Structural Identification and Bioactivities of Red-Violet Pigments Present in Basella alba Fruits

Abstract

Mature Basella alba L. fruit, with dark blue skin and deep red-violet flesh, is a potential source of natural colorants. Its pigment components and bioactivities deserve particular attention and investigation. In this study, fruit flesh was extracted with 80% methanol (containing 0.2% formic acid) and subjected to solid-phase extraction, semipreparative HPLC isolation, mass spectrophotometric analysis, and structural elucidation. The major red pigment was identified as gomphrenin I. Its quantity increased with the increase of fruit maturity. The gomphrenin I extract yield from ripe fruits was 36.1 mg/100 g of fresh weight. In addition to gomphrenin I, betanidin-dihexose and isobetanidin-dihexose were also detected. The antioxidant activities of gomphrenin I determined by Trolox equivalent antioxidant capacity (TEAC), α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and antioxidative capacity assays were equivalent to 534 μM Trolox, 103 μM butylated hydroxytoluene (BHT), 129 μM ascorbic acid, and 68 μM BHT at 180, 23, 45, and 181 μM, respectively. The anti-inflammatory function was tested at concentrations of 25, 50, and 100 μM in murine macrophages stimulated with lipopolysaccharide (LPS). The results revealed that gomphrenin I suppressed LPS-induced nitric oxide (NO) production in a dose-dependent manner and decreased PGE(2) and IL-1β secretions at the highest concentration tested. The transcriptional inhibitory activities of gomphrenin I on the expression of inflammatory genes encoding iNOS, COX-2, IL-1β, TNF-α, and IL-6 were also observed. It is of merit to identify gomphrenin I as a principal pigment of B. alba fruits and as a potent antioxidant and inflammatory inhibitor. These findings suggest that B. alba fruit is a rich source of betalains and has value-added potential for use in the development of food colorants and nutraceuticals.

Characterization of major betalain pigments -gomphrenin, betanin and isobetanin from Basella rubra L. fruit and evaluation of efficacy as a natural colourant in product (ice cream) development

“…), followed by intermediate (87.71± 5.37) and early stage fruits having lowest (22.32±1.56). According to Lin et al (2010), the major betalain pigment characterized in B. alba fruits was gomphrenin I the concentration of which increases on fruit maturity. The gomphrenin I pigment content quantified by HPLC was 26.06, 2.15 and 0.23 mg/100 g fresh weight of fruits in ripened, intermediate and early stage respectively ( Fig.…”

“…Twenty micro liters of extract were injected, and mobile phase consists of (A) 0.1 % trifluoro acetic acid in water and (B) 100 % methanol. The binary gradient solvent program was set at 0 min, 85 % A and 15 % B; 10 min, 70 % A and 30 % B; 15 min, 20 % A and 80 % B; 17 min, 10 % A and 90 % B; 25 min, 9 % A and 91 % B; 26 min, 0 % A and 100 % B; and 28 min, 85 % A and 15 % B, with a flow rate of 1.0 ml/min (Lin et al 2010). …”

“…Deseeded fruits were weighed (1.0:10w/v) and homogenized in distilled water using mortar and pestle and centrifuged at 12,000 rpm for 10 min at 4°C. The collected supernatant was further analyzed for its absorbance maxima of pigments using spectrum from 400 to 600 nm, pigment quantity and characterization by photometrically according to Castellanos-Santiago and Yahia (2008) and HPLC method (Lin et al 2010). All the measurements were made in triplicates.…”

“…Three to four months old plant produce approximately 2 kg of fresh fruits. Lin et al (2010) identified the red violet pigments present in B. alba and B. rubra fruits.…”

“…Betalains are nitrogen containing plant pigment which replaces anthocyanins in flowers and fruits of plants of family Caryophyllales (Clement and Mabry 1996). The other sources of betalains are beet root, Gomphrena globosa flowers, amaranth plant, Rivina humilis fruits and cactus fruits (Lin et al 2010;Khan et al 2012;Khan and Giridhar 2014a). Betalains may be orange to yellow betaxanthins and red to violet betacyanins, which can be classified into four types based on their chemical structure such as betanin type, amaranthin type, gomphrenin type and bouganvillein type (Cai et al 2005).…”