ABSTRACT
Tylosema esculentum (morama) is a highly valued traditional food and source of medicine for the San and other indigenous populations that inhabit the arid to semi-arid parts of Southern Africa. Morama beans are a rich source of phenolic acids, flavonoids, certain fatty acids, non-essential amino acids, certain phytosterols, tannins and minerals. The plant's tuber contains griffonilide, behenic acid and starch. Concoctions of extracts from morama bean, tuber and other local plants are frequently used to treat diarrhoea and digestive disorders by the San and other indigenous populations. Information on composition and bioactivity of phytochemical components of T. esculentum suggests that the polyphenol-rich extracts of the bean testae and cotyledons have great potential as sources of chemicals that inhibit infectious microorganisms (viral, bacterial and fungal, including drug-resistant strains), offer protection against certain non-communicable diseases and promote wound healing and gut health. The potential antinutritional properties of a few morama components are also highlighted. More research is necessary to reveal the full prophylactic and therapeutic potential of the plant against diseases of the current century. Research on domestication and conservation of the plant offers new hope for sustainable utilisation of the plant.
Subject(s)
Fabaceae , Plant Extracts , Africa, Southern , Fabaceae/chemistry , Flavonoids , Plant Extracts/pharmacology , Polyphenols , Tannins/pharmacologyABSTRACT
A series of 3-nitrochalcones have been synthesized enroute towards fused ring pyrazolones and isoxazolones. Base catalyzed condensation of the chalcones with ethylacetoacetate yielded cyclohexenones in good yields (74-76%). The treatment of cyclohexenones with hydrazine hydrate or hydroxylamine chloride in the presence of a base afforded the corresponding fused-ring pyrazolinones (70-78% yield) and isoxazolinones (58-66% yield). The newly synthesized compounds were characterized by IR, 1D and 2D NMR and HRMS spectral analysis. The compounds were screened for their antioxidant and antimicrobial activities. Pyrazolinones showed good DPPH radical scavenging and iron metal chelating properties. The para-hydroxy group was important for a compound to have enhanced antioxidant activity. Pyrazolinones and isoxazolinone exhibited a wider range of antimicrobial activities compared to cyclohexenones. Pyrazolinones and isoxazolinone bearing a thiophene ring were the most potent type of compounds against Bacillus subtilis and Candida albicans with MIC values of 0.313-1.25 µg/mL. Some of the synthesized compounds were found to have promising antioxidant, metal chelation and antimicrobial activities.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Antioxidants/pharmacology , Bacillus subtilis/drug effects , Candida albicans/drug effects , Isoxazoles/pharmacology , Pyrazolones/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antioxidants/chemical synthesis , Antioxidants/chemistry , Dose-Response Relationship, Drug , Isoxazoles/chemical synthesis , Isoxazoles/chemistry , Microbial Sensitivity Tests , Molecular Structure , Pyrazolones/chemical synthesis , Pyrazolones/chemistry , Structure-Activity RelationshipABSTRACT
In this study, 12 compounds, which include a new flavanone 5-methoxy mundulin, were isolated from the leaves, stem bark and twigs of Mundulea sericea (Willd.) A. Chev. (Fabaceae; Papilionoideae). The structures of the compounds were identified based on spectral data analyses. The constituents of M. sericea also showed antimicrobial activities (MIQ = 0.01-100 µg) against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Fabaceae/chemistry , Bacillus subtilis/drug effects , Candida albicans/drug effects , Drug Evaluation, Preclinical , Escherichia coli/drug effects , Flavonoids/chemistry , Microbial Sensitivity Tests , Molecular Structure , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Leaves/chemistry , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effectsABSTRACT
The investigation of Tylosema esculentum (Morama) husks, cotyledons, and tuber yielded griffonilide 2, compound 1, griffonin 3, gallic acid 4, protocatechuic acid 5, ß-sitosterol 6, behenic acid 7, oleic acid 8, sucrose 9, 2-O-ethyl-α-D-glucopyranoside 10, kaempferol 11 and kaempferol-3-O-ß-D-glucopyranoside 12. The structures of the isolates were determined by NMR, HR-TOF EIMS, IR and UV-vis spectroscopy, and by comparison with literature data. The husk EtOAc and n-butanol extracts demonstrated >90% DPPH radical scavenging activity at concentrations of 25, 50 and 250 µg/mL. Furthermore the husk extracts showed higher total phenolic content (233 mg GAE/g). The extractives exhibited minimum inhibitory quantities of 50-100 µg or no activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans. The tuber extracts were inactive against Caco-2 and Hela cell lines, while the husk extracts showed low activity against Caco-2 and Vero cell line with IC(50) values >400 µg/mL. The GC-MS analysis showed the beans and tuber non-polar (n-hexane) extracts major constituents as fatty acids.
