The producers of essential oils from the Republic of Moldova care about the quality of their products and at the same time, try to capitalize on the waste from processing. The purpose of the present study was to analyze the chemical composition of lavender (Lavanda angustifolia L.) essential oil and some by-products derived from its production (residual water, residual herbs), as well as to assess their “in vitro” antimicrobial activity. The gas chromatography-mass spectrometry analysis of essential oils produced by seven industrial manufacturers led to the identification of 41 constituents that meant 96.80–99.79% of the total. The main constituents are monoterpenes (84.08–92.55%), followed by sesquiterpenes (3.30–13.45%), and some aliphatic compounds (1.42–3.90%). The high-performance liquid chromatography analysis allowed the quantification of known triterpenes, ursolic, and oleanolic acids, in freshly dried lavender plants and in the residual by-products after hydrodistillation of the essential oil. The lavender essential oil showed good antibacterial activity against Bacillus subtilis, Pseudomonas fluorescens, Xanthomonas campestris, Erwinia carotovora at 300 μg/mL concentration, and Erwinia amylovora, Candida utilis at 150 μg/mL concentration, respectively. Lavender plant material but also the residual water and ethanolic extracts from the solid waste residue showed high antimicrobial activity against Aspergillus niger, Alternaria alternata, Penicillium chrysogenum, Bacillus sp., and Pseudomonas aeroginosa strains, at 0.75–6.0 μg/mL, 0.08–0.125 μg/mL, and 0.05–4.0 μg/mL, respectively.
Apple (Malus domestica Borkh.), a popular and widely cultivated fruit world-wide, contains bioactive compounds responsible for their health benefits. Here we report the amounts of some bioactive compounds: two major triterpenes (oleanolic and ursolic acids) and polyphenols (phenolic acids, flavan-3-ols, flavonoids and t-resveratrol), together with bioactive properties of twelve apple cultivars measured by chromatographic and spectrophotometric methods. Significant variations were found comparing the bioactive potential of the investigated cultivars. High contents of phenolic acids were identified in the Montuan, Golden Delicious and Cretesc cultivars, while the most flavonoid dominant was the Richard cultivar. Starkrimson, Jonatan, Beliy Naliv and Richard cultivars present higher antioxidant capacity. Oleanolic acid ranged from 11 to 83 mg/g apple extract, while ursolic acid ranged from 55 to 436 mg/g apple extract, with higher amounts in Richard and Montuan cultivars. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed the discrimination of apple cultivars depending on polyphenolic and triterpene acids composition. Caffeic acid, gallic acid and epicatechin were identified as the main bioactive compounds in Starkrimson, Jonathan, Beliy Naliv and Richard cultivars, while ursolic and oleanolic acids were identified in high amounts in Richard, Montuan, Golden Delicious, Idared and Beliy Naliv apple cultivars. The results obtained in this study will contribute to the understanding of the bioactive composition of apples as well as the importance of their capitalization to obtain value-added products that promote human health.
Herein we report a feasible study concerning the synthesis and the in vitro antimicrobial activity of some new homodrimane sesquiterpenoids with a benzimidazole unit. Based on some homodrimane carboxylic acids, on their acyl chlorides and intermediate monoamides, a series of seven N-homodrimenoyl-2-amino-1,3-benzimidazoles and 2-homodrimenyl-1,3-benzimidazoles was synthesized. The syntheses involved the decarboxylative cyclization and condensation of the said acids or acyl chlorides with o-phenylendiamine and 2-aminobenzimidazole, as well as the p-TsOH-mediated cyclodehydration of the said monoacylamides. The structures of the synthesized compounds have been fully confirmed, including by the X-ray diffraction. Their biological activities were evaluated on five species of fungi (Aspergillus niger, Fusarium solani, Penicillium chrysogenum, P. frequentans, and Alternaria alternata) and two strains of bacteria (Bacillus sp. and Pseudomonas aeruginosa). Compounds 7 and 20 showed higher antifungal (MIC = 0.064 and 0.05 μg/mL) and antibacterial (MIC = 0.05 and 0.032 μg/mL) activities compared to those of the standards: caspofungin (MIC = 0.32 μg/mL) and kanamycin (MIC = 2.0 μg/mL), and compounds 4, 10, 14, and 19 had moderate activities.
Synthesis of novel tetranorlabdane derivatives including hybride with terpeno-(1,2)-diazine units and dimers with an unprecedented carbon skeleton, was performed based on methyl 7-oxo-13,14,15,16-tetranorlabd-8-en-12-oate intermediate. The structures of the synthesized compounds have been fully confirmed, including by X-ray diffraction, and their antifungal and antibacterial activity was tested. A possible mechanistic pathway of the cycloaddition reaction is considered.
Teucrium L. is a widely distributed genus often used for the treatment of digestive disorders and respiratory problems. The aim of the present study was to determine the chemical composition of essential oils and elemental content of the plant species Teucrium polium, Teucrium hircanicum, Teucrium botrys, Teucrium chamaedrys, Teucrium flavum, Teucrium orientale, and Teucrium scordium of Moldovan origin, as well as to evaluate the antimicrobial activity of their extracts. The composition of essential oils was determined using gas chromatography–mass spectrometry (GC–MS), and neutron activation analysis (NAA) was used to assess the elemental composition of plants. Antimicrobial tests were performed in vitro on the Bacillus subtilis, Pseudomonas fluorescens, Xanthomonas campestris, Erwinia amylovora, Erwinia carotovora, and Candida utilis strains using the double-dilution method. GC–MS allowed the identification of 59 components of the analyzed essential oils, and showed that the analyzed species belong to four different chemotypes. Using NAA, 18 major and minor elements, the contents of which fell within the value ranges reported for other medicinal herbs of this genus, were identified. The hydroalcoholic extracts from Teucrium spp. exhibited in vitro antibacterial and antifungal activity at 0.03–0.06% and 0.015–0.03%, respectively. The extracts from Teucrium spp. exhibited high antibacterial and antifungal activity, enabling their application for medical purposes.
The mineral contents of roots, leaves, stalks, and inflorescences of the aromatic plant species Anethum graveolens L., Coriandrum sativum L., Lavandula angustifolia Mill., Levisticum officinale W.D.J. Koch, and Salvia sclarea L. were studied by means of neutron activation analysis. The contents of 36 major and trace elements were determined and biological transfer coefficients were calculated. Among major and minor elements, K with a content in the range of 9230–59,600 mg/kg and Fe in the range of 69–3420 mg/kg were the most abundant elements in the studied plants. The content of the toxicant As ranged between 0.14–0.79 mg/kg; however, in the leaves (1.3 mg/kg) and inflorescences (1.0 mg/kg) of L. angustifolia there was found to be about 1 mg/kg, equal to the guideline maximal level recommended for food by the WHO. By comparing the data to Markert’s Reference Plant, “chemical fingerprints” were identified for each species. High contents of the elements Al, Hf, Se, Sc, Na, Ta, Th were determined in all studied plants. Collocated soil samples from the cultivation field were analyzed to calculate the biological accumulation coefficients for 35 of the elements determined in the plants. Considering the levels of chemical elements, the medicinal herb samples investigated are considered as relatively safe for human consumption.