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Bocconia arborea S. Watson (Papaveraceae) is an abundant medicinal plant in the North of Morelos State, Mexico, which is used for the treatment of several diseases. The aim of current investigation was to isolate the compounds responsible of the relaxant effect shown by the active extracts. Thus, phytochemical bio-guided fractionation allowed the isolation of angoline (1), dihydrosanguinarine (2), bocconarborine A (3), oxisanguinarine (4), and oxychelerithrine (5) from dichloromethanic and methanolic extracts from the bark of Bocconia arborea (Papaveraceae). The relaxant study on aortic and tracheal rat rings of all benzophenanthridines indicates that 1 was the most active compound of the entire series investigated. Angoline (1) induces its relaxant effect by a concentration-dependent manner through the calcium channel blockade in both tissues., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The Libellus de Medicinalibus Indorum Herbis (Booklet of Indian Medicinal Plants) is the first book of medicinal plants written in the American continent. It was first published in 1939 as 'An Aztec Herbal'. One of the depicted plants is Huetzcanixochitl (laughing flower) interpreted as Zephyranthes fosteri (Amaryllidaceae). No chemical or pharmacological studies are reported for this species; so, we decide to investigate it. The GC/MS of the bulbs and aerial parts extracts indicated that they contain Amaryllidaceae alkaloids, among them: lycorine, 3-O-acetylpowelline, and norlycoramine. An unknown major alkaloid was isolated and identified by 1 H, 13 C-NMR and MS, as 3'-demethoxy-6-epimesembranol (1). The methanolic extract, the alkaloid fraction, and compound 1 inhibited acetylcholinesterase in vitro. Mesembrine alkaloids are found in Sceletium species (Aizoaceae). Several are known as serotonin recapture inhibitors and have been proposed as potential antidepressant drugs. The presence of 1 suggests that Z. fosteri was probably used in pre-Columbian times in Mexico as a 'stimulant and euphoriant', alike Sceletium tortuosum by several ethnic groups in South Africa., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

Because most species are collections of genetically variable populations distributed to habitats differing in their abiotic/biotic environmental factors and community composition, the pattern and strength of natural selection imposed by species on each other's traits are also expected to be highly spatially variable. Here, we used genomic and quantitative genetic approaches to understand how spatially variable selection operates on the genetic basis of plant defenses to herbivores. To this end, an F 2 progeny was generated by crossing Datura stramonium (Solanaceae) parents from two populations differing in their level of chemical defense. This F 2 progeny was reciprocally transplanted into the parental plants' habitats and by measuring the identity by descent (IBD) relationship of each F 2 plant to each parent, we were able to elucidate how spatially variable selection imposed by herbivores operated on the genetic background (IBD) of resistance to herbivory, promoting local adaptation. The results highlight that plants possessing the highest total alkaloid concentrations (sum of all alkaloid classes) were not the most well-defended or fit. Instead, specific alkaloids and their linked loci/alleles were favored by selection imposed by different herbivores. This has led to population differentiation in plant defenses and thus, to local adaptation driven by plant-herbivore interactions., (© 2020 The Authors. Evolution © 2020 The Society for the Study of Evolution.)

The pyrrole-imidazoles, a group of alkaloids commonly found in marine sponges belonging to the genus Agelas , display a wide range of biological activities. Herein, we report the first chemical study of the secondary metabolites of the sponge A. dilatata from the coastal area of the Yucatan Peninsula (Mexico). In this study, we isolated eight known alkaloids from an organic extract of the sponge. We used NMR and MS analysis and comparison with existing databases to characterize the alkaloids: ageliferin ( 1 ), bromoageliferin ( 2 ), dibromoageliferin ( 3 ), sceptrin ( 4 ), nakamuric acid ( 5 ), 4-bromo-1H-pyrrole-2-carboxylic acid ( 6 ), 4,5-dibromopyrrole-2-carboxylic acid ( 7 ) and 3,7-dimethylisoguanine ( 8 ). We also evaluated, for the first time, the activity of these alkaloids against the most problematic multidrug-resistant (MDR) pathogens, i.e., the Gram-negative bacteria Pseudomonas aeruginosa , Klebsiella pneumoniae and Acinetobacter baumannii . Bromoageliferin ( 2 ) displayed significant activity against P. aeruginosa . Comparison of the antibacterial activity of ageliferins 1 - 3 (of similar structure) against P. aeruginosa revealed some relationship between structure and activity. Furthermore, in in vitro assays, 2 inhibited growth and biofilm production in clinical strains of P. aeruginosa . Moreover, 2 increased the survival time in an in vivo Galleria mellonella model of infection. The findings confirm bromoageliferin ( 2 ) as a potential lead for designing new antibacterial drugs.

The chemical composition of the essential oil and the n-hexane (Hex), Ethyl Acetate (EtOAc) and butanol (BuOH) extracts from the leaves of Helietta parvifolia were determined by detailed GC-MS analysis, spectroscopic and spectrometric data. Eighty-four compounds were identified, revealing a furoquinoline alkaloid-rich composition. The phytochemical analysis of the extracts allowed the isolation of eigth furoquinoline alkaloids. Retention indices in GC-MS for six of this alkaloids are reported for the first time. Furoquinoline alkaloids are acethylcholinesterase inhibitors. Thus, the essential oil and extracts were submitted to this in vitro assay. The EtOAc and BuOH extracts showed potent activity, with IC 50 of 9.7 and 12.9 μg mL -1 , respectively. Additionaly, a correlation of their chemical constituents, established by principal component analysis (PCA) demostrated a similar profile and a high content of alkaloids. It is for these reasons that we can assume that the alkaloid content in these extracts could be responsible for their anticholinesterase activity.

