Extraction of Bioactive Compounds from Medicinal Plants and Herbs

Human beings have relied on herbs and medicinal plants as sources of food and remedy from time immemorial. Bioactive compounds from plants are currently the subject of much research interest, but their extraction as part of phytochemical and/or biological investigations present specific challenges. Herbalists or scientists have developed many protocols of extraction of bioactive ingredients to ensure the effectiveness and the efficacy of crude drugs that were used to get relief from sickness. With the advent of new leads from plants such as morphine, quinine, taxol, artemisinin, and alkaloids from Voacanga species, a lot of attention is paid to the mode of extraction of active phytochemicals to limit the cost linked to the synthesis and isolation. Thus, the extraction of active compounds from plants needs appropriate extraction methods and techniques that provide bioactive ingredients-rich extracts and fractions. The extraction procedures, therefore, play a critical role in the yield, the nature of phytochemical content, etc. This chapter aims to present, describe, and compare extraction procedures of bioactive compounds from herbs and medicinal plants

Antiplasmodial-guided investigation of Lantana camara (Verbenaceae)

editorial reviewe

Bioguided isolation of antiplasmodial secondary metabolites from Mill. (Lauraceae)

Waleguele CC, Tchuente Tchuenmogne MA, Fotsing Fongang YS, et al. Bioguided isolation of antiplasmodial secondary metabolites from Mill. (Lauraceae). Zeitschrift für Naturforschung C. Accepted.**Abstract** The antiplasmodium assay-guided investigation of the roots, stem bark, and leaves ofPersea americanaMill. led to the isolation of a new fatty alcohol, perseatriol (1), along with six known compounds (2–7). Their structures were elucidated based on the analysis of their NMR and MS data. All crude extracts and fractions exhibited good antiplasmodial activity onPlasmoduim falciparum3D7 with IC50values ranging from 0.76 to 10.5 μg/mL; they also displayed cytotoxicity against HeLa cells with low selectivity indexes (SIs). A preliminaryPlasmodiumlactate dehydrogenase (pLDH) assay was also performed on the isolated compounds. 9,9′-Di-O-feruloyl-5,5′-dimethoxysecoisolariciresinol (4) turned out to be non-toxic and displayed the best activities onP. falciparumwith an IC50value of 0.05 μM, comparable to the reference drug chloroquine with an IC50value of 0.03 μM. Furthermore, besides compound4, this work reports the first isolation of lutein (2) and scopoletin (3) fromP. americana. The crude extracts of roots, stem bark, and leaves ofP. americana, their fractions and compounds completely suppressed the growth ofP. falciparum. The observed activity supports the use ofP. americanain folk medicine for the treatment of malaria

A new cerebroside and bioactive compounds from Celtis adolphi-friderici Engl. (Cannabaceae)

Dongmo Jumeta KJ, Kenou Kagho DU, Terence Ateba JE, et al. A new cerebroside and bioactive compounds from Celtis adolphi-friderici Engl. (Cannabaceae). Biochemical Systematics and Ecology. 2021;94: 104201.A phytochemical investigation of the roots of Celtis adolphi-friderici Engl. led to the isolation of a previously undescribed cerebroside named, eloundemnoside (1), alongside with seventeen known compounds (2–18). Their chemical structures were elucidated based on the analysis of their NMR and MS data. All the compounds were isolated from this specie for the first time, while eight known compounds (4–5, 12–13, 15–18) are obtained from the genus Celtis for the first time. The isolates were screened for their antioxidant, lipoxygenase, urease, and butyrylcholinesterase enzyme inhibitory activities. Compounds 4, 7 and 12 showed good antioxidant activities with IC50 values of 22.2, 29.3, and 13.2 μM, respectively. In addition, azelaic acid (12) showed the best lipoxygenase inhibition (IC50 value of 16.3 μM), while friedelin (2) exhibited the highest inhibition of urease with an IC50 value of 15.3 μM. However, all the compounds tested had moderate butyrylcholinesterase inhibitory properties. The chemophenetic relationship of the isolates and their significance were discussed

Constituents of the Stem Bark of Symphonia globulifera Linn. f. with Antileishmanial and Antibacterial Activities

Nguengang RT, Tchegnitegni BT, Nono ECN, et al. Constituents of the Stem Bark of Symphonia globulifera Linn. f. with Antileishmanial and Antibacterial Activities. Molecules. 2023;28(6): 2473.The chemical investigation of the n-hexane fraction from the methanol extract of the stem bark of Symphonia globulifera Linn f., which displayed good in vitro activity against Leishmania donovani NR-48822 promastigotes (IC50 43.11 µg/mL), led to the isolation of three previously unreported polyprenylated benzophenones, guttiferone U (1), V (2)/W (3), and a new tocotrienol derivative named globuliferanol (4), along with 11 known compounds (5–15). Their structures were elucidated based on their NMR and MS data. Some isolated compounds were assessed for both their antileishmanial and cytotoxic activities against L. donovani and Vero cells, respectively. Guttiferone K (5) exhibited the best potency (IC50 3.30 μg/mL), but with low selectivity to Vero cells. The n-hexane fraction and some compounds were also assessed in vitro for their antibacterial activity against seven bacterial strains. All the samples exhibited moderate to potent antibacterial activity (MICs ≤ 15.6 µg/mL) against at least one of the tested strains

Bioguided antiplasmodial isolation of six new labdane-type diterpenoids from the stem bark of Croton sylvaticus Hochst. Ex. Krauss

Gouni CD, Fongang YSF, Dize D, et al. Bioguided antiplasmodial isolation of six new labdane-type diterpenoids from the stem bark of Croton sylvaticus Hochst. Ex. Krauss. Phytochemistry Letters. 2024;59:92-100.The CH2Cl2-MeOH (1:1, v/v) extract of Croton sylvaticus stem bark selectively exhibited good antiplasmodial activity during preliminary screening against the multidrug-resistant (Dd2) and chloroquine sensitive (3D7) strains of Plasmodium falciparum with IC50 values of 10.57 and 18.47 μg/mL, respectively. After fractionation, the fractions exhibited moderate to good activity with IC50 values ranging from 4.31 to 25.49 μg/mL. The purification of these fractions led to the isolation of six new labdane-type diterpenoids named sylvacrotonins Asingle bondF (1single bond6), alongside seven known compounds (7single bond13). Their structures were determined based on the analysis of their NMR and MS data. The isolated compounds were assessed in vitro for their antiplasmodial activity against Pf3D7 and PfDd2. The new labdane-type diterpenoids showed moderate antiplasmodial activity against the two P. falciparum strains, with compound 6 being the most active, with IC50 values of 11.26 and 21.80 μg/mL against PfDd2 and Pf3D7, respectively. Cytotoxic assays were performed on African green monkey kidney Vero cells to ensure that the obtained activity was specific to the parasites. Interestingly, all the tested extracts, fractions, and isolated compounds showed acceptable selectivity (SI > 10) against both Plasmodium strains, except fractions CSB-E (SI = 3.93) and CSB-C (SI = 9.22) against Pf3D7. Globally, with resistance indexes (RIs) lower than 1, all the tested samples were found to be more active against multidrug-resistant (PfDd2) than sensitive (Pf3D7) strains. Furthermore, all the isolated compounds exhibited cell cytotoxicity in the normal Vero cell line. The results from this study confirm the use of C. sylvaticus in malaria-endemic countries for its management and suggest that further lead-optimization studies on hit compounds could drive to the identification of potential lead molecules for antimalarial control and eradication