BIOLOGICAL STUDIES ON NITROGEN - CONTAINING COMPOUNDS FROM CAMPYLOSPERMUM OLIVERIANUM AND CAMPYLOSPERMUM SULCATUM (OCHNACEAE)

Objective: Campylospermum oliverianum and C. sulcatum (Ochnaceae) are considered conspecific by some reports. Methods: Following phytochemical analyses on those species, biological tests were carried. Results: Phytotchemical analyses led to the isolation of three known nitrogenous compounds: two cyanoglucosides named dhurrin and menisdaurin and an indole alkaloid, serotobenine. These nitrogen-containing compounds showed potent cytotoxic activities against the microcrustacean Artemia salina (brine shrimp), when two of them exhibited efficient bactericidal effects against a few Gram cocci. This newest co-occurrence of both α- and γ-hydroxynitrile glucosides within the same species suggested another biosynthetic pathway for putative tyrosine-derived non-cyanogenic cyanoglucosides. Conclusion: This study does not recommend an identical chemical profile for the two species, hence they might not be regarded as the same. The biosynthetic pathway of numerous putative tyrosine-derived cyanoglucosides is supported by the isolated compounds from C. sulcatum. The taxonomical value of serotobenine in species of the Campylospermum genus as well as the other one of cyanoglucosides in angiosperms is once more highlighted

A new procyanidin B from Campylospermum zenkeri (Ochnaceae) and antiplasmodial activity of two derivatives of (±)-serotobenine

Phytochemical investigation of the stem bark of Campylospermum zenkeri led to the isolation of five known compounds: (Z,Z)-9,12-octadecadienoic acid (1), serotobenine (2), agathisflavone (3), lophirone A (4) and lophirone F (5), together with a new derivative of procyanidin B, a catechin dimer named zenkerinol (6). Serotobenine (2) is structurally related to decursivine which shows moderate activity against D6 and W2 strains of Plasmodium falciparum. For a better understanding of structure-activity relationships, three new semi-synthetic derivatives of serotobenine (2) have been prepared. These are: serotobenine monopropionate (2a), serotobenine monopivalate (2b) and serotobenine cyclohexyl ether (2c) respectively. Two of them (2a) and (2b), were evaluated for their antiplasmodial activity against P. falciparum 3D7 strain in a parasite lactate-dehydrogenase (pLDH) assay. Compound 2b was more active than compound 2a based on their IC50 values (36.6 and 123 μM, respectively)

Antibacterial and cytotoxic activities of undescribed cassiaric acid and other constituents from Cassia arereh stem barks

Please read abstract in the article.The South African Medical Research Council Self-Initiated Research (SAMRC) and the National Research Foundation Thuthuka.https://www.tandfonline.com/loi/gnpl20hj2023BiochemistryChemistryGeneticsMicrobiology and Plant Patholog

Antiplasmodial and antileishmanial inhibitory activity of triterpenes and steroidal alkaloid from the leaves of Funtumia elastica (Preuss) Stapf (Apocynaceae)

peer reviewedThe phytochemical study of leaves of Funtumia elastica led to the isolation of three undescribed ursane derivatives, funtumic acids A, B and C (1–3), as well as one steroidal alkaloid, elasticine (4) and five other known compounds (5–9). Their structures were elucidated on the basis of NMR, MS, IR, UV spectroscopic data as well as by comparison with the literature. The compound 5-hydroxypyridine-3-carboxamide (9) was isolated for the first time from the Apocynaceae family. All the isolated compounds were evaluated for their antiparasitic effects against 3D7 and Dd2 strains of Plasmodium falciparum and promastigotes of Leishmania donovani (MHOM/SD/62/1S). Compounds 1–4 possessed good in vitro antimalarial activities against CQR Dd2 with IC50 values ranging from 4.68 to 5.36 μg/mL and moderate on CQS 3D7. Only compounds 1 and 2 showed leishmanicidal activities with IC50 values ranging between 10.49 and 13.21 μg/mL. In addition, crude extract exhibited potent antiplasmodial (IC50 0.91 and 3.12 μg/mL) and antileishmanial (IC50 3.32 μg/mL) activities, thus demonstrating their potential synergistic action

Antitubercular evaluation of root extract and isolated phytochemicals from Lophira lanceolata against two resistant strains of Mycobacterium tuberculosis

Context: The roots of Lophira lanceolata Van Tiegh. Ex Keay (Ochnaceae) have numerous medicinal values in the Central African region. Even though the MeOH extract of the roots has shown antimycobacterial activities, the constituents responsible for this inhibitory activity remain unknown.Objective: Phytochemical investigation of the MeOH root extract of L. lanceolata and determination of the antimycobacterial activities of that extract and constituents against the growth of Mycobacterium tuberculosis.Materials and methods: Column chromatography was used to provide bioactive phytoconstituents. Those compounds were elucidated using MS and NMR spectroscopic data. Antimycobacterial screening of the extract (4.882– 5000 µg/mL in DMSO during 24 h at 37 °C) and isolated compounds (0.244–250 µg/mL in DMSO during 24 h at 37 °C) was performed by microplate alamar blue assay (MABA) against two mycobacterial strains.Results: The investigation of L. lanceolata MeOH roots extract provided of mixture of unseparated biflavonoids with a newly described one, dihydrolophirone A (1a) associated to lophirone A (1b). The bioactive compounds that effectively inhibited the growth of M. tuberculosis AC45 were found to be compounds 1 and 2. They exhibited MIC values of 31.25 and 15.75 µg/mL, respectively, and their MIC was found to be 62.5 µg/mL against resistant strain AC83.Discussion and conclusions: It is clearly evident from the results obtained that the mycobacterial activity of L. lanceolata could be related mainly to its steroid and flavonoid contents. Therefore, this study suggests the potential of the above- mentioned classes of compounds as promising candidate agents for developing new anti-tuberculosis drugs

