dietary sources is presented for the first time, together with approaches for its detection and its metabolism in body fluids for proof of efficacy. Lastly, the chemopreventive effects of I3C and the underlying action mechanisms are summarized. Optimizing the yield and methods for the detection of I3C will assist for its incorporation as a nutraceutical or adjuvant in cancer treatment programs. Highlighting the complete biosynthetic pathway and factors involved in I3C production will aid for its future biotechnological production.

The new species Cortinarius steglichii is described from Chilean Nothofagus forest based on morphological and microscopical attributes, molecular phylogeny, and chemical analysis of secondary metabolites. C. steglichii is characterized by abundant, long, ramified cystidia on the lamellar edges and stipe apex, further by a deep violet color reaction after treatment with KOH. As responsible secondary metabolite for the cytoplasmatic color reaction of cystidia and some hyphae, the new diterpenoid steglichon (1) could be recognized, showing also remarkable antibacterial and anticancer activity. Phylogenetic analyses (ITS, LSU, RPB1) confirm the close relationship to species of the Cortinarius dulciolens group.

Ru(II)‐arene compounds are being investigated as anticancer agents due to the biocompatibility of ruthenium and their structural diversity. Two newly synthesized Ru(II) complexes, [RuCl(η6‐p‐cymene)(3‐DNPH)] (chlorido(η6‐p‐cymene)(3‐nitrophenylhydrazine‐k2N,N′)ruthenium(II)) (1) and [RuCl(η6‐p‐cymene)(3‐CNPH)] (chlorido(3‐chlorophenylhydrazine‐k2N,N′)(η6‐p‐cymene)ruthenium(II)) (2), are experimentally (IR, NMR) and theoretically (B3LYP/6‐31+G(d,p)(H,C,N,Cl)/LanL2DZ(Ru)) characterized. Experimental and theoretical values of 1H and 13C chemical shifts and position of the most intense vibrational bands showed high correlation coefficients and low mean absolute errors, proving the predicted structure and applicability of the selected level of theory. Cell viability studies performed on MDA‐MB‐468, BT‐474, and PC3 cells using MTT and CV assay indicated the activity of the second complex similar to the activity of cisplatin towards BT‐474 breast cancer cells. The spectrofluorimetric measurements of Bovine Serum Albumin showed the binding process‘s spontaneity of complexes and protein, with a binding energy of around −30 kJ mol−1. Detailed molecular docking analysis allowed the elucidation of the binding mechanism through specific intermolecular interactions. Both compounds showed a higher affinity towards BSA than naproxen and cisplatin. Molecular docking simulations proved the spontaneity of the complexes binding to DNA. Based on these promising results, further biological examinations of these compounds are advised.Graphical Abstract The cytotoxicity, protein binding affinity, interactions with DNA, spectral and structural features of two new Ru(II) compounds, [RuCl(η6-p-cymene)(3-DNPH)] chlorido(η6-p-cymene)(3-nitrophenylhydrazine-k2N,N′)ruthenium(II) and [RuCl(η6-p-cymene)(3-CNPH)] chlorido(3-chlorophenylhydrazine-k2N,N′)(η6-p-cymene)ruthenium(II), are examined experimentally and theoretically.

Organotin(IV) carboxylates are a class of compounds explored as alternatives to platinum-containing chemotherapeutics due to propitious in vitro and in vivo results, and distinct mechanisms of action. In this study, triphenyltin(IV) derivatives of non-steroidal anti-inflammatory drugs (indomethacin (HIND) and flurbiprofen (HFBP)) are synthesized and characterized, namely [Ph3Sn(IND)] and [Ph3Sn(FBP)]. The crystal structure of [Ph3Sn(IND)] reveals penta-coordination of the central tin atom with almost perfect trigonal bipyramidal geometry with phenyl groups in the equatorial positions and two axially located oxygen atoms belonging to two distinct carboxylato (IND) ligands leading to formation of a coordination polymer with bridging carboxylato ligands. Employing MTT and CV probes, the antiproliferative effects of both organotin(IV) complexes, indomethacin, and flurbiprofen were evaluated on different breast carcinoma cells (BT-474, MDA-MB-468, MCF-7 and HCC1937). [Ph3Sn(IND)] and [Ph3Sn(FBP)], unlike the inactive ligand precursors, were found extremely active towards all examined cell lines, demonstrating IC50 concentrations in the range of 0.076–0.200 µM. Flow cytometry was employed to examine the mode of action showing that neither apoptotic nor autophagic mechanisms were triggered within the first 48 h of treatment. However, both tin(IV) complexes inhibited cell proliferation potentially related to the dramatic reduction in NO production, resulting from downregulation of nitric oxide synthase (iNOS) enzyme expression.

Balanites aegyptiaca (L.) Delile (Zygophyllaceae), also known as the desert date, is an edible fruit-producing tree popular for its nutritional and several health benefits. In this study, multi-targeted comparative metabolic profiling and fingerprinting approaches were conducted for the assessment of the nutrient primary and secondary metabolite heterogeneity in different parts, such as leaves, stems, seeds, unripe, and ripe fruits of B. aegyptiaca using nuclear magnetic resonance (NMR), ultra-performance liquid chromatography (UPLC-MS), and gas chromatography mass-spectrometry (GC-MS) based metabolomics coupled to multivariate analyses and in relation to its cytotoxic activities. NMR-based metabolomic study identified and quantified 15 major primary and secondary metabolites belonging to alkaloids, saponins, flavonoids, sugars, and amino and fatty acids. Principal component analysis (PCA) of the NMR dataset revealed α-glucose, sucrose, and isorhamnetin as markers for fruit and stem and unsaturated fatty acids for predominated seeds. Orthogonal projections to latent structure discriminant analysis (OPLS-DA) revealed trigonelline as a major distinctive metabolite in the immature fruit and isorhamnetin as a major distinct marker in the mature fruit. UPLC-MS/MS analysis using feature-based molecular networks revealed diverse chemical classes viz. steroidal saponins, N-containing metabolites, phenolics, fatty acids, and lipids as the constitutive metabolome in Balanites. Gas chromatography-mass spectroscopy (GC-MS) profiling of primary metabolites led to the detection of 135 peaks belonging to sugars, fatty acids/esters, amino acids, nitrogenous, and organic acids. Monosaccharides were detected at much higher levels in ripe fruit and disaccharides in predominate unripe fruits, whereas B. aegyptiaca vegetative parts (leaves and stem) were rich in amino acids and fatty acids. The antidiabetic compounds, viz, nicotinic acid, and trigonelline, were detected in all parts especially unripe fruit in addition to the sugar alcohol D-pinitol for the first time providing novel evidence for B. aegyptiaca use in diabetes. In vitro cytotoxic activity revealed the potential efficacy of immature fruit and seeds as cytotoxic agents against human prostate cancer (PC3) and human colorectal cancer (HCT-116) cell lines. Collectively, such detailed profiling of parts provides novel evidence for B. aegyptiaca medicinal uses.