Two new aromatic constitutents from the rootwood of Aeschynomene mimosifolia

Medicinal Uses of the Fabaceae Family in Zimbabwe: A Review

The current study is aimed at providing a systematic review of the ethnomedicinal, phytochemical and pharmacological properties of Fabaceae species used as sources of traditional medicinies in Zimbabwe. Fabaceae is one of the well-known plant families of ethnopharmacological importance. Of the approximately 665 species of the Fabaceae family occurring in Zimbabwe, about 101 are used for medicinal purposes. Many communities in the country, mainly in peri-urban, rural and marginalized areas with limited access to healthcare facilities, rely on traditional medicines as their primary healthcare. The study reviewed research studies undertaken on Zimbabwe's Fabaceae species during 1959 to 2022. Information was gathered from literature sourced from Google Scholar, Science Direct, Scopus, PubMed, books, dissertations, theses and scientific reports. This study showed that 101 species are traditionally used to manage human and animal diseases in Zimbabwe. The genera with the highest number of medicinal uses are Indigofera, Senna, Albizia, Rhynchosia and Vachellia. Species of these genera are used as traditional medicines against 134 medical conditions, mainly gastrointestinal conditions, female reproductive conditions, respiratory conditions and sexually transmitted infections. Shrubs (39.0%), trees (37.0%) and herbs (18.0%) are the primary sources of traditional medicines, while roots (80.2%), leaves (36.6%), bark (27.7%) and fruits (8.9%) are the most widely used plant parts. Many of Zimbabwe's Fabaceae species used as sources of traditional medicines have been assessed for their phytochemical and pharmacological properties, corroborating their medicinal uses. However, there is a need to unravel the therapeutic potential of the family through further ethnopharmacological research focusing on toxicological studies, in vitro and in vivo models, biochemical assays and pharmacokinetic studies.

Leishmanicidal phenolic compounds derived from Dalbergia cultrata

Leishmaniasis is a protozoan tropical infection that is estimated to be more than 0.3 million new cases occur annually worldwide. A novel phenolic compound, cultratin A (1), was isolated as a leishmanicidal constituent from the timber of Dalbergia cultrata, along with three known neoflavanoids (2, 3, 4), two benzofurans (5, 6), and two phenolic compounds (7, 8). Their structures were determined using spectral methods. Among them, a new compound (1) and 4-(S)-methoxydalbergione (2) showed effective leishmanicidal activities (IC₅₀: 2.0 and 2.6 μM, respectively), while compound 8 showed moderate activity (IC₅₀: 11 μM). The cytotoxicity of compounds 1 and 2 was also weaker than that of the other compounds.

Applications of Friedel-Crafts reactions in total synthesis of natural products

Over the years, Friedel-Crafts (FC) reactions have been acknowledged as the most useful and powerful synthetic tools for the construction of a special kind of carbon-carbon bond involving an aromatic moiety. Its stoichiometric and, more recently, its catalytic procedures have extensively been studied. This reaction in recent years has frequently been used as a key step (steps) in the total synthesis of natural products and targeted complex bioactive molecules. In this review, we try to underscore the applications of intermolecular and intramolecular FC reactions in the total syntheses of natural products and complex molecules, exhibiting diverse biological properties.

Isolation and Identification of Cytotoxic Compounds from Aeschynomene fascicularis, a Mayan Medicinal Plant

The plant Aeschynomene fascicularis (Fabaceae) has been used in Mayan traditional medicine in the Yucatan peninsula. However, the compounds present in the plant responsible for its curative properties have not yet been investigated. Aeschynomene fascicularis root bark was extracted with 100% methanol to obtain a crude extract. The methanol extract was partitioned successively with solvents with increasing polarity to obtain the corresponding hexane (Hx), dichloromethane (DCM) and ethyl acetate fractions (EtOAc), as well as a residual water-alcoholic fraction. These fractions were tested for their cytotoxic activities using an MTT assay against Hep-2 cancer cell lines. The Hx fraction led to the isolation of spinochalcone C (1), spinochalcone A (2), isocordoin (3) and secundiflorol G (4). Their structures were identified based on spectroscopic evidence and chemical properties. All compounds were subjected to cytotoxicity and antiproliferative assays against a panel of seven cell lines, including one normal-type cell line. Spinochalcone A (2) exhibited cytotoxic activity against DU-145 cell line and antiproliferative activity against the KB cell line. Secundiflorol G (4) showed strong cytotoxic activity towards KB and Hep-2 cell lines. In addition, isocordoin (3) showed moderate activity on KB, Hep-2 and DU-145 cell lines. The active Compounds 2, 3 and 4 are potential therapeutic entities against cancer.

