In this study, the ability of Nepeta cataria L. to grow and synthesize bioactive compounds on soil treated with different salt concentrations was tested to evaluate the opportunity of cultivating it in soils affected by salinization. N. cataria L. was grown in soil containing specific amounts of NaCl, Na2SO4, and their mixture. After harvesting, the plants were analyzed from the morphological and physiological point of view. Salinity stress inhibited the growth, with the highest decrease of the plant yield up to about 70% in the case of salt mixture, and smaller values for the separate salt treatments. In the same time, as a defense mechanism, there was an increase of granular trichomes’ density, as observed with the scanning electron microscope. For mild concentrations of salt, the amount of chlorophyll pigments was enhanced, while for stronger salinity stress, it decreased. The opposite behavior was evidenced for the polyphenol content, as antioxidant activity was used as a protective mechanism against reactive oxygen species produced under salinity stress. The antioxidant activity was considerably higher for separate NaCl and Na2SO4 treatments than for the salt mixture variants. The results showed that the species Nepeta cataria L. reacts well to high salinity levels, with an increased content of bioactive compounds and antioxidant activity even for the highest studied salinity conditions.

In this work, the effects of salt stress on Nepeta racemosa Lam. were studied to analyze the possibility of using it as a potential culture for salinity-affected soils. A total of nine concentrations of salts—NaCl (18, 39, and 60 mg/100 g soil), Na2SO4 (50, 85, and 120 mg/100 g soil), and a mixture (9 g NaCl + 25 g Na2SO4, 19 g NaCl + 43 g Na2SO4, and 30 g NaCl + 60 g Na2SO4/100 g soil)—simulated real salinity conditions. Environmental electron microscopy offered information about the size and distribution of glandular trichomes, which are very important structures that contain bioactive compounds. The chlorophyll pigments, polyphenols, flavonoids, and antioxidant activity were determined based on spectrophotometric protocols. The results have shown a different impact of salinity depending on the salt type, with an increase in bioactive compound concentrations in some cases. The highest polyphenol concentrations were obtained for Na2SO4 variants (47.05 and 46.48 mg GA/g dw for the highest salt concentration in the first and second year, respectively), while the highest flavonoid content was found for the salt mixtures (42.77 and 39.89 mg QE/g dw for the highest concentrations of salt in the first and, respectively, the second year), approximately 100% higher than control. From the Pearson analysis, strong correlations were found between chlorophyll pigments (up to 0.93), antioxidant activity and yield for the first harvest (up to 0.38), and antioxidant activity and flavonoid content for the second harvest (up to 0.95). The results indicate the possibility of growing the studied plants in salt-stress soils, obtaining higher concentrations of bioactive compounds.

The purpose of this study was to evaluate some elements of physiology and biochemistry in Nepeta racemosa Lam. in the pedo-climatic conditions of the Moldavian forest steppe. The parameters were quantified under conditions of differentiated fertilisation with three foliar products (KSC 1, KSC 2, and Corona K). Biochemical analysis by GC/MS revealed the highest concentration of the following components: nepetallic acid (Untreat - 54.33%, KSC 1 - 55.50%, KSC 2 - 56.90%, Corona K - 53.77), eucalyptol (Untreat . 9.87%, KSC 1 - 10.70%, KSC 2- 12.80%, Corona K - 10.78%), 3-hydroxy-(4S, 4aS, 7S, 7aS)-dihydronepetalactone (Untreat - 5.87%, KSC 1 - 5.37%, KSC 2 - 4.87, Corona K - 3.67%), and (4aS, 7S, 7aS)-trans, cis-nepetalactone (Untreat - 4.30%, KSC 1 - 5.00%, KSC 2 - 4.20%, Corona K - 5.23%). Polyphenols were present in large quantities in the Corona K variant, with 33.1 mg GA/g dw at the first harvest and 27.88 mg GA/g dw at the second harvest. The highest concentration of flavonoids was identified in the Corona K variant (26.34 mg QE/g dw - first harvest and 56.77 mg QE/g dw - second harvest). The antioxidant activity was between 14.76 and 38.54% at the first harvest, and from 12.18 to 22.95% at the second harvest. Chlorophyll pigments ranged from 13.12-17.68 μg/ml-1 for chlorophyll a, 5.43-9.66 μg/ml-1 for chlorophyll b, and 2.07-3.34 μg/ml-1 for carotenoids. The highest grass production per m2 was achieved in the version fertilised with KSC 1 for both crops, with 986.66 g/m2 for the first harvest and 861.33 g/m2 for the second. Iridoids are a class of substances that are commonly used for pesticide role. The study aims to highlight these substances and determine whether differentiated fertilization influences. The presented data confirm the results in the literature for polyphenols and flavonoids, but also present chemotypic novelties in terms of chemical composition and represent a direction to follow for future research.

Essential oil of Nepeta racemosa Lam. was extracted and characterized to determine its antimicrobial activity and potential use in applications. The essential oil was loaded on polyvinyl alcohol-pullulan films and gels and characterized by optical microscopy, scanning electron microscopy, and UV-Vis spectroscopy before having its antimicrobial capacities assessed. The essential oil extracted from Nepeta racemosa Lam. was characterized using gas chromatography coupled with mass spectroscopy, which indicated that the most abundant component was nepetalic acid (55.5%), followed by eucalyptol (10.7%) and other compounds with concentrations of about 5% or less. The essential oil, as well as the loaded films and gels, exhibited good antibacterial activity on both gram-positive and gram-negative strains, with growth inhibition zones larger in some cases than for gentamicin, indicating excellent premises for using these essential-oil-loaded materials for applications in the food industry or biomedicine.

Some doses of compost obtained in farms were tested during 2004-2006, comparative to chemical fertilization, at S.C. Şoimul S.R.L. from Vacareni Plain, Jijila village, Tulcea district. It was found out that fertilization with 30 t/ha of compost had established the highest production of wheat Dropia variety, 6512 kg/ha, with 40.7 % higher than unfertilized variant and 16.8 % higher than N160P80K80 fertilized variant. The highest protein content of 15.21% has been obtained in the case of using the chemical fertilizing with N 160 P 80 K 80 , followed by 14.91% when 30 t/ha of compost was applied for fertilization of soil. Also, the content in wet gluten was 28.6% and 28.39%, respectively, which is considered as a very good result. The obtained results showed the feasibility of organic fertilization of soil with compost for winter wheat cultivation.