Synthesis, characterization, and biological evaluation of novel cinnamic acid derivatives: cinnamoyl-metronidazole ester and cinnamoyl-memantine amide.

In this study, two derivatives, namely the ester derivative cinnamoyl metronidazole and the amide derivative cinnamoyl memantine, were synthesized from cinnamic acid and respective drugs for the purpose of exploring their potential as novel and efficient antimicrobial agents in the quest of prevailing the global antimicrobial resistance challenge. The synthesis process involved two steps: first, the chlorination of cinnamic acid using thionyl chloride, and second, the esterification of metronidazole or the amidation of memantine. These steps resulted in the formation of cinnamoyl metronidazole/memantine. Optimal reaction conditions were established, and chromatographic techniques were used to separate the synthesized compounds. Confirmation of successful synthesis was achieved through FT-IR analysis, which readily distinguished the chlorinated product and derivatives based on distinctive bands, including mainly the one of carbonyl group. Additionally, molecular structures were validated using 1H NMR and 13C NMR, with all peaks further confirming the successful esterification/amidation of cinnamoyl and drug moieties. Upon evaluating the biological activity, the parent compounds exhibited negligible effects within the tested concentration range. However, the derivatives demonstrated significant activity. The ester derivative exhibited potent activity against the Gram-positive bacterium Staphylococcus aureus, as evidenced by a zone of inhibition measuring 12-15 mm in diameter. Conversely, the amide derivative displayed appreciable biological activity against Candida fungi, with an inhibition zone measuring 11-14 mm.

Antileishmanial polyphenols from Garcinia vieillardii.

Seven xanthones, the new vieillardiixanthones B and C (1) and (7), pancixanthones A (2), B (3), 1,6-dihydroxyxanthone (6), pyranojacareubin and 5,6-O-dimethyl-2-deprenylrheediaxanthone together with two benzophenones, clusiachromene (4) and 3-geranyl-2,4,6-trihydroxybenzophenone (5) were isolated from the stem bark of the neocaledonian Garcinia vieillardii. 2, 5 and 6 showed a significant antileishmanial activity against the promastigote forms of Leishmania mexicana and L. infantum and against the amastigote forms of L. infantum.

New cytotoxic guttiferone analogues from Garcinia virgata from New Caledonia.

There are thirteen endemic species belonging to the genus Garcinia in New Caledonia. Among them, G. virgata is an evergreen tree mainly growing in the rain forests of this island. Fractionation of the cyclohexane extract of the stem bark of this plant produced the known benzophenones guttiferone E and xanthochymol, together with two new guttiferone analogues, namely guttiferones I and J. The structures of these benzophenones were mainly elucidated using 1D and 2D NMR spectroscopy. Compounds and were weakly cytotoxic on the KB cell line with IC50 values of 4.70 and 5.0 microg/mL respectively.

Prenylated xanthones and tocotrienols from Garcinia virgata.

Two xanthones, namely virgataxanthone A and B, have been isolated from the stem bark of Garcinia virgata, together with two formylated tocotrienols and the known delta-tocotrienol, griffipavixanthone and 2,6-dihydroxy-4-methoxybenzophenone (cotoin). Their structures were mainly established using one and two-dimensional NMR and mass spectroscopies. When sufficient material was available, the antioxidant activities of the crude extracts as well as the isolated compounds were evaluated.

Synthesis and in vitro antitumor activity of an isomer of the marine pyridoacridine alkaloid ascididemin and related compounds.

The isomer (9H-quino[4,3,2-de][1,7]phenanthroline-9-one) (2) of the marine alkaloid ascididemin (9H-quino[4,3,2-de][1,10]phenanthroline-9-one) (1) has been synthesized in six steps from 1,4-dimethoxyacridine (10) with an overall yield of 12%. Different related compounds were prepared and tested in vitro at six different concentrations on 12 different human cancer cell lines of various histopathological types (glioblastomas and breast, colon, lung, prostate and bladder cancers). Almost all the compounds present cytotoxic activity of micromolar order.