Chemistry Journal of Moldova

DOI: https://doi.org/10.19261/cjm.2021.848

 

Abstract (PDF)
Graphical Abstract: This study was aimed to investigate the chemica l compositions and lipoxygenase inhibitory activity of the essential oil from Alstonia angustiloba growing in Malaysia. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography and gas chromatography-mass spectrometry. Analysis of the A. angustiloba essential oil resulted in the identification of twenty-five chemical components, attributed 90.8% of the total oil. The most abundant components of A. angustiloba oil were linalool (21.2%), 1,8-cineole (16.8%), α-terpineol (9.5%), terpinene-4-ol (8.5%), β-caryophyllene (6.2%), and caryophyllene oxide (5.2%). The essential oil displayed moderate activity towards lipoxygenase activity with IC₅₀ value of 45.8 μg/mL. 



 

DOI: https://doi.org/10.19261/cjm.2021.856

 

Abstract (PDF)
Graphical Abstract: The purpose of this paper is to put forward concisely some of the most valuable scientific contributions of academician Pavel Vlad and his disciples to the field of natural product chemistry of terpenoids. Under the guidance and with direct contribution of academician Pavel Vlad, new approaches to determining the absolute configuration of a series of labdanic diterpenoids and of converting them into bi-, tri- and tetra- cyclic compounds have been designed. Novel universal methods for synthesizing tetrahydrofurans from 1,4-glycols, olefins from tertiary alcoholic acetates, as well as dienones by means of photodehydrogenation of unsaturated cyclic ketons have been developed by academician Pavel Vlad.

DOI: https://doi.org/10.19261/cjm.2021.841

Abstract (PDF) 

Graphical Abstract: The work was aimed at studying the phytochemicals available in D. antarctica plants from various sites on Antarctic Islands, introducing the plants into in vitro culture and comparing the extracts from the plants grown in situ and in vitro. All the extracts were found to contain high amount of phenols, with luteolin and hydroxybenzoic acids derivatives being the main phytochemicals in the extracts from the plants grown in situ and in vitro. Being diluted by 10 times, the extracts scavenged 50÷90% of DPPH• radicals, 20÷40% of NO• radicals and 40÷60% of OH• radicals. Despite the differences in composition, extracts from the plants grown in situ and in vitro showed similar radical scavenging activity.


 

DOI: https://doi.org/10.19261/cjm.2021.836

 

Abstract (PDF)
Graphical Abstract: (+)-Larixol is a well-known labdane-type diterpenoid widely used in organic synthesis. The present review covers the (+)-larixol based chemical transformations, the results of phytochemical analysis of new (+)-larixol containing species, as well as recent data on biological activity of (+)-larixol and practical applications where it is mentioned.


 

DOI: https://doi.org/10.19261/cjm.2021.820

Abstract (PDF)
Supplementary Material (PDF)

Graphical Abstract: The selective one-step synthesis of 13-epi-manoyl oxide is reported based on a low-temperature superacidic cyclization of sclareol. The reaction conditions have been finely tuned in order to achieve a 9:1 ratio between epimeric oxides in favor of the desired 13-epi-oxide.


 

DOI: https://doi.org/10.19261/cjm.2020.778

Abstract (PDF)
Supplementary Material (PDF)

Graphical Abstract: The present work focuses on evaluation of the chemical composition and antioxidant activity of the hydro-methanolic extract of Melissa officinalis from Algeria. The liquid chromatography-mass spectrometry analysis allowed the identification of six compounds: caffeic acid, caftaric acid, hydroxyjasmonic acid glucoside, caftaric acid glucoside, rosmarinic acid and sagerinic acid. The in-vitro antioxidant activity of the hydro-methanolic extract was evaluated by using four different methods including: radical scavenging assay (DPPH), scavenging activity (ABTS), cupric reducing antioxidant capacity, and ferric reducing power assay.  The extract exhibited a relatively strong antioxidant activity compared to the synthetic antioxidants. The highest radical scavenging activity was registered using DPPH and ABTS methods,  IC₅₀= 20.53±2.64 μg/mL and 22.50±0.67 μg/mL, respectively. These results suggest that Melissa officinalis L. could be considered a potential source of natural antioxidants with potential interest in the agrochemical and pharmaceutical industries.


 

DOI: https://doi.org/10.19261/cjm.2020.791

Abstract (PDF)
Graphical Abstract: The present paper reports the results of microwave irradiation assisted method for the preparation of bicyclohomofarnesenic methyl esters versus classical Stoll and Hinder method. Moreover, the chemical transformations of bicyclohomofarnesenic methyl esters via anodic electrooxidation and dye-sensitized photooxidation were performed. A new method for the preparation of methyl 7-oxo-13,14,15,16-tetranorlabd-6,8(8)-dien-12-oate and the mechanism of electrochemical products formation are presented. The structure of all synthesized compounds was fully confirmed by spectral methods.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.637   

 

Abstract (PDF)
Graphical Abstract: This paper focuses on the study of the effect of extraction solvent choice on phenolic compounds contents and antioxidant activity of Bassia muricata. In this study, five different solvents namely: water, acetone, ethanol, methanol and hexane, and three extraction techniques were used to extract phenolic compounds: microwave-assisted extraction, Soxhlet and maceration. Total phenolics, total flavonoids and condensed tannins contents were determined. The results showed that different solvents with different polarity had a major effect on polyphenolic contents and antioxidant activity. Microwave-assisted extraction was the best suited for the extraction of antioxidant molecules when compared to Soxhlet and maceration.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.609   

 

Abstract (PDF)
Graphical Abstract: TThe present paper reports the synthesis of new hybrid terpeno-heterocyclic compounds belonging to di- and tri-norlabdane series. Starting from natural labdane diterpenoide (-)-sclareol, via its intermediates 8α-hydroxy-15,16-dinorlabd-13-one and sclareolide, two di-norlabdane and three tri-norlabdane, previously unreported compounds possessing 2-amino-1,3-thiazole structural units were obtained in three and four steps, respectively, with acceptable to good overall yields. The structures of newly obtained compounds were confirmed by means of spectral IR, ¹H and ¹³C NMR analyses.


 

 

DOI: http://dx.doi.org/10.19261/cjm.2019.617   

 

Abstract (PDF)
Graphical Abstract: Heterobranchs are a fascinating group of marine mollusks that are recognized as an important source of bioactive natural products. Often, these molecules, which are either selected from the diet or de novo biosynthesized by the mollusks, play a fundamental role for their survival being utilized as defensive chemicals against predators. A summary of the studies carried out, in the last decade, on heterobranchs is presented here. A number of new compounds exhibiting different molecular architectures were chemically characterized.