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Abstract

The principal bitter sesquiterpene lactones (BSLs; latucin, 8-deoxylactucin, and lactucopicrin) in six red and four green-pigmented leaf lettuce (Lactuca sativa L. var. crispa L.) cultivars were identified and quantified using high-performance liquid chromatography, proton nuclear magnetic resonance, and liquid chromatography–mass spectrometry and the contribution of each to the overall bitterness was determined. The concentration of each BSL and the total varied significantly among cultivars and there were significant differences resulting from leaf color (green versus red) and morphology (cut versus curled leaves) with red and curled leaf cultivars having higher BSL concentrations. The concentrations of lactucin, 8-deoxylactucin, and lactucopicrin ranged from 2.9 to 17.2, 2.8 to 17.1, and 8.8 to 36.1 mg g–1 dry weight, respectively, with the total concentration ranging from 14.6 to 67.7 mg g–1. Bitterness of the cultivars was assessed using a bitter activity value calculated using the concentration and bitterness threshold value for each BSL. Lactucopicrin was the primary contributor to bitterness as a result of its concentration and lower bitterness threshold; its relative proportion of the total bitterness activity value across all cultivars was over 72%. The concentration of individual BSLs differed with leaf location on the plant (i.e., basal, midstalk, and flower stalk). The concentrations in lactucin, 8-deoxylactucin, and lactucopicrin in flower stalk leaves were significantly higher (i.e., 2.9, 12.4, and 5.4 times, respectively) than in basal leaves, with the concentrations increasing acropetally. Genetic differences among cultivars and with leaf location on the plant contribute to the wide range in bitterness in lettuce.
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... It is usually grown for its leaf, but sometimes for its stem and seeds. In Korea, lettuce is mainly consumed as a salad dish or eaten with sandwiches and meat [3]. In recent years, consumers' interest in lettuce has increased dramatically due to its attractive visual quality, minimum microbial load, and presence of nutritionally important phytoconstituents [1]. ...
... In recent years, consumers' interest in lettuce has increased dramatically due to its attractive visual quality, minimum microbial load, and presence of nutritionally important phytoconstituents [1]. Moreover, lettuce contains several bioactive phytochemicals including, anthocyanins [4], phenolic acids [5,6], flavonoids [5,7], carotenoids, folate, ascorbic acid [8], and sesquiterpene lactones [3,9]. In addition, lettuce plants did show potent allelopathic activity [10]. ...
... SLs are C-15 terpenoids that naturally occur in the form of hydrocarbons, alcohols, ketones, aldehydes, acids or lactones [40]. Lactucin and lactucopicrin, the major SLs reported in lettuce, contribute significantly to the bitterness nature of lettuce cultivars [3,20]. Two bitter sesquiterpene lactones (SLs), lactucin and lactucopicrin, were identified and quantified using HPLC by comparing their retention time and UV/Vis spectra to their corresponding authentic standards. ...
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Background: Identification and screening of cultivars rich in bioactive phytoconstituents can be potentially useful to make nutrient-dense dishes and in medicinal formulations. In this study, we have identified, characterized and quantified caffeoylquinic acids, dicaffeoylquinic acid, dicaffeoyltartaric acid, kaempferol conjugates, quercetin malonylglucoside, sesquiterpene lactones, and cyanidin in 22 lettuce cultivars at mature and bolting stages using UPLC-PDA-Q-TOF-HDMS, UPLC, and HPLC. Results: The composition and contents of the studied metabolites and antioxidant activity varied significantly and depend on leaf color, cultivar type and stage of maturity. The main phenolic acid components of lettuce were quinic and tartaric acid derivatives, whereas kaempferol derivatives were the dominant flavonoids. The sum of the content of phenolic acids ranged from 18.3 to 54.6 mg/100 g DW and 15.5 to 54.6 mg/100 g DW, whereas the sum of the contents of flavonoids ranged from 9.2 to 25.9 mg/100 g DW and 14.9 to 83.0 mg/100 g DW in mature and bolting stage cultivars, respectively. The content of cyanidin, lactucin, lactucopicrin, and ABTS radical antioxidant activity were in the range of 0.3 to 9.7 (mature stage) and 0.5 to 10.2 mg/g DW (bolting stage), 1.8 to 41.9 (mature stage) and 9.7 to 213.0 (bolting stage) µg/g DW, 9.9 to 344.8 (mature stage) and 169.2 to 3888.2 (bolting stage) µg/g DW, and 12.1 to 29.0 (mature stage) and 15.7 to 30.3 (bolting stage) mg TE/g DW, respectively. The principal component analysis (PCA) showed that the green and red pigmented lettuce cultivars were grouped to the negative and positive sides of PC1, respectively, while the green/red pigmented cultivars were distributed throughout the four quadrants of the PCA plots with no prominent grouping. The loading plot showed that phenolic acids, flavonoids, and cyanidin are the most potent contributors to the radical scavenging activity of lettuce extracts. Conclusions: Lettuce at the bolting stage accumulate relatively high amount of sesquiterpene lactones (SLs), quercetin malonylglucoside (QMG), methylkaempferol glucuronide (MKGR), kaempferol malonylglucoside (KMG), and 3-O-caffeoylquinic acid (3-CQA) compared to the mature stage. Higher amount of phytoconstituents were found to be accumulated in the red pigmented lettuce leaves compared to the green lettuce leaves. In addition, the contents of most of the metabolites in lettuce seem to increase with age of the leaves. The presence of the two bitter SLs, lactucin and lactucopicrin, in significantly high amount in lettuce leaves at bolting stage could diminish consumer acceptance. However, alternatively, these leaves could be utilized by nutraceutical companies working to recover these compounds.
