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The liana Urera gravenreuthii Engl. is an endemic plant to Cameroon which was not yet been chemically and pharmacologically investigated so far despite its uses for medical purposes in local folk medicine to treat several illnesses including dysentery, neuralgia and malaria. This study mainly aimed to contribute to providing further information on the chemical composition of the plant and to identify its antiplasmodial compounds which might support its effectiveness against malaria. The purification of the methanolic extract of U. gravenreuthii led to the isolation and characterization of fifteen distinct compounds (1 ‒ 15) which were structurally confirmed using their NMR data. Thirteen compounds (1 ‒ 11, 14 ‒ 15) were evaluated for their antiplasmodial activity against P. falciparum 3D7 and the results showed that the most active were betulinic acid (2) (2.2 ± 0.2 μ M), rutin (9) (2.8 ± 1.4 μ M), quercetin (8) (3.7 ± 1.3 μ M) and lupeol (1) (4.8 ± 0.3 μ M) which displayed a good activity with IC 50 < 5 μ M. Furthermore, the hypotheses on the structure-activity relationship of the tested compounds and the chemotaxonomic significance of the study have been discussed. The results support the identification of the plant as a member of the family Urticaceae, strengthen its use for the management of malaria and qualify it as an important source of good candidates in new antiplasmodial drug development. [Display omitted] • This is the first chemical and biological investigation of Urera gravenreuthii. • Fifteen compounds have been isolated from the methanolic extract. • Betulinic acid (2) and rutin (9) were the most active with IC 50 values of (2.2 ± 0.2 μM) and (2.8 ± 1.4 μM), respectively, against P. falciparum 3D7. • The structure-activity relationship of the isolated compounds has been discussed. • The obtained results classifies the plant as an important source of antiplasmodial leads for new drugs discovery. [ABSTRACT FROM AUTHOR]

Tetrapleura tetraptera is a well-known plant widely used in Cameroon as spices in cooking and in preparations prescribed in folk medicine for the treatment of malaria. The main purpose of this study was to provide relevant chemical and pharmacological insights that can support the effectiveness of T. tetraptera against malaria by identifying the lead compounds that may be responsible for its therapeutic potential. The stem bark and root methanolic crude extracts of this plant displayed a good inhibition of P. falciparum 3D7 with rates of 83.6% and 76.3%, respectively. A total of sixteen distinct compounds (1 ‒ 16) have been isolated during the chemical investigations of the two active crude extracts. Their structures were established with the aid of their NMR data. Thriteen compounds (2 ‒ 9, 11 ‒ 13, 15 and 16) were screened for antiplasmodial activity using P. falciparum 3D7. Results showed that seven tested compounds displayed good activity (IC 50 < 7 μ M) and the most effective were compounds 5, 9, 7, 2 and 6 with IC 50 values of (1.8 ± 0.4 μ M), (1.9 ± 0.8 μ M), (2.1 ± 0.5 μ M), (2.3 ± 0.7 μ M), (2.4 ± 0.6 μ M), respectively. The in silico evaluation of the isolated compounds for their ability to inhibit the P. falciparum dihydroorotate dehydrogenase 5TBO and their ADMET studies revealed that up to fifteen isolated compounds displayed a greater affinity to the binding site of the 5TBO receptor compared to the reference drug chloroquine. More especially, compounds 1, 2, 4, 8 and 14 demonstrated a good drug-likeness. These findings support the use of T. tetraptera for the management of malaria and further qualify it as an important source of good candidates in new antiplasmodial drug development. [Display omitted] • Bioguided fractionation of the active extracts of Tetrapleura tetraptera led to isolation of sixteen compounds. • The crude extracts and thirteen compounds have been evaluated for their antiplasmodial activity against Plasmodium falciparum 3D7 strain. • Six compounds displayed good antiplasmodial activity with IC 50 ranging from 1.9 μ M to 4.4 μ M. • The action mechanism of the more potent compounds, their molecular docking and ADMET study are presented. • The obtained results further support the use of T. tetraptera for the cure of malaria in traditional medicine. [ABSTRACT FROM AUTHOR]