Annona purpurea grows in the areas of low elevation in deciduous forests of Mexico, those areas have marked rainy and dry seasons. This species produces more than 30 bioactive alkaloids that could have potential in the control of phytopathogens. This research provides data on the variation of the content and number of alkaloids during an annual cycle and the associated inhibitory potential of the compounds against three phytopathogenic fungi. For one year, alkaloidal extracts of stems and leaves were obtained every two months. The extract profiles were determined by gas chromatography with tandem mass spectrometry and their antifungal activity was examined in vitro. The alkaloids, annomontine and oxopurpureine, obtained from the roots and leaves, respectively, were also evaluated individually. The yields, profiles and activities of the extracts, as well as the abundance of annomontine and oxopurpureine in the extracts, were contrasted with the seasonality and phenological phases of the plant. The data indicate that the alkaloid content was higher at the height of the dry season. High yields also occurred during flowering. The strongest inhibitory effect was obtained from the root extracts during the last month of dry season. This finding seems to be explained by the higher chemodiversity of alkaloids in extracts from this season. Annomontine and oxopurpureine inhibited all three phytopathogens; however, they were not solely responsible for the activity of A. purpurea., (© 2019 Wiley-VHCA AG, Zurich, Switzerland.)

Ethnopharmacological Relevance: Several species of Annona (Annonaceae) are used in traditional Mexican medicine by their anti-anxiety, anticonvulsant and tranquilizing properties. It has been reported that the alkaloids isolated from some species of the Annona have affinity to serotonergic 5-HT(1A) receptors and modulate dopaminergic transmission, which is involved in depressive disorders., Aim of the Study: To investigate the antidepressant-like effect of an alkaloid extract from the aerial parts of Annona cherimola (TA) in mice., Materials and Methods: The antidepressant-like effect was evaluated in the forced swimming test. To elucidate a possible mechanism of action, experiments of synergism with antidepressant drugs, such as imipramine (IMI), clomipramine (CLIMI), and fluoxetine (FLX), were carried out. The neurotransmitter content (DA: dopamine, 5HT: serotonin and its metabolites, HVA: homovanillic acid and 5HIAA: 5-hydroxyindoleacetic) in the whole brain of mice were also determined by HPLC method. TA chemical composition was determined using high performance liquid chromatography-electrospray mass spectrometry., Results: The results showed that repeated treatment with TA produced antidepressant-like effects in mice. This effect was not related to an increase in locomotor activity. Administration of TA facilitated the antidepressant effect of IMI and CLIMI as well as increased the turnover of DA and 5-HT. The alkaloids: 1,2-dimethoxy-5,6,6a,7-tetrahydro-4H-dibenzoquinoline-3,8,9,10-tetraol, anonaine, liriodenine, and nornuciferine were the main constituents of TA., Conclusions: Results showed that TA produces an antidepressant-like action from a generalized increase in monominergic turnover, supporting the use in tradicional medicine of Annona cherimolia, and strongly suggest its therapeutic potency as an antidepressant agent., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Hamelia patens JAQC. (Rubiaceae) is a medicinal bush widely distributed in tropical areas of the American continent. It is used in Mexican Traditional Medicine for the treatment of menstrual disorders, therefore suggesting that its chemical constituents may have some effect on myometrium contractility. Physiological effects might differ due to quantitative variations in the content of alkaloids arising from its wide geographical distribution. To test this hypothesis, the content of oxindole alkaloids in methanol extracts of five different samples collected in Mexico was quantified by GC-MS. Each extract was assayed on contractility of estrogen-primed rat myometrium. Variations in the content of alkaloids were observed among the different samples. All samples relaxed in a concentration-dependent manner the high KCl-induced contraction in rat myometrium. Those which lack rumberine and/or maruquine displayed a higher relaxant effect than samples containing them, suggesting that these alkaloids might counteract the effects of isopteropodine. However, in contrast with verapamil, Hamelia patens metanol extracts are poor relaxants.

Tecostanine (1) was isolated from Tecoma stans leaves. Its sterochemistry was elucidated as well as its antihyperglycemic activity and its affinity to opioid and nicotinic receptors. The oxalate salt of 1 did not significantly affect blood glucose levels in normoglycaemic and hyperglycaemic rats. It did not appear to interact with opioid receptors (mu type) and showed only moderate affinity to the nicotinic receptor.

Two alkaloid constituents of Bocconia arborea showed considerable antimicrobial activity against gram-positive and gram-negative bacteria and Candida albicans. Bioactivity-guided fractionation with thin-layer bioautography led to the isolation of the two known benzophenanthridine alkaloids, dihydrochelerythrine and dihydrosanguinarine. The minimal inhibitory concentration was determined for each compound using a twofold serial dilution assay. The structures of these compounds were determined by 1H and 13C NMR analyses.

Three sesquiterpene evoninoate alkaloids, hippocrateine I [1], hippocrateine II [2], and emarginatine A have been isolated from the root and stem barks of Hippocratea excelsa. Compounds 1 and 2 are new naturally occurring substances. The structure of 1 was unequivocally established by X-ray crystallographic analysis, and the structure of the second new alkaloid was deduced by spectral analysis.