... The content depends largely on the species, variety and the part of the plant analyzed. In fact, lettuce guaianolide content was high and reached concentrations between 61.7 mg/mL and 147.1 mg/mL in its latex [160] and 2.9 mg/g to 36.1 mg/g in the overall plant, expressed as dry weight [162]. ...
... These compounds are distributed within Asteraceae like Lactuca serriola [158], especially plants commonly used in salads. Lactuca sativa (lettuce), Cichorium intybus (chicory and radicchio), and Cichorium endivia (endive) have been reported to contain lactucin (7) and lactucin-related substances [159][160][161][162][163][164]. The content depends largely on the species, variety and the part of the plant analyzed. ...
... The content depends largely on the species, variety and the part of the plant analyzed. In fact, lettuce guaianolide content was high and reached concentrations between 61.7 mg/mL and 147.1 mg/mL in its latex [160] and 2.9 mg/g to 36.1 mg/g in the overall plant, expressed as dry weight [162]. The biological activities of lactucin (7) and lactucin-related compounds had already attracted interest at the end of the 19 th century, as they were credited to be responsible for the bitter taste and pharmacological effect of lactucarium or lettuce opium [165]. ...
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Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors' opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.
... Many studies proved that this plant is an essential source in pharmaceutical and health functional foods because of the anti-oxidant, anti-in ammatory, cytotoxic, hepatoprotective, anti-bacterial, anti-diabetic, digestive, diuretic, necrotic, and sedative properties of the plant (Bown, 1995;Choi, Eom, & Kim, 2016;K. H. Kim, Kim, & Lee, 2007;Seo, Yang, Kays, Lee, & Park, 2009;Wang et al., 2003). The plant is rich in nutritional compositions, phenolic compound, avonoids, and sesquiterpene lactones (Ha et al., 2017;J.-M. ...
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Lactuca indica is a undomesticated medicinal crop in the Asteraceae family. Present study was carried out to identify elite genotype for cultivation and breeding improvement of lettuce. Data was recorded for 19 morphological and developmental traits across 38 accessions (Acc). In addition to this, the morphological cluster was compared with the simple sequence repeat (SSR) marker. The genotypic mean square variance was significant for all characters. The higher extent of genotypic and phenotypic coefficient of variation obtained for basal branch, leaf blade width, and node number. The broad-sense heritability (H ² B) ranged from 45.85% (seed length) to 98.59% (node number), whereas genetic advance as a percentage of the mean (GAM%) ranged from 9.33 to 191. Vegetative characters such as node number, plant hight, basal branch were conjugated with high H ² B and high GAM% indicating additive gene effect and selection of these traits based on phenotypic observation is effective for better gain. Reproductive traits, including bolting duration, flowering duration, and seed weight were linked with high H2B, and moderate GAM% trevealing that these traits are amenable to genetic improvement, these traits also showed a significant positive correlation. Acc 55 and 8 showed the best performance for the majority of the attributes could be good material for further research and breeding. In the Wards’ phylogenetic tree of morphological traits, accessions were clustered based on their phenotypic characters rather than the geographic origin. Morphological characteristics showed no or very week corelation with the SSR genotyped data.