• Isolation of 4 new compounds from the fruits of Gambeya lacourtiana (Sapotaceae). • First report of cerebrosides and ceramide in the genus Gambeya. • Moderate antibacterial activity of lacourtianoside II. • MS/MS fragmentation of compounds 1, 2 and 4 Phytochemical investigation of the fruits of Gambeya lacourtiana led to the isolation of four new compounds, lacourtianol (1) , lacourtianoside I (2) , lacourtianoside II (3) and lacourtianamide (4) together with six known compounds: 3- O -acetylbetulin (5) , 3- O -acetylerythrodiol (6) , β -amyrincaproate (7) , lupeolhexanoate (8) , erythrodiol 3- O -palmitate (9) , and D -mannitol (10). The structures of 1 - 10 were elucidated on the basis of 1D and 2D NMR spectroscopic data, mass spectrometry and by comparison of spectroscopic data with those from the literature. Compounds 1 - 10 were evaluated for their antibacterial activity. Lacourtianoside II (3) exhibited moderate activity against Salmonella typhi CHU, Staphylococcus aureus (ATCC 43300 and ATCC 25923) and Enterobacter cloacae k2 with the same MIC value of 22.3 μM. [ABSTRACT FROM AUTHOR]

• Zenkersterone is described for the first time as natural products. • Absolute configuration as well as X-Ray data of penianthic acid methyl ester are also described for the first time. • We evaluated the antibacterial and cytotoxic activities of the extracts, fractions and compounds. • We reported the chemotaxonomic relevance of the isolated compounds. A phytochemical investigation of the roots and twigs of Penianthus zenkeri Diels led to the identification of twenty four compounds including one previously undescribed C-28 ecdysteroid (1) and previously described phytosteroids (2–5, 20, 22, 23), phenolic compounds (6–8, 12), diterpenoids (9–11), alkaloids (13,14, 18, 19), a dipeptide (15), ursane type triterpenoids (16–17), a carbohydrate (21) and a fatty alcohol (24). Three semi-synthetic derivatives (5b , 5a, 17a) obtained from acetylation and acetonidation of rubrosterone (5), and allylation of ursolic acid (17), respectively, are also reported. The chemical structures of the compounds were determined using 1D and 2D NMR spectral data, mass spectrometry and by comparison with the data reported in the literature. The absolute configuration of compound 9 was established using X-Ray and ECD analysis. Different extracts of the twigs and roots, compounds 2 – 4 , 6 – 11 , 15 , and 17 – 21 were evaluated for their antibacterial, and cytotoxic activities. The twigs extract showed an antibacterial activity with an MIC of 62.5 μg/mol against Staphylococcus aureus ATCC 4300, while ursolic acid exhibited a moderate cytotoxicity with an IC 50 of 50.9 μM. The chemotaxonomic relevance of the isolated compounds is discussed. [ABSTRACT FROM AUTHOR]

• We provide the first review about the plant Harungana madagascariensis. • We summarize the knowledge of phytochemistry and pharmacology of the plant. • We proposed some investigations to complete the broader overview of the plant. This mini review describes the research between 1962 and 2019 on ethnobotany, chemistry and pharmacology of Harungana madagascariensis (Hypericaceae), the unique plant species in the genus Harungana. The plant is mainly distributed in Africa and Europe, where it has been used in the traditional medicine to cure several diseases. The first chemical investigation of H. madagascariensis genus took place earlier in 1962 with the isolation of harunganin whose the structure was characterized by X-ray. Several works have been done over the last 57 years on leaves, bark, roots and branches of the plant and as result, 42 secondary metabolites belonging to numerous classes of compounds including anthranoids, anthraquinones, xanthones, triterpenoids, flavonoids, steroids and alkaloids have been isolated and are presented herein together with some derivatives obtained from chemical transformations including thermal rearrangement and allylation. The anthranoids reported from natural sources represent almost 49 % of the total secondary metabolites obtained from the genus and display the most potent biological activities. Along with anthraquinones, they constitute the chemo markers of Harungana. The extracts and compounds from the plant have been evaluated for their potencies in antimicrobial, anti-protozoan, anti-sickling, anti-inflammatory, antioxidant, enzyme inhibition or cytotoxic activities. The results support the uses of H. madagascariensis in folk medicine and provide further evidence in new drugs discovery. [ABSTRACT FROM AUTHOR]

• We isolated two new naturally occurring compounds named trichirokin (1) and ergosta-5,24(28)-diene-3 S ,16 S ,20 S -triol (4). • We reported for the first time the crystal structures of rohituka-3 (3) and ergosta-5,24(28)-diene-3 S ,16 S ,20 S -triol (4). • The NMR data of ergosta-5,24(28)-diene-3 S ,16 S ,20 S -triol (4) are reported for the first time. • The isolated compounds were tested for their antibacterial and cytotoxic activities. Phytochemical investigation of the stem bark extract of Trichilia emetica led to the isolation of two new naturally occurring compounds including a prieurianin-class limonoid named trichirokin (1) and the steroid ergosta-5,24(28)-diene-3 S ,16 S ,20 S -triol (4), along with nine known compounds characterized as rohituka-3 (3), rohituka-9 (2), scopoletin, benzoic acid, protocatechuic acid, lignoceric acid, β -sitosterol, stigmasterol and β -sitosterol-3- O - β -D-glucopyranoside. The crystal structures of rohituka-3 (3) and ergosta-5,24(28)-diene-3 S ,16 S ,20 S -triol (4) are reported here for the first time. The structures of the compounds were elucidated by extensive spectroscopic and spectrometric data interpretation. The stereochemistry of compound 1 was established on the basis of its NOESY spectrum and the comparison of its optical rotation value with that of its congener 2. None of the reported compounds displayed antibacterial or cytotoxic activity. [ABSTRACT FROM AUTHOR]

