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A combination of the traditional, Klason lignin and the recently developed derivatization followed by reductive cleavage (DFRC) method is employed for the characterization of the asparagus lignin, which is obtained from the basal sections of fresh and stored spears. The results prove that the nature of a plant highly affects the lignin composition.

In this study, Asparagus stipularis was characterized concerning its phytochemical composition, antioxidant potential, cytotoxicity, and pancreatic lipase inhibitory activities. Twenty-seven compounds were identified and quantified by HPLC-DAD-MS in the leaf, stem, pericarp, and rhizome of ethanolic extracts. Seven steroidal saponins were detected, and the highest content was quantified in rhizome and pericap. A. stipularis also contained significant amounts of flavonoids in the aerial part. Isorhamnetin tetra-glycoside, quercetin-3-glucosyl-rutinoside, and rutin were the main flavonoid derivatives in leaf, stem, and pericarp extracts, respectively. In addition, eleven phenolic acids were also detected; among them, caffeic acid, protocatechuic acid, p-hydroxybenzoic acid, and ferulic acid were the predominant phenolics, with these having the highest amounts quantified in the rhizome extracts. All the tested extracts possessed antioxidant capacities, with pericarp and rhizome extracts exhibiting the highest activity in DPPH, ABTS, and FRAP assays. The extracts from pericarp and rhizome were revealed to also be the strongest inhibitors of pancreatic lipase. The rhizome extracts exhibited potent cytotoxic activity against HCT-116 and HepG2 with IC50 values of 30 and 54 µg/mL after 48 h of treatment. The present study demonstrated that A. stipularis can be used as a new source of natural antioxidants and potential anticancer and antiobesity compounds.

The phytochemical composition of leaves, stems, pericarps and rhizomes ethanolic extracts of Asparagus acutifolius were characterized by HPLC-DAD-MS. A. acutifolius samples contain at least eleven simple phenolics, one flavonon, two flavonols and six steroidal saponins. The stem extracts showed the highest total phenolic acid and flavonoid contents, where cafeic acid and rutin were the main compounds. No flavonoids were detected in the leaf, pericarp or rhizome while caffeic acid and ferulic acid were the predominant. Steroidal saponins were detected in the different plant parts of A. acutifolius , and the highest contents were found in the rhizome extracts. The stem extracts exhibited the highest antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and the highest 2,2-azino-bis (3 ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activity was found in the pericarp extracts. The rhizome and leaf extracts showed a potent cytotoxic activity against HCT-116 and HepG2 cell lines. Moreover, the pericarp and rhizome extracts revealed a moderate lipase inhibitory activity. The leaf and rhizome extracts were screened for their antimicrobial activity against human pathogenic isolates. The leaf extract exhibited a powerful inhibitory activity against all the bacteria and fungi tested.

Colorectal cancer is the third most common cancer in the world. Many efforts have focused on finding natural molecules with potential chemo-preventive activity due to their low toxicity compared to synthetic drugs. However, comprehensive information on the bioactive fractions and components is still missing. In this study, we developed a method for the quantitative separation and isolation of saponins from asparagus genotypes consisting of an adsorption chromatography and subsequent liquid chromatographic separation on a reversed-phase column. The saponins isolated were tested for their cytotoxic activity against human colon cancer cell lines, which could develop cross-resistance to a wide variety of chemotherapeutic drugs. Our results showed that Huétor-Tájar asparagus saponins (HTSAP), mainly protodioscin and HTSAP-10 have higher cytotoxic activity than HTSAP-1, HTSAP-6, and HTSAP-8. This study links the potential anticancer effect of asparagus to specific saponins and unveils the triguero Huétor-Tájar asparagus as a nutraceutical particularly in colon cancer therapies., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

