There is a continuing search for materials having desirable fragrance properties. Such materials are sought either to replace costly natural materials or to provide new fragrances or perfume types, which have not heretofore been available. Hence, the objective of this paper is the synthesis and olfactory characterization of new fragrant materials through chemical modification of methyleugenol (ME) molecular framework by introducing Ester functional groups using appropriate standard procedures. ME is a common phenylpropanoid found in many plant species, particularly in spices and medicinal plants. It is used as a flavouring agent in food and as a fragrance in cosmetics. In this research, methyleugenol was modified to obtain esters. The transformations involve the opening of 2-(4-ethyl-3-methoxybenzyl) oxirane (epoxide ring) to yield 3-(3,4-dimethoxyphenyl)propane-1,2-diol (Dihydroxy). 1-(3,4-dimethoxyphenyl)-3-hydroxypropan-2-yl acetate (53.33% yield) derivatives, was synthesized from the Dihydroxy. The results showed that the odour characteristic of 3-(3,4-dimethoxyphenyl)propane-1,2-diol [floral, pungent, Caramel and sweet] compounds, is clearly different from the odours of the 1-(3,4-dimethoxyphenyl)-3-hydroxypropan-2-yl acetate [fresh, pungent, lime-like, sweet]. Our findings show that double bond substitution and functional alterations to methyl eugenol modify the perceived odour of methyl eugenol derivatives. Thus, overall structural alteration increased odour potency.

The phytochemical screening of extracts of Tacca leontopetaloides tubers has afforded the isolation of two novel chalcones, tarkalynins A and B, along with taccalonolide A and its 12-propanoate. The screening of Zanthoxylum zanthoxyloides stem bark yielded taraxerol acetate, dihydrochelerythrin and fagaramide. These compounds were obtained through column and thin-layer chromatography and identified using NMR and LC-HRMS. The compounds were tested against Trypanosoma brucei brucei s427 and its multi-drug-resistant clone B48, against Trypanosoma evansi, Trypanosoma equiperdum and Trypanosoma congolense, and against Leishmania mexicana. Cytotoxicity was tested against the human HEK293 cell line. The highest activities were observed with dihydrochelerythrin and fagaramide against T. b. brucei s427 and B48, T. evansi, and L. mexicana, with EC₅₀ values of 1.37, 2.559, 1.09, and 5.44 µM and 17.8, 10.9, 10.9, and 13.3 µM, respectively. In addition, tarkalynin A and taraxerol acetate displayed promising activity against T. equiperdum (EC₅₀ = 21.4 and 21.3 µM, respectively). None of these compounds showed significant cross-resistance with existing trypanocides (RF ≈ 1; p > 0.05). The compounds displayed low toxicity to human cells, with most exhibiting no growth inhibition at concentrations of 100, or even 300 µM. This report provides further evidence of the potential use of natural products for combating parasitic diseases.

Phytochemical screening of extracts of Tacca leontopetaloides tubers, has afforded the isolation of two novel chalcones, tarkalynins A and B, along with taccalonolide A and its 12-propanoate. Screening of Zanthoxylum zanthoxyloides stem bark yielded taraxerol acetate, dihydrochelerythrin and fagaramide. These compounds were obtained through column and thin-layer chromatography and identified using NMR and LC-HRMS. The compounds were tested against Trypanosoma brucei brucei s427 and its multi-drug-resistant clone B48, against T. evansi, T. equiperdum, T. congolense, and against L. mexicana. Cytotoxicity was tested against the human HEK293 cell line. The highest activities were observed with dihydrochelerythrin and fagaramide against T. b. brucei s427 and B48, T. evansi, and L. mexicana with EC50 values of 0.5, 0.9, 0.4, and 1.9 µg/mL and of 4.4, 2.7, 2.7, and 3.3 µg/mL, respectively. In addition, tarkalynin A and taraxerol acetate displayed promising activity against T. equiperdum (EC50 = 7.1 and 9.98 µg/mL, respectively). None of these compounds showed significant cross-resistance with existing trypanocides (RF ≈ 1; P>0.05). The compounds displayed low toxicity to human cells, with most exhibiting no growth inhibition at concentrations of 100 or 200 µg/mL. This report provides further evidence of the potential of natural products for combating parasitic diseases.