Cool-cultivated red leaf lettuce accumulates cyanidin-3-O-(6″-O-malonyl)-glucoside and caffeoylmalic acid

Abstract

Cultivating lettuce in greenhouses at low temperatures improves its CO2-balance and may increase its content of flavonoid glycosides and phenolic acids. We cultivated 5weeks old red leaf lettuce seedlings at 20/15°C (day/night) or 12/7°C until plants reached comparable growth stages: small heads were harvested after 13 (warm) and 26 (cool)days, while mature heads were harvested after 26 (warm) or 52 (cool)days. Additionally, some plants were cultivated first cool then warm and vice versa (39days). Cool-cultivated small heads had higher concentrations of cyanidin-3-O-(6″-O-malonyl)-glucoside and caffeoylmalic acid than warm-cultivated ones but we detected no differences concerning quercetin and luteolin glycosides or di-O-caffeoyltartaric and 5-O-caffeoylquinic acid. Regarding mature heads, there were only differences concerning cyanidin-3-O-(6″-O-malonyl)-glucoside. We therefore suggest that only cyanidin-3-O-(6″-O-malonyl)-glucoside was truly responsive to temperatures alone. Previously reported contrasting effects may rather be due to comparison of different growth stages or interactive effects with radiation.

Lettuce Biomass Accumulation and Phytonutrient Concentrations Are Influenced by Genotype, N Application Rate and Location

“…Similarly, the location had a significant impact on individual concentrations of phenolics, resulting in a higher concentration of chicoric acid and C-3-G at the NWREC location. This result aligns with the assertion that phenolic compounds, and specifically, anthocyanins are produced in larger concentrations when crops are grown at cooler temperatures [26,29]. The anthocyanins, C-3-G, were substantially elevated in 'Thurinus' grown under cooler conditions at the NWREC location.…”

Characterization of phenolic compounds in green and red oak‐leaf lettuce cultivars by UHPLC‐DAD‐ESI‐QToF/MS using MSE scan mode

“…MS E experiments in the positive ion mode showed that CMA behaved as described above for CQA, yielding the same ions from the caffeoyl moiety, as well as the sodium adduct. CMA, commonly named as phaseolic acid, has been described before in different lettuce cultivars, and already detected in the red oak‐leaf lettuce cultivar, but in green oak‐leaf lettuce for the first time in the present work.…”

“…In the negative ion mode, both peaks ( 20 , 21 ) yielded the same base peak at m/z 293 due to the loss of water of the deprotonated caffeoyltartaric acid and [CTA − H] − at m/z 311 due to the loss of one of the caffeoyl moieties, as well as ions from the tartaric moiety, [tartaric acid − H] − at m/z 149 and [tartaric acid − H − CO 2 ] − at m/z 105 and ions from the caffeoyl moiety, [caffeic acid − H] − at m/z 179, and [caffeic acid − H − CO 2 ] − at m/z 135. Compound 20 was tentatively identified as di‐ O ‐caffeoyltartaric (chicoric acid), and compound 21 as meso‐di‐ O ‐caffeoyltartaric acid, since they were detected in lettuce elsewhere; the former being reported as the most abundant as we observed, as well in oak‐leaf cultivars …”

“…Lettuce ( Lactuca sativa L.) is one of the most popular leafy vegetables in the world, commonly consumed fresh in salad dishes. Lettuce contains several kinds of phenolic compounds: hydroxycinnamic acids being the most abundant class followed by flavonols, flavones, hydroxybenzoic acids, and anthocyanins . The contents of polyphenols in lettuce tissues are susceptible to high variations among cultivars and growing conditions; indeed anthocyanins have been only detected in red colored cultivars and isoflavones, in iceberg lettuce .…”

Effects of Elevated Temperature and Potassium on Biomass and Quality of Dark Red ‘Lollo Rosso’ Lettuce

“…For example, high light intensity often results in the production of secondary metabolites called anthocyanins in flowering plants. Anthocyanins offer plants additional photoprotection due to the ability to absorb radiation in the photosynthetically active spectrum [34][35][36].…”