α-Solasonine and α-Solamargine Contents of Gboma (Solanum macrocarpon L.) and Scarlet (Solanum aethiopicum L.) Eggplants

Abstract

The gboma (Solanum macrocarpon L.) and scarlet eggplants (Solanum aethiopicum L.), which form part of the traditional sub-Saharan African culture, are two of the many neglected crops with potential for increased cultivation or as a genetic resource for improving agronomic traits of the common eggplant. This work is focused on the analysis of glycoalkaloid levels in S. macrocarpon and S. aethiopicum to assess their safety. Liquid chromatography-mass spectrometry was used to quantify glycoalkaloids in S. macrocarpon and S. aethiopicum compared to Solanum melongena L. Fruits of S. aethiopicum and S. melongena contained 0.58-4.56 mg/100 g of alpha-solamargine and 0.17-1 mg/100 g of alpha-solasonine, on a wet basis. S. macrocarpon fruits had much higher values of alpha-solamargine (124-197 mg/100 g) and alpha-solasonine (16-23 mg/100 g). However, the proportions of alpha-solamargine and alpha-solasonine of S. melongena and S. macrocarpon were similar (76-89% of alpha-solamargine), whereas in S. aethiopicum fruit composition was more variable (48-89% of alpha-solamargine). According to these results, the glycoalkaloid levels of S. macrocarpon fruits are 5-10 times higher than the value considered to be safe in foods and might not be considered suitable for human consumption; however, the glycoalkaloid levels of S. aethiopicum were similar to those of S. melongena (about 14% of values considered as toxic) and could be considered as safe for consumption. The incorporation of the cultivated African S. aethiopicum into eggplant breeding programs to develop improved varieties of the common eggplant may represent an alternative to crossing with wild species.

Evaluation of Solasonine Content and Expression Patterns of SGT1 Gene in Different Tissues of Two Iranian Eggplant (Solanum melongena L.) Genotypes

“…solamargine and solasonine) (8). The results indicated that the fruits of S. aethiopicum and S. melongena contained (in mg per 100 g of fresh mass) α-solamargine (0.58−4.56) and α-solasonine (0.17−1.0).…”

“…It is also known that SGAs are normally generated in all parts of the eggplant, including the leaves, roots, fruits and sprouts, and that biosynthesis proceeds through the cholesterol pathway (8). However, many steps between cholesterol synthesis and formation of α-solasonine and α-solamargine are unknown.…”

“…In addition, genotypes under study may play a key role, since SGA magnitudes may vary from one cultivar to another (8,17). It has also been reported that various environmental conditions may affect SGA production/accumulation in Solanaceae family (18,19).…”

“…SGAs, as the main factor for producing bitter flavour in the fruits of Solanaceae family like eggplant (7), are believed to play fundamental roles in the defense mechanisms of the plants against pests and phytopathogens. In addition, they may also cause sporadic outbreaks of poisoning and therefore detrimental consequences on human health (4,8,9). In fact, with a lethal dose of 3−5 mg per kg of body mass, SGAs are assumed as potent poisons, similar to arsenic and strychnine (10).…”

Plants from Solanaceae family with possible anxiolytic effect reported on 19th century's Brazilian medical journal

“…Patents that were reported, both in the European Patent Office and the Brazilian National Institute of industrial Property databases, most of which concern inflammatory, allergic, parasitic, infectious or digestive diseases, including extracts from P. angulata (Balbani et al, 2009 (Zakaria et al, 2006); can cause a central nervous system depression which may be correlated with an increased parasympathetic tone (Perez et al, 1998), antioxidant (Al-Fatimi et al, 2007); antipyretic and anticancer agent (Hsieh et al, 2008;Hsu et al, 2009;Yang et al, 2010;Li et al, 2008;Li et al, 2009), mutagenic activity (Almeida et al, 2010). Phytochemical: glycoalkaloids (El-Ashaal et al, 1999), tropane alkaloids (Oksman-Caldentey, 2007;Grynkiewicz & Gadzikowska, 2008;Nash et al, 1993), nicotine alkaloids (Oksman-Caldentey, 2007;Boswell et al, 1999), flavonoids (Wollenweber et al, 2005;Huang et al, 2010), sterols (Amir & Kumar, 2004), steroidal saponins (Ikeda et al, 2000;Nakamura et al, 2008;Zhou et al, 2006;Ferreira et al, 1996), pregnane saponins (Zhou et al, 2007), volatile oils and anthocyanins (Jainu & Devi, 2006), steroidal alkaloids, such as solamargine, solasonine and solanine (Sanchez-Mata, et al, 2010;Cornelius et al, 2010;Suthar & Mulani, 2008;Chen et al, 2010) and deacetoxysolaphyllidine-3-O-β-Dglucopyranoside (Colmenares et al, 2010); phenolic compounds with strong oxidative effects (Mimica-Dukic et al, 2005;Lin et al, 2007;Huang et al, 2010;…”