Combretum micranthum G. Don (Combretaceae): A Review on Traditional Uses, Phytochemistry, Pharmacology and Toxicology.

Combretum micranthum (Combretaceae) is a medicinal plant widely known and used in Africa to treat a variety of conditions such as diabetes, fever, coughs, bronchitis, diarrhea, pain, malaria and liver disorders, among others. Due to its wide traditional use, in this review, published scientific reports on its composition and pharmacological properties were explored by conducting a literature search of databases. To date, 155 organic compounds including 34 flavonoids, 16 phenolic acids, 14 alkaloids, 15 fatty acids, 14 terpenoids/steroids, 24 amino acids, 8 carbohydrate substances and 30 other organic compounds have been identified from this plant. In addition to these organic compounds, 6 minerals (potassium nitrate, calcium, magnesium, potassium, sodium, iron and zinc) have also been reported. In vitro and in vivo studies have shown that these phytochemicals and plant extracts have a wide range of pharmacological potential, including antibacterial, antiviral, antioxidant, antidiabetic, anti-inflammatory, analgesic, antihypertensive, nephroprotective, hepatoprotective, anxiolytic, anti-cholinesterase and antidiarrheal activities. Additionally, no harmful effects have been revealed through studies. Thus, this study could constitute a valuable reference for the valorization of C. micranthum in the pharmaceutical industry.

Cherimolacyclopeptide D, a novel cycloheptapeptide from the seeds of Annona cherimola.

In a chemical investigation of the seeds of Annona cherimola, a natural cyclic heptapeptide, cherimolacyclopeptide D, were isolated and purified by HPLC with three known cyclic peptides, cherimolacyclopeptides A, B and C. The structure was established by various analyses including MS/MS fragmentation, spectroscopic and chemical evidences.

Glaucacyclopeptide A from the seeds of Annona glauca.

The seeds of Annona glauca furnished two cyclopeptides one of which is novel. The structure was elucidated on the basis on mass spectrometry, 2D NMR methods and amino acids analysis.

Chemical communication between the endophytic fungus Paraconiothyrium variabile and the phytopathogen Fusarium oxysporum.

Paraconiothyrium variabile, one of the specific endophytic fungi isolated from the host plant Cephalotaxus harringtonia, possesses the faculty to inhibit the growth of common phytopathogens, thus suggesting a role in its host protection. A strong antagonism between the endophyte P. variabile and Fusarium oxysporum was observed and studied using optic and electronic microscopies. A disorganization of the mycelium of F. oxysporum was thus noticed. Interestingly, the biological effect of the main secondary metabolites isolated from P. variabile against F. oxysporum did not account for this strong antagonism. However, a metabolomic approach of pure fungal strains and confrontation zones using the data analysis tool XCMS were analyzed and pointed out a competition-induced metabolite production by the endophyte in the presence of the phytopathogen. Subsequent MS/MS fragmentations permitted to identify one of the induced metabolites as 13-oxo-9,11-octadecadienoic acid and highlighted a negative modulation of the biosynthesis of beauvericin, one of the most potent mycotoxin of F. oxysporum, during the competition with the endophyte.

A cytotoxic cyclic heptapeptide from the seeds of Annona cherimola.

From a methanol extract of the seeds of Annona cherimola, a new cyclic heptapeptide, cherimolacyclopeptide C, has been isolated. The structure was elucidated on the basis of the MS/MS fragmentation using a Q-TOF mass spectrometer equipped with an ESI source, extensive 2D NMR experiments, and chemical degradation. Cherimolacyclopeptide C exhibited significant in vitro cytotoxic activity against KB cells, with an IC(50) value of 0.072 microM.