The ethanolic extracts from the leaves, pericarps and rhizomes of Asparagus albus L. were investigated for their phytochemical composition, antioxidant (DPPH and FRAP assays), anti-microbial against human pathogenic isolates and cytotoxic (human colon carcinoma HCT-116 cells) activities. The highest flavonoid content was obtained in the leaf extract followed by the pericarp but there were no flavonoids detected in the rhizome. However, the rhizome had a high concentration of saponins. Flavonoid and saponin profiles were similar to those previously described for the triguero Huetor Tajar asparagus landrace. It was found that the pericarp ethanolic extract exhibited higher antioxidant activity than rhizome and leaf extracts. Moreover, the rhizome possessed more evident cytotoxic activity against HCT-116 cells in comparison to leaf and pericarp. All extracts showed varying degrees of antimicrobial activity against most of the human pathogenic isolates. In addition, the leaves showed more powerful inhibitory activities against the maximum number of bacteria and all the fungai isolated and the highest activity was in the pericarp extract against multidrug resistant Pseudomonas aeruginosa (MDR) and Erythromycin resistant Streptococcus agalactiae (ER) with an inhibition zone of 21mm and 19mm, respectively. The results show that A. albus could be a new crop with pharmaceutical interest because its richness in bioactive compounds provides considerable benefits for human health., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The aim of this work was to study the saponin profiles from spears of different wild asparagus species in the context of its genetic diversity aside from geographical seed origin. They included Asparagus pseudoscaber Grecescu, Asparagus maritimus (L.) Mill., Asparagus brachiphyllus Turcz., Asparagus prostrates Dumort., and Asparagus officinalis L. The saponin analysis by LC-MS has shown that saponin profile from wild asparagus is similar to that previously described for triguero asparagus from Huétor-Tájar landrace (triguero HT), which had not ever been reported in the edible part of asparagus. All the samples, except A. officinalis, were characterized for having saponins distinct to protodioscin and the total saponin contents were 10-fold higher than those described for commercial hybrids of green asparagus. In particular, A. maritimus from different origins were rich in saponins previously found in triguero HT. These findings supported previous suggestion, based on genetic analysis, about A. maritimus being the origin of triguero HT. Multivariate statistics including principal component analysis and hierarchical clustering analysis were used to define both similarities and differences among samples. The results showed that the greatest variance of the tested wild asparagus could be attributed to differences in the concentration of particular saponins and this knowledge could be a tool for identifying similar species., (© 2017 Institute of Food Technologists®.)

Asparagus byproducts are a good source of cationic soluble peroxidases (CAP) useful for the bioremediation of phenol-contaminated wastewaters. In this study, cell wall bound peroxidases (POD) from the same byproducts have been purified and characterized. The covalent forms of POD represent >90% of the total cell wall bound POD. Isoelectric focusing showed that whereas the covalent fraction is constituted primarily by anionic isoenzymes, the ionic fraction is a mixture of anionic, neutral, and cationic isoenzymes. Covalently bound peroxidases were purified by means of ion exchange chromatography and affinity chromatography. In vitro detoxification studies showed that although CAP are more effective for the removal of 4-CP and 2,4-DCP, anionic asparagus peroxidase (AAP) is a better option for the removal of hydroxytyrosol (HT), the main phenol present in olive mill wastewaters.

The main goal of this study was to determine the saponin profiles of different "triguero" asparagus genotypes and to compare them to green asparagus commercial hybrids. The samples consisted of 31 commercial hybrids and 58 genotypes from the Huétor-Tájar (HT) population variety ("triguero"). The saponin analysis by high-performance liquid chromatography-mass spectrometry allowed for the determination of 12 saponins derived from a furostan-type steroidal genin, 4 of which had never been described in the edible part of asparagus. The saponin profile of "triguero" asparagus was a combination of these new saponins and protodioscin. Although protodioscin was the major saponin found in commercial hybrids, some of these 12 saponins were detected as major components in some of the commercial hybrids. The total contents of saponins described in some of these HT genotypes reach values as high as 10-100 times higher than those found in commercial hybrids.

The main goal of this study was the optimization of a HPLC-MS method for the qualitative and quantitative analysis of asparagus saponins. The method includes extraction with aqueous ethanol, cleanup by solid phase extraction, separation by reverse phase chromatography, electrospray ionization, and detection in a single quadrupole mass analyzer. The method was used for the comparison of selected genotypes of Huétor-Tájar asparagus landrace and selected varieties of commercial diploid hybrids of green asparagus. The results showed that while protodioscin was almost the only saponin detected in the commercial hybrids, eight different saponins were detected in the Huétor-Tájar asparagus genotypes. The mass spectra indicated that HT saponins are derived from a furostan type steroidal genin having a single bond between carbons 5 and 6 of the B ring. The total concentration of saponins was found to be higher in triguero asparagus than in commercial hybrids.

Soluble peroxidase (POD) from asparagus byproducts was purified by ion exchange chromatographies, and its kinetic and catalytic properties were studied. The isoelectric point of the purified isoperoxidases was 9.1, and the optimum pH and temperature values were 4.0 and 25 °C, respectively. The cationic asparagus POD (CAP) midpoint inactivation temperature was 57 °C, which favors its use in industrial processes. The Km values of cationic asparagus POD for H₂O₂ and ABTS were 0.318 and 0.634 mM, respectively. The purified CAP is economically obtained from raw materials using a simple protocol and possesses features that make it advantageous for the potential use of this enzyme in a large number of processes with demonstrated requirements of thermostable POD. The results indicate that CAP can be used as a potential candidate for removing phenolic contaminants.