Chemical investigation of the roots of Entandrophragma congoënse (Meliaceae) led to the isolation of two new 3,4- seco -tirucallane triterpenes, namely seco -tiaminic acids B and C ( 1 and 2 ) together with nine known compounds: 3,4-secotirucalla-21-formyl-23-oxo-4(28),7,24-trien-3-oic acid ( 3 ), methyl angolensate ( 4 ), molucensin N ( 5 ), molucensin O ( 6 ), piscidinol A ( 7 ), 7 α ,20( S )-dihydroxy-4,24(28)-ergostadien-3-one ( 8 ), 24-methylene-cholest-5-en-3 β ,7 α -diol ( 9 ), entilin A ( 10 ), and entilin B ( 11 ). Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, HRMS, and CD analyses; new results were compared to existing data in the literature. The two newly identified seco -tiaminic acids showed moderate antiplasmodial and cytotoxic activities against a chloroquine-sensitive strain of the malaria parasite ( Plasmodium falciparum NF54) and were cytotoxic toward an L6 rat skeletal myoblast cell line, respectively. [ABSTRACT FROM AUTHOR]

Two new tirucallane-type triterpenoids were isolated from the bark of Entandrophragma congoënse (Meliaceae) along with five known compounds gladoral A, bipendensin, 4-hydroxymethyl-3,5-dimethyldihydrofuran-2(3 H )-one, scopoletin and 5,7-dimethoxy-6-hydroxycoumarin. Their structures were elucidated by means of spectroscopic analyses including 1D and 2D-NMR spectroscopy, high resolution mass spectrometric data as well as the comparison of data with those reported in the literature. The tested compounds ( 1 – 4 ) displayed moderated antiplasmodial activity against erythrocytic stages of chloroquine-resistant Plasmodium falciparum strain NF54 and low cytotoxicity on L6 cell lines. All the isolated compounds are reported for the first time from the genus Entandrophragma. [ABSTRACT FROM AUTHOR]

The triterpenes represent one of the most reported subclasses of specialized metabolites from the plant kingdom. They play a key role in the protection of plants and their metabolism in addition to displaying a high structural diversity and large scale of biological activities. The scaffold can undergo several reactions like oxidation or substitution at different positions of the skeleton leading to the formation of several types of compounds. More specifically, triterpene dimer is a small group of compounds found in nature (from plants precisely). Until 2021, the chemical and pharmacological works reported in the literature indicated the identification of 90 natural dimeric triterpenes and 11 synthetic derivatives from 19 plants species and very few of them have been biologically evaluated for their antibacterial, antioxidant, antiproliferative or molluscicide activities. This review aims to compile the literature on the occurrence, chemistry and biological activities of the triterpenoid dimers. To attend this goal, a literature survey has been done in a number of online libraries including Scifinder, PubMed, Web of Science and Google Scholar using keywords terpene, triterpene, dimer, celastroloid without language restriction. This paper provides the easiest access to the information on triterpene dimers for readers and researchers in view to enhancing the continuity of research works on this topic. [Display omitted] A comprehensive compilation of literature and discussion on the occurrence, chemistry and antibacterial, antioxidant, antiproliferative as well as molluscicide activities of a total of 90 natural occurring triterpene dimers and 11 synthetic analogues reported from 19 plants species until 2021. • Total of 90 naturally dimeric triterpenoids from 19 plant species are reported. • Eleven semi-synthetic triterpene dimers derivatives have been prepared so far. • Celastroloids represent the most abundant triterpene dimers. • Biological activities of the triterpene dimers are discussed. [ABSTRACT FROM AUTHOR]

