Rapid investigation of α-glucosidase inhibitory activity of Phaleria macrocarpa extracts using FTIR-ATR based fingerprinting

Phaleria macrocarpa, known as “Mahkota Dewa”, is a widely used medicinal plant in Malaysia. This study focused on the characterization of α-glucosidase inhibitory activity of P. macrocarpa extracts using Fourier transform infrared spectroscopy (FTIR)-based metabolomics. P. macrocarpa and its extracts contain thousands of compounds having synergistic effect. Generally, their variability exists, and there are many active components in meager amounts. Thus, the conventional measurement methods of a single component for the quality control are time consuming, laborious, expensive, and unreliable. It is of great interest to develop a rapid prediction method for herbal quality control to investigate the α-glucosidase inhibitory activity of P. macrocarpa by multicomponent analyses. In this study, a rapid and simple analytical method was developed using FTIR spectroscopy-based fingerprinting. A total of 36 extracts of different ethanol concentrations were prepared and tested on inhibitory potential and fingerprinted using FTIR spectroscopy, coupled with chemometrics of orthogonal partial least square (OPLS) at the 4000–400 cm−1 frequency region and resolution of 4 cm−1. The OPLS model generated the highest regression coefficient with R2Y = 0.98 and Q2Y = 0.70, lowest root mean square error estimation = 17.17, and root mean square error of cross validation = 57.29. A five-component (1+4+0) predictive model was build up to correlate FTIR spectra with activity, and the responsible functional groups, such as –CH, –NH, –COOH, and –OH, were identified for the bioactivity. A successful multivariate model was constructed using FTIR-attenuated total reflection as a simple and rapid technique to predict the inhibitory activity

Analyses and profiling of extract and fractions of neglected weed mimosa pudica Linn. traditionally used in Southeast Asia to treat diabetes

Mimosa pudica Linn. var. hispida Bren. (Family: Fabaceae) a neglected weed has been studied for its antidiabetic potential to propose alternative medicinal source against the global threat of diabetes mellitus. This study aimed to investigate in vitro inhibitory activity against diabetic enzymes (i.e. α-amylase & α-glucosidase) and three anti-oxidant assays were conducted to evaluate anti-diabetic potential of M. pudica’s methanol extract (MeOHi) and its sub-fractions (Hexanef, EtOAcf, Acetonef and MeOHf). In depth chemical profiling using GC Q-TOF MS was also performed for the first time for this weed, to assess the probable compounds present in the extract and sub fractions that could be linked to anti-diabetic activity. Results showed the lowest (7.18±0.0005) and highest (158.4±0.0004) IC50 for DPPH assay by MeOHi andMeOHf, respectively. Acetonef andMeOHi showed the highest TPC (60.07±1.066) and TFC (16.97± 1.472), respectively. Three and two fold higher inhibitory activity than the standard acarbose at 1mg/ mL wasmanifested byMeOHi (95.65±0.911) & EtOAcf (51.87±3.106), respectively. Hexanef did not show inhibitory activity against both the enzymes. α-glucosidase results for the extract and sub fractions were found to be significant (p b 0.05). GC Q-TOF MS analysis identified organic acids, quinolones, quinone, phenolic compounds and dodecaborane as major constituents. Presence of highly radical scavenging dodecaborane is being reported for the first time in M. pudica. High TPC and TFC values could be attributed to exert enzyme inhibitory action byM. pudica that can help in the regulation of glucose absorption and consequently glucose homeostasis. Results show that M. pudica can be proposed as an excellent alternative for future antidiabetic implications