... The total content of the bitter sesquiterpene lactones varied significantly between 10 looseleaf cultivars. These included lactucin (0.03-0.17 mg/100 g FW), 8-deoxylactucin (0.03-0.17 mg/100 g FW), and lactucopicrin (0.09-0.36 mg/100 g FW), with the total sesquiterpene lactone concentrations ranging from 0.15 to 0.68 mg/100 g FW (Seo et al., 2009). Lactucin and lactucopicrin accumulated at higher levels in lettuce leaves during the bolting stage than the mature stage. ...
Article
Lettuce is one of the most commonly consumed leafy vegetables worldwide and is available throughout the entire year. Lettuce is also a significant source of natural phytochemicals. These compounds, including glycosylated flavonoids, phenolic acids, carotenoids, the vitamin B groups, ascorbic acid, tocopherols, and sesquiterpene lactones, are essential nutritional bioactive compounds. This review aims to provide a comprehensive understanding of the composition of health-promoting compounds in different types of lettuce, the potential health benefits of lettuce in reducing the risks of chronic diseases, and the effect of preharvest and postharvest practices on the biosynthesis and accumulation of health-promoting compounds in lettuce.
... 4 Tanaman ini memiliki banyak khasiat dalam pengobatan penyakit karena kandungan senyawa flavonoid, glikosida, saponin, tanin, triterpenoida/steroida, kardenolin, dan polifenol yang tinggi pada ekstrak daun, batang dan akar tanaman 5-9 berpotensi sebagai antioksidan, antibakteri, antidiabetes, meredakan penyakit lambung serta resiko kanker. [10][11][12] Penggunaan obat-obatan herbal sangat efektif digunakan dalam pengobatan dibandingkan dengan obat kimia karena menimbulkan lebih sedikit efek samping. 13 ...
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Have been carried out Phytochemical screening on Sijukkot which determited as Lactuca indica L, the plant from Gibeon hill forrest area in the village of Parsaora Sibisa Ajibata, Toba Samosir, North Sumatera. Test carried out to determine the composition of secondary metabolites contained in these plants. It was started by extracting plant leaves using 96% ethanol solvent which was carried out by maceration method and concentrated using a rotary evaporator. The concentrated extract obtained was sponsored by phytochemical tests. Phytochemical test results on ethanol extracts from the leaves of the Sijukkot plant were obtained compositions namely Flavonoids, tannins, saponins, steroids and triterpenoids.
... These values differed from other results 20 reporting that LcTOT and LpTOT ratios were 77% and 22% in curly vs 82% and 16 % in smooth endives. Several factors may be evoked to explain these discrepancies including diversity of cultivars, leaf types and their positon in the rosette, cultivation and environmental conditions, which influence STL leaf content and composition of endive-related species such as chicory and lettuce 67,68 . Although sensory analyses were beyond the scope of this work, predicted bitterness based on STL perception thresholds 18 distinguished curly from smooth types, consistently with taste based bitterness indices of endive 20 . ...
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Endives (Cichorium endivia L.) are popular vegetables, diversified into curly/frisée- and smooth/broad-leafed (escaroles) cultivar types (cultigroups), and consumed as fresh and bagged salads. They are rich in sesquiterpene lactones (STL) that exert proven function on bitter taste and human health. The assembly of a reference transcriptome of 77,022 unigenes and RNA-sequencing experiments were carried out to characterize the differences between endives and escaroles at the gene structural and expression levels. A set of 3177 SNPs distinguished smooth from curly cultivars, and an SNP-supported phylogenetic tree separated the cultigroups into two distinct clades, consistently with the botanical varieties of origin (crispum and latifolium, respectively). A pool of 699 genes maintained differential expression pattern (core-DEGs) in pairwise comparisons between curly vs smooth cultivars grown in the same environment. Accurate annotation allowed the identification of 26 genes in the sesquiterpenoid biosynthesis pathway, which included several germacreneA synthase, germacreneA oxidase and costunolidesynthase members (GAS/GAO/COS module), required for the synthesis of costunolide, a key precursor of lactucopicrin- and lactucin-like sesquiterpene lactones. The core-DEGs contained a GAS gene (contig83192) that was positively correlated with STL levels and recurrently more expressed in curly than smooth endives, suggesting a cultigroup-specific behavior. The significant positive correlation of GAS/GAO/COS transcription and STL abundance (2.4-fold higher in frisée endives) suggested that sesquiterpenoid pathway control occurs at the transcriptional level. Based on correlation analyses, five transcription factors (MYB, MYB-related and WRKY) were inferred to act on contig83192/GAS and specific STL, suggesting the occurrence of two distinct routes in STL biosynthesis.
