Secondary Metabolites of Medicinal Plants. Bharat SinghЧитать онлайн книгу.
(25S)-5β-spirostan-3β-ol-3-O-β-D-glucopyranoside (Zhu et al. 2014). Filiasparoside E, filiasparoside F, and filiasparoside G, stachysterone A-20, and A-22-acetonide, along with asparagusin A, filiasparoside A, filiasparoside B, aspafilioside A, aspafilioside B, and filiasparoside C were isolated from the roots of A. filicinus and possessed cytotoxic activity against human breast adenocarcinoma MDA-MB-231 cell line (Wu et al. 2010).
The (25S)-5β-spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-6-O-acetylglucopyranoside, asparagoside A, (25R)-5β-spirostan-3β-ol-3-O-β-D-glucopyranoside, sarsasapogenin, sarsasapogenone, (25S)-neospirost-4-en-3-one, 25S-spirostan-1,4-dien-3-one, stigmasterol, sarsasapogenin M, sarsasapogenin N, (25S)-5β-spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→4)]-β-D-glucopyranoside, (25S)-5β-spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside, (25S)-5β-spirostan-3β-ol-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside, (25S)-26-O-β-D-glucopyranosyl-5β-furost-20-(22)-ene-3β,26-diol 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside, yamogenin, β-sitosterol, and sitosterol-β-D-glucoside as well as asparagusic acid anti-S-oxide methyl ester and asparagusic acid syn-S-oxide methyl ester, 2-hydroxyasparenyn [3′,4′-trans-2-hydroxy-1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-benzene], asparenyn, asparenyol, (±)-1-monopalmitin, ferulic acid, 1,3-O-di-p-coumaroylglycerol, 1-O-feruloyl-3-O-p-coumaroylglycerol, blumenol C, (±)-epipinoresinol, linoleic acid, 1,3-O-diferuloylglycerol, and 1,2-O-diferuloylglycerol were isolated from an ethyl acetate-soluble fraction of the methanol extract of the aerial parts of A. officinalis (Jang et al. 2004; Huang and Kong 2006).
2.14.2 Culture Conditions
Asparagus racemosus is facing the threat of being endangered due to several developmental, seasonal constraints and malpractices involved in its collection and storage. Due to the presence of steroidal sapogenins, the callus cultures of A. racemosus were established on modified MS medium with supplementation of NAA, 2,4-D, and BAP. The 15-day-old callus was harvested and the saponin production was estimated. In comparison, it was found that root calli produced more saponin compared to nodal calli. The 20-fold accumulation of shatavarins was found to be higher in in vitro cell cultures than in wild plants (Pise et al. 2011, 2015). Phosphorus in general is believed to support good growth and differentiation, and the same is true for potassium (Tsutomu and Katsuko 1987). It has also been established that the presence of exogenous additional phosphorus and potassium enhances secondary metabolite production, especially hecogenin, which is also a steroidal saponin (Kar and Sen 1985; Gyulai et al. 1992). Maximum levels of saponins and biomass production were obtained on day 25 of the culture cycle (pH 3.4–5.6). Saponin accumulation was not a biomass-associated phenomenon; cultures that showed the highest biomass accumulation were not the highest saponin accumulators. Maximum biomass and accumulation of shatavarin IV was found in a medium containing 2,4-D and casein hydrolysate and pectinase. The maximum production of sarsasapogenin, secreted and intracellular, accumulated in medium containing NAA, 2,4-D, BAP, casein hydrolysate, and pectinase after 25 days of inoculation (Pise et al. 2012). Fusarium oxysporum, Rhizopus stolonifer as abiotic elicitors, and UV and salicylic acid as abiotic elicitors were used for enhancement of shatavarins in cell cultures of A. racemosus. From this study, it was established that biotic elicitors show mild effects of accumulation of saponins, while abiotic elicitors (salicylic acid and UV) induced maximum accumulation of shatavarins (Pise et al. 2013). When cells of A. racemosus irradiated with UV-B (five minutes), the pH of the culture medium increases by 1.01 units within 10 minutes of irradiation. The UV-B irradiation increases the activity of the enzyme phenylalanine ammonia lyase in comparison to the control, which increased production of shatavarin (Pise and Upadhyay 2015).
References
1 Agrawal, A., Sharma, M., Rai, S.K. et al. (2008). The effect of the aqueous extract of the roots of Asparagus racemosus on hepatocarcinogenesis initiated by diethylnitrosamine. Phytother. Res. 22: 1175–1182.
2 Ahmad, S., Ahmad, S., and Jain, P. (1991). Chemical examination of Shatavari (Asparagus racemosus). Bull. Medico. Ethnobot. Res. 12: 157–160.
3 Bopana,