Monitoring transformation of two tropical lignocellulosics and their lignins after residence in Benin soils.

Thermally assisted Hydrolysis and Methylation (THM), and 2D-heteronuclear single quantum coherence nuclear magnetic resonance (2D HSQC NMR) spectroscopy were used to monitor the transformation of ramial chipped wood (RCW) from Gmelina arborea and Sarcocephalus latifolius, together with their organosolv lignins, following soil incubation in Benin (West Africa). Mesh litterbags containing RCW were buried in soils (10 cm depth) and were retrieved after 0, 6, 12 and 18 months of field incubation. Chemical analysis showed that total carbohydrate content decreased, while total lignin content increased as RCW decomposition progressed.

Further isolation and identification of anti-diabetic principles from root bark of Myrianthus arboreus P. Beauv.: The ethyl acetate fraction contains bioactive phenolic compounds that improve liver cell glucose homeostasis.

Ethnopharmacological Relevance: We recently reported that ethanol extract of Myrianthus arboreus P. Beauv. root bark demonstrated antidiabetic activity by modulating hepatocyte glucose homeostasis.

Bioactive Pentacyclic Triterpenes from the Root Bark Extract of Myrianthus arboreus, a Species Used Traditionally to Treat Type-2 Diabetes.

Four new Δ ursene-type pentacyclic triterpenes containing the trans-feruloyl moiety (1-4), along with ursolic acid (5), were isolated from a Myrianthus arboreus root bark ethanol extract, after bioassay-guided subfractionation of its hexane fraction. The structures of 1-4 were established on the basis of the results of standard spectroscopic analytical methods (IR, HRESIMS, GC-MS, 1D and 2D NMR). The compounds 3β- O- trans-feruloyl-2α,19α-dihydroxyurs-12-en-28-oic acid (1), 2α-acetoxy-3β- O- trans-feruloyl-19α-hydroxyurs-12-en-28-oic acid (3), and 5 were determined to decrease the activity of hepatocellular glucose-6-phosphatase (G6Pase) and to activate glycogen synthase (GS).

Root bark extracts of Myrianthus arboreus P. Beauv. (Cecropiaceae) exhibit anti-diabetic potential by modulating hepatocyte glucose homeostasis.

Ethnopharmacological Relevance: Myrianthus arboreus P. Beauv. is a tropical tree used in African folk medicine, including for diabetes.

Study of Polyphenol Content and Antioxidant Capacity of Myrianthus Arboreus (Cecropiaceae) Root Bark Extracts.

In order to evaluate the therapeutic potential of polyphenolic extracts from root bark of M. arboreus, we have determined the content of various polyphenols in aqueous and ethanol (EtOH) extract as well as two sub-fractions of the latter: ethyl acetate (EAc) and hexane (Hex). The total phenols, flavonoids, hydroxycinnamic acids and proanthocyanidins have been determined for all studied extracts/fractions by spectrophotometric methods.