... It is thought to be due to the small amount of lactucin in romaine lettuce itself and extraction method might affect the lactucin detection. Seo et al. 32) identified lactucin from the extracts of some lettuce cultivars using methanol. However, its level was much lower than the other sesquiterpene such as lactucopicrin. ...
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The aim of this study is to investigate the effects of romaine lettuce leaves extract (RE), skullcap root extract (SE) and their mixture on sleep behaviors in vertebrate models. HPLC analysis showed that RE contains lactucopicrin (0.02±0.01 mg/g extract), chlorogenic acid (4.05±0.03 mg/g extract), caffeic acid (2.38±0.03 mg/g extract), and chicoric acid (7.02±0.32 mg/g extract) as main phenolic compounds, while SE includes baicalin (99.4±0.5 mg/g extract), baicalein (8.28±0.21 mg/g extract), and wogonin (3.09±0.32 mg/g extract). The mixture of RE (100 mg/g extract) and SE (40 mg/g extract) increased total sleep time by 50.9% compared with the control in pentobarbital-induced sleep model. In electroencephalography (EEG) analysis, RE/SE mixture significantly increased Non-Rapid Eye Movement (NREM), in which delta wave was enhanced by around 40% compared with normal control, leading to the increase of sleep time. In caffeine-induced wake model, RE/SE mixture greatly decreased (53%) caffeine-induced wake time, showing a similar level to normal control. In addition, caffeine-induced decreased of NREM and delta wave effectively increased with RE/SE mixture; NREM and delta wave increased by 85% and 108%, respectively. Furthermore, RE/SE mixture was shown to bind to a gamma-aminobutyric acid type A (GABAA)-benzodiazepine (BZD) receptor stronger than RE or SE single extract. Taken together, RE/SE mixture effectively improved sleep behavior with the increase of NREM via GABAA-BZD receptor binding. RE/SE mixture can be used as an herbal agent for sleep disorders. Graphical Abstract Fullsize Image
... Compared with hydroponically grown lettuce, the accumulation of sesquiterpene lactones and phenolics was markedly greater in BR-and RF-lettuce leaves harvested after soil cultivation. Seo et al. (2009) reported that the correlation between mineral nutrients intake and producing of sesquiterpene lactones in leaf lettuce. Exposure to short-wavelength light (blue LED and UV-B treatments) elicits an increase in phenolics, flavonoids, and the pigment content in lettuce leaves (Ouzounis et al., 2015) and in Arabidopsis thaliana (Kusano et al., 2011c) and our light conditions may have exerted a similar effect. ...
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Samples of red-coloured lettuce and chicory were assessed for bitterness by sensory analysis and compared with conventional green-coloured varieties. The amounts of the sesquiterpene lactones lactucin, 8-deoxylactucin and lactucopicrin and their glycosides were determined using enzyme hydrolysis and high performance liquid chromatography. The level of each of these compounds was compared with the bitterness score found for each sample, and the resulting correlation data suggested that the increasing level of one of these compounds, lactucin glycoside, was closely related to the increase in bitterness.
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 One of the quality parameters of chicory (Cichorium intybus L.) is its slightly bitter taste which is caused by sesquiterpene lactones. As the quality of chicons is highly dependent on the quality of the roots, the effects of the cultivation conditions of the roots on the levels of sesquiterpene lactones in chicons were investigated. Roots from a collection of 11 commercially available and 2 experimental chicory cultivars were grown at five different locations with two nitrogen manuring levels to evaluate the differences in sesquiterpene lactone levels as measured with enzyme-linked immunosorbent assays (ELISAs). There were significant differences (P<0.001) between cultivars in both lactucopicrin and lactucin-like (lactucin, 8-deoxylactucin and their 11β,13-dihydro derivatives) sesquiterpene lactone levels. In addition, a significant (P=0.006 and P=0.019, respectively) effect of additional nitrogen manuring was observed on the levels of lactucopicrin and lactucin-like sesquiterpene lactones. The interaction of cultivar with nitrogen manuring had a significant (P=0.013) effect on the level of lactucin-like sesquiterpene lactones. Furthermore, the lactucopicrin level was significantly influenced by the interactions of the cultivar with the nitrogen manuring level (P<0.001), with the location (P=0.001) and with both the nitrogen manuring level and location (P<0.001). The results indicate that it may be possible to influence the level of the bitter sesquiterpene lactones and, consequently, to influence the taste of chicons by cultivar choice and/or cultivation location and conditions.
