RESUMEN
In this study, new indol-fused pyrano[2,3-d]pyrimidines were designed and synthesized. These products were obtained in moderate to good yields and their structures were assigned by NMR, MS, and IR analysis. Afterwards, the biological important of the products was highlighted by evaluating in vitro for α-glucosidase inhibitory activity as well as acetylcholinesterase (AChE) inhibitory activity. Eleven products revealed substantial inhibitory activity against α-glucosidase enzyme, among which, two most potent products 11d,e were approximately 93-fold more potent than acarbose as a standard antidiabetic drug. Besides that, product 11k exhibited good AChE inhibition. The substituents on the 5-phenyl ring, attached to the pyran ring, played a critical role in inhibitory activities. The biological potencies have provided an opportunity to further investigations of indol-fused pyrano[2,3-d]pyrimidines as potential anti-diabetic agents.
Asunto(s)
Inhibidores de la Colinesterasa , Inhibidores de Glicósido Hidrolasas , Acetilcolinesterasa/metabolismo , alfa-Glucosidasas/metabolismo , Inhibidores de Glicósido Hidrolasas/farmacología , Inhibidores de Glicósido Hidrolasas/química , Hipoglucemiantes/farmacología , Simulación del Acoplamiento Molecular , Piranos/farmacología , Piranos/química , Pirimidinas/farmacología , Pirimidinas/química , Relación Estructura-Actividad , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacologíaRESUMEN
A series of nineteen nitrogen-containing lupane triterpenoids was obtained by modification of C2, C3, C20 and C28 positions of betulonic acid and their α-glucosidase inhibiting activity was investigated. Being a leader compound from our previous study, 2,3-indolo-betulinic acid was used as the main template for different modifications at C-(28)-carboxyl group to obtain cyano-, methylcyanoethoxy-, propargyloxy- and carboxamide derivatives. 20-Oxo- and 29-hydroxy-20-oxo-30-nor-analogues of 2,3-indolo-betulinic acid were synthesized by ozonolysis of betulonic acid followed by Fischer indolization reaction. To compare the influence of the fused indole or the seven-membered A-ring on the inhibitory activity, lupane A-azepanones with different substituents at C28 were synthesized. The structure-activity relationships revealed that the enzyme inhibition activity dramatically increased (up to 4730 times) when the carboxylic group of 2,3-indolo-betulinic acid was converted to the corresponding amide. Thus, the IC50 values for glycine amide and L-phenylalanine amides were 0.04 and 0.05⯵M, respectively. This study also revealed that 2,3-indolo-platanic acid is 4.5 times more active than the parent triterpenoid with IC50 of 0.4⯵M. Molecular modeling suggested that improved potency is due to additional polar interactions formed between C28 side chain and a sub-pocket of the α-glucosidase allosteric site.