Screening of plants used in Mayan traditional medicine to treat cancer-like symptoms

AIM OF THE STUDY

To investigate the potential of plants used in Mayan traditional medicine to treat cancer-like symptoms using the Mayan ethnobotany literature, and evaluate their organic extracts for in vitro cytotoxic activity on cancer cell lines.

MATERIALS AND METHODS

The selection of the plants studied in this investigation was based on the Mayan ethnobotanical information provided by different literature sources. Extracts were obtained by maceration with methanol for 72 h of each plant part used and evaporated in vacuo to give the corresponding dried extract. Each methanol extract was tested for its cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay performed in 96-well tissue plates on seven cancer cell lines, lung carcinoma (A549), cervix adenocarcinoma (HeLa), laryngeal carcinoma (Hep-2), nasopharynx carcinoma (KB), breast adenocarcinoma (MCF-7), prostate adenocarcinoma (PC-3), and cervix squamous carcinoma cells (SiHa), as well as normal human embryonic kidney cell line (HEK-293). Cell proliferation/viability was spectrophotometrically assessed at 540 nm after addition of MTT.

RESULTS

51 plants were found in the literature to be used for the treatment of symptoms suggestive of cancer, 21 were chosen to evaluate the cytotoxic activity. Aeschynomene fascicularis root bark extract showed a pronounced cytotoxic activity on Hela and KB cell lines and Bonellia macrocarpa stem and root bark extracts showed similar prominent activities on KB cells.

CONCLUSION

21 plants were selected according to their use in the treatment of cancer-like symptoms recorded in the ethnobotanical literature. Plant extracts prepared from Aeschynomene fascicularis root bark and Bonellia macrocarpa stem and root bark have been selected for extensive studies leading to the isolation of the active constituents.

Relationships between inhibitory activity against a cancer cell line panel, profiles of plants collected, and compound classes isolated in an anticancer drug discovery project

In an attempt to determine the relationships between the plant profiles (country of collection, taxonomy, plant part) and the compound classes isolated with cytotoxic activity against a panel of human tumor cell lines, the data compiled from a 15-year anticancer drug-discovery project were subjected to an analysis of variance (ANOVA). The results indicate significant trends in cytotoxic activity relative to collection location, taxonomy, plant part, and compound classes isolated. Plant collections were made in tropical forests in six countries, with collections from Ecuador resulting in higher activity than those from Indonesia and Peru. Interestingly, collections from Florida were not statistically different than those from the countries with higher biodiversity. One hundred and forty-five families were represented in the collections, with the Clusiaceae, Elaeocarpaceae, Meliaceae, and Rubiaceae having low ED50 (half maximal effective dose) values. Especially active genera included Aglaia, Casearia, Exostema, Mallotus, and Trichosanthes. Roots and below-ground plant materials were significantly more active than above-ground materials. Cucurbitacins, flavaglines, anthraquinones, fatty acids, tropane alkaloids, lignans, and sesquiterpenoids were significantly more active than xanthones and oligorhamnosides. The results from this study should serve as a guide for future plant collection endeavors for anticancer drug discovery.

Alkaloids from Alangium javanicum and Alangium grisolleoides that mediate Cu2+-dependent DNA strand scission

Crude CH2Cl2-MeOH extracts prepared from Alangium javanicum and A. grisolleoides were found to induce DNA strand breakage in the presence of Cu2+ and were subjected to bioassay-guided fractionation to permit identification of the active principle(s). Javaniside (1), a novel alkaloid possessing an unusual monoterpenoid oxindole skeleton, was identified as an active principle contributing to the DNA cleavage activity observed for the crude extract of A. javanicum. Alangiside (2), a tetrahydroisoquinoline monoterpene glucoside widely distributed in the genus Alangium, was also isolated from A. grisolleoides as a new type of Cu2+-dependent DNA cleavage agent. The relative configuration of the asymmetric centers in javaniside was established by analysis of 1H-1H coupling constants and NOESY correlations. Semisynthesis of javaniside from secologanin (3) established the absolute stereochemistry of javaniside.

