Synthesis and evaluation of 29-norcycloartane triterpenoids as α-glucosidase inhibitors

Research status of indole-modified natural products

Indole is a heterocyclic compound formed by the fusion of a benzene ring and pyrrole ring, which has rich biological activity. Many indole-containing compounds have been sold on the market due to their excellent pharmacological activity. For example, vincristine and reserpine have been widely used in clinical practice. The diverse structures and biological activities of natural products provide abundant resources for the development of new drugs. Therefore, this review classifies natural products by structure, and summarizes the research progress of indole-containing natural product derivatives, their biological activities, structure-activity relationship and research mechanism which has been studied in the past 13 years, so as to provide a basis for the development of new drug development.

Screening of Musa balbisiana Colla. seeds for antidiabetic properties and isolation of apiforol, a potential lead, with antidiabetic activity

BACKGROUND

'Phytonutrients' have been reported to exert an incredible impact on the healthcare system and offer medical benefits including the prevention or treatment of lifestyle-associated diseases. We chose one of the most common and important plant families, Musaceae, for our present study and explored its antidiabetic potential.

RESULTS

Seeds of the edible fruits of Musa balbisiana Colla. were investigated for their antidiabetic potential. After estimating the proximate composition, the seeds were extracted with various solvents and evaluated for antidiabetic potential in terms of the inhibition of digestive enzymes, antiglycation activity and in vitro glucose uptake. The acetone extract demonstrated the highest inhibition of α-amylase and α-glucosidase enzymes with IC₅₀ values of 36.67 ± 0.367 and 100.61 ± 0.707 µg mL^-1 , respectively. The extract also exhibited significant glycation inhibition with an IC₅₀ value of 86.48 ± 0.751 µg mL^-1 . Furthermore, a major phytochemical, apiforol, was isolated from the acetone extract for the first time, which demonstrated promising α-glucosidase inhibition (IC₅₀  = 48.25 ± 0.255 µmol L^-1 ), antiglycation property (IC₅₀  = 114.23 ± 0.567 µmol L^-1 ) and enhanced glucose uptake in L6 myoblasts. In molecular docking studies, apiforol efficiently bonded to the active sites of α-glucosidase enzyme 3A4A.

CONCLUSIONS

As dietary intervention is one of the effective strategies for addressing diabetes, special attention is always given to natural food bio-actives or agro-products for better human health. The results of our study suggest that Musa balbisiana has significant potential as an ingredient in health food formulations by reducing postprandial hyperglycaemia. © 2018 Society of Chemical Industry.

Inhibition of Alpha-Glucosidase by Synthetic Derivatives of Lupane, Oleanane, Ursane and Dammarane Triterpenoids

A variety of new and earlier synthesized lupane, oleanane, ursane and dammarane triterpenoids have been investigated for their inhibitory activity against α-glucosidase. 2,3-Indole-21β-acetyl-20β,28-epoxy-18α,19βH-ursane and 3-oxo-3A-homo-3a-aza-20( S)-hydroxydammar-24(25)-ene were synthesized for the first time. The compounds 3, 4, 8–11 and 14 demonstrated strong in vitro inhibitory activity towards α-glucosidase with IC50 values of 37.5–115.1 μM. 3-Deoxy-3a-homo-3a-aza-28-cinnamoyloxy-20(29)-lupene, with an IC50 of 6.67 μM was 60-fold more active than the market drug acarbose.