Bio-Guided Isolation of Prospective Bioactive Constituents from Roots of Clausena indica (Dalzell) Oliv

Abstract

Clausena indica fruits are routinely used for the culinary purpose as natural spices, whereas leaves and roots are folk medicine with various health benefits in southern China, South and Southeast Asia. In this study, the bioassay-guided fractionation by column chromatography yielded three pure compounds including dentatin, nordentatin, and clausine K and five active fractions (Re1-5) from C. indica roots. These known anticancer compounds were confirmed by X-ray diffraction, 1H-, 13C-nuclear magnetic resonance (NMR), and electrospray ionization tandem mass spectrometric (ESI-MS-MS) analyses. Meanwhile, the phytochemical constituents from fractions were identified by gas chromatography-mass spectrometry (GC-MS). The isolates, fractions’ components and their biological activities were first time investigated on C. indica. By in vitro DPPH and ABTS scavenging assays, nordentatin (IC50 = 49.2 and 69.9 µg/mL, respectively) and the fraction Re4 (32.4 and 38.5 µg/mL, respectively) showed the strongest antiradical activities, whereas clausine K presented a moderate and dentatin had negligible antioxidant activity, respectively. The anti-α-amylase activity of C. indica root extracts was mainly attributed to the fraction Re2 which inactivated the enzymatic assay with IC50 of 573.8 µg/mL. Among tested samples, only nordentatin and clausine K were effective in the pancreatic elastase inhibition, however, their influences were trivial. Markedly, clausine K and Re4 performed the most remarkable tyrosinase inhibition with IC50 values of 179.5 and 243.8 µg/mL, respectively, which were in turn 4 and 3 times stronger than myricetin (IC50 = 735.6 µg/mL), a well-known tyrosinase inhibitor. This is the first report affirming clausine K to be a new strong tyrosinase inhibitor. Isolated compounds from C. indica roots were quantified by high-performance liquid chromatography (HPLC), of which, dentatin, nordentatin, and clausine K accounted for 14.74, 6.14, and 1.28 mg/g dry weight. The findings suggest that bioactive constituents from C. indica roots may be potentially employed for the development of antidiabetic, antiaging and cosmetic agents.

Antioxidant, Anti-tyrosinase, Anti-α-amylase, and Cytotoxic Potentials of the Invasive Weed Andropogon virginicus

“…After that, the enzymatic reaction was inaugurated by supplying 50 µL of L-tyrosine solution. After 10 min of incubation at the same condition, the final solution’s absorbance was recorded at 470 nm [ 72 ]. DMSO and kojic acid were used as negative control and standard inhibitor, respectively.…”

Antioxidant and α-amylase Inhibitory Activities and Phytocompounds of Clausena indica Fruits

“…This anticancer substance can be found in a wide range of Clausena species [19,[28][29][30]. On the other hand, dentatin was isolated and purified from C. indica roots in our previous study, in which, the compound was found to possess a negligible effect on antioxidants and no activity on anti-α-amylase [7]. Therefore, dentatin is not a major substance responsible for the potent biological activities of T4 but might have a role as a co-factor.…”

“…A wide range of phytochemical components can be isolated from the Clausena genus, of which coumarins, carbazole alkaloid, and sesquiterpenes are the most abundant compounds, which might have potential for anticancer activity [3][4][5][6]. In the previous study of Quan et al [7], C. indica roots were announced to have multiple biological activities comprising of antioxidant, anti-α-amylase and anti-tyrosinase. In addition, three pure anti-carcinogenic compounds including dentatin, nordentatin, and clausine K were isolated and purified from C. indica roots [7].…”

“…In the previous study of Quan et al [7], C. indica roots were announced to have multiple biological activities comprising of antioxidant, anti-α-amylase and anti-tyrosinase. In addition, three pure anti-carcinogenic compounds including dentatin, nordentatin, and clausine K were isolated and purified from C. indica roots [7]. Therefore, in this study, the beneficial constituents of C. indica fruits in terms of antioxidants and anti-diabetes are continuously identified.…”

Nutritive Importance and Therapeutics Uses of Three Different Varieties (Murraya koenigii, Micromelum minutum, and Clausena indica) of Curry Leaves: An Updated Review

“…Similarly, the development of antidiabetic agents from C. indica roots has been investigated by bioguided isolation of the ethyl acetate extract. The isolates, dentatin, clausine K, and nordentatin, demonstrate anti- α -amylase activity suggesting the hypoglycemic activity of C. indica roots [ 52 ]. A recent study with ethyl acetate and hexane extracts of C. indica fruit identified coumarins as major compounds demonstrating anti- α -amylase activity [ 53 ].…”