Enantioselective [4 + 2] cycloadditions of o-quinone methides: total synthesis of (+)-mimosifoliol and formal synthesis of (+)-tolterodine

The first example of an enantioselective cycloaddition of an o-quinone methide (o-QM) with a chiral enol ether is described along with the total synthesis of (+)-mimosifoliol and the formal synthesis of (+)-tolterodine. These syntheses exemplify a three-component, one-pot benzopyran approach for the construction of chiral benzylic junctions. Cycloadditions of various enol ethers and o-QMs are examined, and diastereoselectivities >95% are obtained with trans-2-phenyl-1-cyclohexanol and 2,2-diphenylcyclopentanol vinyl ethers.

A dihydroflavonol glucoside from Commiphora africana that mediates DNA strand scission

A crude CH(2)Cl(2)-MeOH extract prepared from Commiphora africana was found to mediate Cu(2+)-dependent relaxation of supercoiled plasmid DNA. Bioassay-guided fractionation of this extract was carried out and was monitored by the use of an in vitro DNA strand scission assay. The dihydroflavonol glucoside phellamurin (1) was identified as the active principle responsible for the DNA cleavage activity of the crude extract.

A coumarin from Mallotus resinosus that mediates DNA cleavage

A crude extract prepared from roots of Mallotus resinosus exhibited significant Cu(2+)-dependent DNA strand scission activity and was thus selected for bioassay-guided fractionation. Scopoletin (1), a simple coumarin, was identified as the active principle responsible for DNA cleavage activity of the crude extract. The DNA strand scission activity of 1, as well as that of three structural analogues, is reported.

Phenolic acid amides: a new type of DNA strand scission agent from Piper caninum

In a survey of the active components of crude plant extracts for their ability to cleave DNA, a crude extract prepared from Piper caninum was found to induce the relaxation of supercoiled pBR322 plasmid DNA in the presence of Cu(2+). Bioassay-guided fractionation was carried out on this extract, guided by an in vitro DNA strand scission assay. Three active principles were isolated and identified as N-cis-feruloyl tyramine (1),N-trans-feruloyl tyramine (2), and 1-cinnamoylpyrrolidine (3). Compounds 1-3 represent a structurally new type of DNA strand scission agent.

Rhenium-Catalyzed Aromatic Propargylation

A mild aromatic propargylation reaction, employing an air- and moisture-tolerant rhenium-oxo complex ((dppm)ReOCl(3)) as a catalyst and a propargyl alcohol as the electrophile, is described. The reaction tolerates a broad range of functional groups and regioselectively affords propargylic arenas without formation of the isomeric allenyl adducts. The potential of this rhenium(V)-catalyzed reaction is exemplified by application of the propargylation to the synthesis of O-methyldetrol, mimosifoliol, and beta-apopicropodophyllin. [reaction: see text]

Symmetric focal degeneration in the cerebellar and vestibular nuclei in swine caused by ingestion of Aeschynomene indica seeds

A vestibulocerebellar disorder was observed in 2- to 4-month-old swine after consumption of broken rice contaminated with 13% Aeschynomene indica seeds. Affected animals recovered in 2-14 days after removal of the contaminated food. To reproduce the syndrome, 10 pigs were fed 13% A. indica seeds in commercial pig ration or rice. They showed clinical signs similar to those observed in the spontaneous cases, 1 hour to 6 days after ingestion. Three pigs recovered after the withdrawal of the contaminated food. The others were killed. Two pigs that were fed for 25 days with food containing 3% and 6% seeds and two control pigs did not show clinical signs. Histologic lesions were characterized by symmetric focal degeneration in the cerebellar and vestibular nuclei. The initial lesion, observed 24 hours after the first ingestion, was characterized by vacuolation of the neuropil. Subsequently, there was progressive loss of parenchyma, vascular reaction, a few small spheroids, astrocytosis, and accumulation of gitter cells. The brains from four pigs were perfused with a buffered solution of glutaraldehyde-paraformaldehyde 12-48 hours after they started to ingest the seeds. No ultrastructural lesions were observed in the cerebellar nuclei after 12 hours of seed consumption. At 24 hours, endothelial cells and pericytes were separated by empty spaces from astrocyte foot processes, suggesting perivascular edema. The astrocytes were enlarged, consistent with intracellular fluid accumulation. These results suggest that A. indica seeds are toxic, causing functional derangement of the vestibulocerebellar system, followed by alterations in the microvasculature in the cerebellar and vestibular nuclei.