Piret Saar-Reismaa

Dr. Piret Saar-Reismaa

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 March 2023 in Molecules
Verified
Journal Article
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PLPille-Riin Laanet
Pille-Riin Laanet
PSPiret Saar-Reismaa
Piret Saar-Reismaa
PJPiia Jõul
Piia Jõul
OBOlga Bragina
Olga Bragina
MVMerike Vaher
Merike Vaher
The aim of the present study was to examine three different Galium species from the native population of Estonia, Galium verum, Galium aparine, and Galium mollugo, to characterise their non-volatile and volatile phytochemical composition and antioxidant activity. The main groups of bioactive compounds in the plants were quantified by colorimetric tests, showing high concentrations of polyphenols (up to 27.2 ± 1.5 mg GAE/g), flavonoids (up to 7.3 ± 0.5 mg QE/g) and iridoids (up to 40.8 ± 2.9 mg AE/g). The species were compared using HPLC-DAD-MS/MS, revealing some key differences in the phytochemical makeup of the extracts. The most abundant compound in the extracts of Galium verum blossoms and herb was found to be asperuloside, in Galium aparine herb, asperulosidic acid, and in Galium mollugo herb, chlorogenic acid. Additionally, the composition of volatile compounds was analysed by SPME-GC-MS. The degree of variability between the samples was high, but three volatiles, hexanal, anethole, and β-caryophyllene, were quantified (≥1%) in all analysed samples. The antioxidative activity of all extracts was evaluated using the ORACFL method, demonstrating that the Galium species from Estonia all exhibit strong antioxidant capacity (up to 9.3 ± 1.2 mg TE/g). Out of the extracts studied, Galium verum blossoms contained the highest amounts of bioactives and had the strongest antioxidant capacity.

13 July 2022 in Journal of Chromatography A
Verified
Journal Article
Closed access
PSPiret Saar-Reismaa
Piret Saar-Reismaa
MKMihkel Koel
Mihkel Koel
RTRiin Tarto
Riin Tarto
MVMerike Vaher
Merike Vaher

14 December 2020 in Foods
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Journal Article
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PSPiret Saar-Reismaa
Piret Saar-Reismaa
KKKatrin Kotkas
Katrin Kotkas
VRViive Rosenberg
Viive Rosenberg
MKMaria Kulp
Maria Kulp
MKMaria Kuhtinskaja
Maria Kuhtinskaja
MVMerike Vaher
Merike Vaher
The use of colored tubers of Solanum tuberosum L. is growing worldwide due to their health benefits and attractive color. The positive health effects of purple-fleshed tubers are a result of anthocyanins and various phenolic compounds. The aim of this study was to evaluate and compare variety Blue Congo and its cross-breeds of Desiree and Granola to yellow-fleshed tubers. The concentration of total phenols, anthocyanins, sugars, and mineral elements were evaluated in all tubers. The results showed differences between all tested materials, with largest differences in sugar content. Moreover, the results confirmed the preservation of health improving compounds of Blue Congo when cross-bred with yellow-fleshed tubers. The total phenolic content and anthocyanin concentrations of all analyzed tubers were above the comparison yellow ones.

27 April 2017 in Analytical Methods
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Journal Article
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PSPiret Saar-Reismaa
Piret Saar-Reismaa
MVM. Vaher
M. Vaher
MKM. Kaljurand
M. Kaljurand
MKM. Kulp
M. Kulp
JMJekaterina Mazina-Šinkar
Jekaterina Mazina-Šinkar
The aim of the study was to develop a methodology for the determination of γ-hydroxybutyric acid (GHB), ibotenic acid (IBO) and psilocybin (PY) abuse in human saliva. Capillary electrophoresis with a capacitively coupled contactless conductivity detector (CE-C4D) was used with an optimized background electrolyte (BGE) consisting of 17.9 mM L-arginine (Arg), 9.6 mM succinic acid (Suc) and 0.0019% (w/v) hexadimethrine bromide (HDMB) with an adjusted pH of 7.3. Saliva samples were spiked with all three analytes of interest as well as the internal standard, before protein precipitation with acetonitrile (ACN) (1 : 2, v/v, saliva : ACN). The limits of detection (LOD) and quantification (LOQ) in the saliva were 1.5 and 5.0 mg L−1 for GHB, 2.1 and 7.9 mg L−1 for IBO and 3.6 and 12.0 mg L−1 for PY. The intraday precision varied from 0.7% to 8.6% and interday precision from 3.9% to 11.4% for all substances. The overall accuracy and combined recovery were from 95% to 123% and 98% to 103%, respectively. The present study demonstrates that the use of oral fluid as an alternative sample matrix which is easy and fast to collect and prepare, and in combination with a portable CE instrument built in-house, provides rapid and efficient determination of psychoactive substance intoxication.

12 January 2022 in Pharmaceuticals
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PSPiret Saar-Reismaa
Piret Saar-Reismaa
OBOlga Bragina
Olga Bragina
MKMaria Kuhtinskaja
Maria Kuhtinskaja
IRIndrek Reile
Indrek Reile
PLPille-Riin Laanet
Pille-Riin Laanet
MVMerike Vaher
Merike Vaher
Lyme disease (LD) is a tick-borne bacterial disease that is caused by Borrelia burgdorferi. Although acute LD is treated with antibiotics, it can develop into relapsing chronic form caused by latent forms of B. burgdorferi. This leads to the search for phytochemicals against resistant LD. Therefore, this study aimed to evaluate the activity of Dipsacus fullonum L. leaves extract (DE) and its fractions against stationary phase B. burgdorferi in vitro. DE showed high activity against stationary phase B. burgdorferi (residual viability 19.8 ± 4.7%); however, it exhibited a noticeable cytotoxicity on NIH cells (viability 20.2 ± 5.2%). The iridoid-glycoside fraction showed a remarkable anti-Borrelia effect and reduced cytotoxicity. The iridoid-glycoside fraction was, therefore, further purified and showed to contain two main bioactives—sylvestrosides III and IV, that showed a considerable anti-Borrelia activity being the least toxic to murine fibroblast NIH/3T3 cells. Moreover, the concentration of sylvestrosides was about 15% of DE, endorsing the feasibility of purification of the compounds from D. fullonum L. leaves.

13 August 2021 in Molecules
Verified
Journal Article
Open access
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MKMihkel Kaljurand
Mihkel Kaljurand
PSPiret Saar-Reismaa
Piret Saar-Reismaa
MVMerike Vaher
Merike Vaher
JGJelena Gorbatsova
Jelena Gorbatsova
JMJekaterina Mazina-Šinkar
Jekaterina Mazina-Šinkar
Flow analysis is the science of performing quantitative analytical chemistry in flowing streams. Because of its efficiency and speed of analysis, capillary electrophoresis (CE) is a prospective method for the monitoring of a flow composition withdrawn from various processes (e.g., occurring in bioreactors, fermentations, enzymatic assays, and microdialysis samples). However, interfacing CE to a various flow of interest requires further study. In this paper, several ingenious approaches on interfacing flow from various chemical or bioprocesses to a capillary electrophoresis instrument are reviewed. Most of these interfaces can be described as computer-controlled autosamplers. Even though most of the described interfaces waste too many samples, many interesting and important applications of the devices are reported. However, the lack of commercially available devices prevents the wide application of CE for flow analysis. On the contrary, this fact opens up a potential avenue for future research in the field of flow sampling by CE.