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Biosynthetic studies of the guaianolide-type sesquiterpene lactones 11βH,13-dihydrolactucin-8-O-acetate and 8-desoxylactucin were performed in Agrobacterium rhizogenes—transformed hairy root cultures of blue-flowered lettuce, Lactuca floridana. The 13C NMR spectra of the two guaianolides labelled by incorporation of [1-13C], [2-13C], [1,2-13C2]acetate and [2-13C]mevalolactone showed patterns of enrichment consistent with a previously proposed biogenetic pathway for guaianolide-type sesquiterpene lactones via the acetate-mevalonate-germacradiene route.
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Proper nutrient solution management in the root zone is the first consideration for the adoption of a closed hydroponic system. Plant roots often exude numerous organic acids, which are known to inhibit growth. To investigate the accumulation of these phytotoxic organic acids as root exudates, lettuce (Lactuca sativa L.) was hydroponically grown in reused nutrient solution. Organic acids were extracted with diethyl ether from the reused nutrient solutions (RNS), root residues, and activated charcoal (AC) then quantified by GC/MS. Five individual organic acids were identified from the root residues and seven from the reused nutrient solutions. After 90 days of lettuce cultivation, in the treated AC in 3RNS, benzoic, phenylacetic, cinnamic, p-hydroxybenzoic, lauric, phthalic, vanillic, palmitic, and stearic acids were identified. In contrast, little or no organic acids were detected in the 3RNS treated with AC (3RNS/AC). Artificially applied pure organic acids ranging from 25 to 200 μM inhibited lettuce growth in a concentration-dependent manner. Lettuce growth was also greatly reduced in the nutrient solutions containing a externally applied, simulated mixture of the organic acids as in the 3RNS. Lettuce growth was not inhibited following the addition of AC (2.5 g/L) to the nutrient solution containing the mixture of organic acids. Our results demonstrated that organic acids were accumulated in reused nutrient solutions and were phytotoxic to lettuce growth. Also, this study showed that the addition of AC reduces the phytotoxic effects by eliminating the organic acids.
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Five known and one new sesquiterpene lactones were isolated from fresh chicory roots (Cichorium intybus). The new compound 11(S),13-dihydrolactucopicrin was identified by UV, 1H NMR, 13C NMR, and mass spectroscopy. The extraction procedure and HPLC analysis of sesquiterpene lactones in chicory were improved. The bitterness detection thresholds of all compounds were individually determined by triangle testing. 11(S),13-Dihydrolactucopicrin was extremely bitter, with a threshold level of 0.2 ppm. Four other lactones showed threshold values similar to that of quinine hydrochloride.
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The forage potential of chicory (Cichorium intybus L.) has not been realized in southern West Virginia (WV) because ruminants are reluctant to consume the herbage. Chicory contains bitter sesquiterpene lactones that can adversely impact palatability. This study was undertaken to determine whether sesquiterpene lactone concentrations in chicory grown in southern WV differ from those in chicory grown in central Pennsylvania (PA) where chicory is grazed readily. Herbage was collected in 1997 and 1998 from cultivars Grasslands Puna (Puna), INIA le Lacerta (Lacerta), and Forage Feast established at research sites near State College, PA, and Beckley, WV. The total concentration of sesquiterpene lactones in WV-grown cultivars was 0.58% (dry matter basis) in Puna, 0.59% in Lacerta, and 0.79% in Forage Feast in 1997 and ranged from 1.03 (Lacerta) to 1.52% (Forage Feast) in 1998. In PA-grown cultivars, sesquiterpene lactones represented 0.16 (Puna), 0.18 (Lacerta), and 0.27% (Forage Feast) of the forage dry matter in 1997 and ranged from 0.32 (Lacerta) to 0.55% (Forage Feast) in 1998. Concentrations of lactucin, lactucopicrin, and total sesquiterpene lactones in Forage Feast exceeded those in the other cultivars grown at the same site. The lowest concentrations of lactucopicrin and total sesquiterpene lactones observed among WV-grown cultivars were higher (2-fold or more) than the highest concentrations present in cultivars grown the same year in PA. Mineral analyses of soils from the two cultivation sites indicate that P availability may influence sesquiterpene lactone composition of chicory herbage. Results provide a foundation for future studies of environmental effects on sesquiterpene lactone composition and palatability of chicory herbage.
Quantification of chicory root bittemess by an ELISA for II beta
  • P Hance
  • Y Martin
  • J Vasseur
  • J L Hilbert
  • F Trotin
Hance, P., Y. Martin, J. Vasseur, J.L. Hilbert, and F. Trotin. 2007. Quantification of chicory root bittemess by an ELISA for II beta, 13-dihydrolactucin. FoodChcm. 105:742-748.