Rauvolfianine, a new antimycobacterial glyceroglycolipid and other constituents from Rauvolfia caffra. Sond (Apocynaceae)

The chemical investigation of the extract of the dried leaves of Rauvolfia caffra (Sond) (synonym Rauvolfia macrophylla) (Apocynaceae) led to isolation of a new glycoside derivative, rauvolfianine (1) as well as six known compounds: oleanolic acid (2), sitosterol-3-O-β-D-glucopyranoside (3), betulinic acid (4), vellosimine (5), sarpagine (6) and D-fructofuranosyl-β-(2→1)-α-D-glucopyranoside (7). Compounds 1, 2, 3, 4 and 7 were evaluated for antitubercular activity. Compounds 1 and 2 were the most active (MIC = 7.8125 and 31.25 μg/mL) towards the Isoniazid resistant strain of Mycobacterium tuberculosis AC45. Their structures and relative stereochemistry were elucidated by spectroscopic methods

In vitro antitubercular activity of extract and constituents from the stem bark of Disthemonanthus benthamianus

A new C-glycosylflavone, apigenin 7-methyl ether 6-C-[β-xylopyranosyl-(1→3)-β- glucopyranoside] named distemonanthoside was isolated from the stem bark of Distemonanthus benthamianus Baill., Fabaceae, along with six known compounds, sitosterol 3-O-β-d-glucopyranoside, 4-methoxygallic acid, syringic acid, quercetin, 6″- O-acetylvitexin, quercetin 3-O-β-d-glucopyranoside. The structures of those compounds and others were determined through spectral analyses. Compounds distemonanthoside, sitosterol 3-O-β-d-glucopyranoside, 4-methoxygallic acid and quercetin were tested against a clinical isolate strain of Mycobacterium tuberculosis AC 45; they exhibited good to moderate antitubercular activities with MIC values ranged from 31.25 to 125μg/ml

Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis

Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-β-D- glucopyranosylsitosterol (5), 3-O-β-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10). Their structures were elucidated using IR, MS, NMR 1D and 2D, 1H and 13C and comparison with literature data. Furthermore, compounds 1, 2, 5, 6, 8, 9 and the crude extract were tested against Mycobacterium tuberculosis. Compounds 1, 2, 8 and 9 displayed moderate to very good activity against resistant strain (codified AC 45) of M. tuberculosis with minimum inhibitory concentrations MICs ranging from 3.90 to 62.5 μg/mL

Spectroscopic properties (FT-IR, NMR and UV) and DFT studies of amodiaquine

Amodiaquine (AQ) was synthesized by a condensation reaction and characterized by experimental FT-IR, 1H and 13C nuclear magnetic resonance (NMR) and UV spectroscopies. In the present work, Density Functional Theory (DFT) calculations.The structural and spectroscopic (FT-IR, 1H and 13C NMR and UV) data of amodiaquine molecule in ground state have been investigated by using Density Functional Theory (DFT). The calculations have been performed at the using B3LYP method with 6–311++G(d,p) and 6–311++G(2d, p) basis sets theory level were performed, first, to confirm its structure, then to explain its reactive nature through its molecular properties such as natural charges, local and global reactivity descriptors or natural bond orbital (NBO). Afterwards, the calculated properties were compared with experimental results. The 1H and 13C NMR chemical shifts were calculated by using the gauge-independent atomic orbital (GIAO) method, while the electronic UV–Vis spectrum is predicted using the time-dependent density functional theory (TD-DFT). Globally, the computerized results showed good agreement close similarity with the experimental values. The molecular properties such as natural charges, local and global reactivity descriptors, molecular electrostatic potential (MEP), natural bond orbital (NBO) of title molecule were calculated insights into the stability, reactivity and reactive sites on the molecule.The calculated energy band gap (ELUMO-EHOMO) value of AQ was found to be 4.09 eV suggesting that it could be considered as a hard molecule with high stability, supported by global reactivity descriptors. Molecular electrostatic potential (MEP) analysis revealed heteroatoms (oxygen and nitrogen) as the most putative nucleophilic sites when hydrogen atoms to which they are linked appear as electrophilic sites. The potential use of amodiaquine as non-linear optical (NLO) material and its thermodynamic indicators have also been assessed

A new procyanidin B from <i>Campylospermum zenkeri</i> (Ochnaceae) and antiplasmodial activity of two derivatives of (±)-serotobenine

<p>Phytochemical investigation of the stem bark of <i>Campylospermum zenkeri</i> led to the isolation of five known compounds: (<i>Z,Z</i>)-9,12-octadecadienoic acid (<b>1),</b> serotobenine (<b>2</b>), agathisflavone (<b>3</b>), lophirone A (<b>4</b>) and lophirone F (<b>5</b>), together with a new derivative of procyanidin B, a catechin dimer named zenkerinol (<b>6</b>). Serotobenine (<b>2</b>) is structurally related to decursivine which shows moderate activity against D6 and W2 strains of <i>Plasmodium falciparum</i>. For a better understanding of structure-activity relationships, three new semi-synthetic derivatives of serotobenine (<b>2</b>) have been prepared. These are: serotobenine monopropionate (<b>2a</b>), serotobenine monopivalate (<b>2b</b>) and serotobenine cyclohexyl ether (<b>2c</b>) respectively. Two of them (<b>2a)</b> and <b>(2b)</b>, were evaluated for their antiplasmodial activity against <i>P. falciparum</i> 3D7 strain in a parasite lactate-dehydrogenase (pLDH) assay. Compound <b>2b</b> was more active than compound <b>2a</b> based on their IC₅₀ values (36.6 and 123 μM, respectively).</p