The phytochemical exploration of the Entandrophragma candollei stem bark extract led to the isolation and identification of twenty compounds including three undescribed phragmalin-class limonoids named encandollens C–E (1 – 3), the undescribed protolimonoid 5 together with sixteen known compounds. The structures of all the isolated compounds were determined by interpretation of their spectroscopic and spectrometric data including HRMS, 1D and 2D NMR analyses. The assignment of the absolute and relative stereochemistry of the undescribed compounds was achieved using SC-XRD analyses as well as NOESY experiments. The previously reported structure of odoratone (5a) was corrected as 23 R,24 S-dihydroxy-22 S,25-epoxytirucall-7-en-3-one (5) based on its NMR and SC-XRD data. Prieurianin (4) exhibited high cytotoxic activity on KB3-1 cell lines with an IC 50 of 1.47 μM compared to the reference griseofulvin (IC 50 = 17–21 μM). The results of the in silico docking of compound 4 supported and delivered further insights on its cytotoxicity. Image 1 • Three undescribed phragmalin-type limonoids encandollens C-E were obtained from Entandrophragma candollei. • The structure of odoratone was corrected as 23 R,24 S-dihydroxy-22 S,25-epoxytirucall-7-en-3-one using its SC-XRD and NMR analyses. • Three previously undescribed hemi-synthetic derivatives odoratonides I-III were obtained from acetonide preparation of odoratone. • We reported the cytotoxicity of prieurianin and its molecular docking studies to enzymes human neutrophil collagenase MMP-8, tubulin and Human DNA topoisomerase I. [ABSTRACT FROM AUTHOR]

• Two new steroids tiamenones A and B were obtained from Entandrophragma angolense. • For the first time a steroid with a 20,24-epoxy-24-hydroxymethyl moiety was isolated. • We reported the molecular docking studies of tiamenones A, B and 20S-hydroxy-4,6,24(28)-ergostatrien-3-one to enzyme pyruvate kinase PKM2. Two new ergostane-type steroids named tiamenones A and B (1 – 2) were isolated from the bark of Entandrophragma angolense (Meliaceae) along with ten known compounds identified as 20 S -hydroxy-4,6,24(28)-ergostatrien-3-one (3), 3 β ,7 α ,20 β -trihydroxyergosta-5,24(28)-diene (4), 3 β ,5 α -dihydroxyergosta-7,22-diene (5), stigmasterol, β -sitosterol, β -amyrin, oleanolic acid, asperphenamate, sucrose and daucosterol. The structures of the isolated compounds have been established using NMR spectroscopic and mass spectrometric analyses. The assignment of relative and absolute configurations of compound 1 was achieved by a NOESY experiment and comparison of its NMR data with those of known compound reported in literature. Compounds 1 – 3 , β -amyrin and asperphenamate were evaluated for their antibacterial potencies against five bacterial model strains viz. Escherichia coli DSMZ 1058, Pseudomonas agarici DSMZ 11810, Bacillus subtilis DSMZ 704, Micrococcus luteus DMSZ 1605 and Staphylococcus warneri DSMZ 20036 and their cytotoxicity on two cell lines KB3-1 and HT-29. No potencies were exhibited by the tested compounds even at the highest concentration of 0.5 mg/mL. Compounds 1 – 3 were found to be potential HIV-1 inhibitors based on their molecular docking analyses. [ABSTRACT FROM AUTHOR]

The chemical investigation of the roots of Vernonia guineensis Benth. (Asteraceae) resulted in the isolation of a new ceramide, named vernoguinamide (1), together with fifteen known compounds, including three anthraquinones, physion (2), erythroglaucin (3) and emodin (4), three triterpenoids, hop-17(21)-en-3β-yl acetate (5), lupeol (6) and betulinic acid (7), six steroids, vernoguinoside A (8), vernoguinoside (9), β -sitosterol 3- O - β -D-glucoside (10), stigmasterol 3- O - β -D-glucoside (11), stigmasterol (12) and β -sitosterol (13) and three fatty acid derivatives, tetracosanoic acid (14), tricosanic acid (15) and arachidic acid glycerol ester (16). The structure of the new compound as well as those of the known compounds were established by spectrometric analysis including HRESI-MS, 1D and 2D-NMR and by comparison with the previously reported data. Among these compounds, the anthraquinones 2 – 4 and the triterpene 5 were isolated for the first time from Vernonia genus and compounds 6 , 7 and 14 – 16 were extracted for the first time from the species. The isolated compounds were tested for their antibacterial activity and 3 , 8 and 9 were the most active compounds against the tested bacteria. Furthermore, the chemophenetic relationships of the isolated compounds and their significance were also discussed. Image 1 • New secondary metabolites in Vernonia guineensis Benth. • Antibacterial compounds from V. guineensis Benth. • Anthraquinones in the genus Vernonia. • Chemophenetic significance of the isolated compounds. [ABSTRACT FROM AUTHOR]