Symphonin: A new prenylated pyranoxanthone With antimicrobial activity from the seeds of Symphonia globulifera (guttiferae)

A new prenylated pyranoxanthone, symphonin (1), 2-(3,3-dimethylallyl)-1,5- dihydroxy-6,7-dimethoxy-2”,2”-dimethylpyrano (5”,6”:3,4) xanthone, the known compounds guttiferone A, oleanolic acid and  sitosterol  were isolated from the methanol extract of the seeds of Symphonia globulifera (Guttiferae). The structural elucidation of the new compound was based mainly on spectroscopic analyses. The new xanthone showed antimicrobial activity against Staphylococcus aureus, Streptococcus feacalis, Klebsiella pneumonia and Escherichia coli. KEY WORDS: Symphonia globulifera, Seeds, Xanthone, Antimicrobial activity  Bull. Chem. Soc. Ethiop. 2004, 18(2), 175-180

Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae)

Waleguele CC, Mba’ning BM, Awantu AF, et al. Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae). Molecules. 2020;25(12): 2862.The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM

Antiplasmodial Properties and Cytotoxicity of Endophytic Fungi from Symphonia globulifera (Clusiaceae)

Ateba JET, Toghueo RMK, Awantu AF, et al. Antiplasmodial Properties and Cytotoxicity of Endophytic Fungi from Symphonia globulifera (Clusiaceae). JOURNAL OF FUNGI. 2018;4(2): UNSP 70.There is continuing need for new and improved drugs to tackle malaria, which remains a major public health problem, especially in tropical and subtropical regions of the world. Natural products represent credible sources of new antiplasmodial agents for antimalarial drug development. Endophytes that widely colonize healthy tissues of plants have been shown to synthesize a great variety of secondary metabolites that might possess antiplasmodial benefits. The present study was carried out to evaluate the antiplasmodial potential of extracts from endophytic fungi isolated from Symphonia globulifera against a chloroquine-resistant strain of Plasmodium falciparum (PfINDO). Sixty-one fungal isolates with infection frequency of 67.77% were obtained from the bark of S. globulifera. Twelve selected isolates were classified into six different genera including Fusarium, Paecilomyces, Penicillium, Aspergillus, Mucor, and Bipolaris. Extracts from the 12 isolates were tested against PfINDO, and nine showed good activity (IC50 < 10 mu g.mL(-1)) with three fungi including Paecilomyces lilacinus (IC50 = 0.44 mu g.mL(-1)), Penicillium janthinellum (IC50 = 0.2 mu g.mL(-1)), and Paecilomyces sp. (IC50 = 0.55 mu g.mL(-1)) showing the highest promise. These three isolates were found to be less cytotoxic against the HEK293T cell line with selectivity indices ranging from 24.52 to 70.56. Results from this study indicate that endophytic fungi from Symphonia globulifera are promising sources of hit compounds that might be further investigated as novel drugs against malaria. The chemical investigation of active extracts is ongoing

Compounds from <em>Terminalia mantaly</em> L. (Combretaceae) Stem Bark Exhibit Potent Inhibition against some Pathogenic Yeasts and Enzymes of Metabolic Significance<strong></strong>

Tchuenmogne MAT, Ngouana TK, Gohlke S, et al. Compounds from &lt;em&gt;Terminalia mantaly&lt;/em&gt; L. (Combretaceae) Stem Bark Exhibit Potent Inhibition against some Pathogenic Yeasts and Enzymes of Metabolic Significance&lt;strong&gt;&lt;/strong&gt;. Preprints. 2016.The chemical investigation of the anti-yeast methanol extract from the stem bark of Terminalia mantaly led to the isolation of seven compounds: 3-O-methyl-4-O-&amp;alpha;-rhamnopyranoside ellagic acid (1), 3-O-mehylellagic acid (2), arjungenin or 2,3,19,23-tetrahydroxyolean-12-en-28-o&amp;iuml;c acid (3), arjunglucoside or 2,3,19,23-tetrahydroxyolean-12-en-28-o&amp;iuml;c acid glucopyranoside (4), 2&amp;alpha;,3&amp;alpha;,24-trihydroxyolean-11,13(18)-dien-28-o&amp;iuml;c acid (5), stigmasterol (6), stigmasterol 3-O-&amp;beta;-D-glucopyranoside (7). Their structures were established by means of spectroscopic analysis and comparison with published data. Compounds 1-5 were tested in vitro for activity against three pathogenic yeast isolates, Candida albicans, Candida parapsilosis and Candida krusei. The activity of compounds 1, 2 and 4 were comparable to that of the reference compound fluconazole (MIC values below 32 &amp;micro;g/ml) against the three tested yeast isolates. They were also tested for inhibitory properties against four enzymes of metabolic significance: Glucose-6-Phosphate Deshydrogenase (G6PD), human erythrocyte Carbonic anhydrase I and II (hCA I and hCA II), Glutathione S-transferase (GST). Compound 4 showed highly potent inhibitory property against the four tested enzymes with overall IC50 values below 4 &amp;micro;M and inhibitory constant (Ki) &amp;lt;3 &amp;micro;M.</jats:p

Terpenoid alkaloids of the Buxaceae family with potential biological importance

Devkota KP, Lenta BN, Fokou PA, Sewald N. Terpenoid alkaloids of the Buxaceae family with potential biological importance. NATURAL PRODUCT REPORTS. 2008;25(3):612-630.The plants of the family Buxaceae are widely used in traditional medicine and constitute rich sources of terpenoidal alkaloids. Compounds of this family have been the subject of numerous chemical and pharmacological studies over past decades because of their interesting biological activities such as cholinesterase inhibition, as well as antibacterial and antileishmanial activities. The chemical and biological properties of these alkaloids, including data relevant to straightforward structure determination and information on biosynthesis, are highlighted in this review, with 144 references being cited

Crystal structure of obscurine: a natural product isolated from the stem bark of B. obscura

Lenta BN, Chouna RJ, Neumann B, Stammler H-G, Sewald N. Crystal structure of obscurine: a natural product isolated from the stem bark of B. obscura. Acta Crystallographica. Section E, Crystallographic Communications. 2015;71(Pt 7):o457–o458.The title compound, C24H31NO3 {systematic name: (E)-3-[(1R*,2S*,4aS*,8aR*)-2-(benzo[d][1,3]dioxol-5-yl)-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl]-N-isobutylacrylamide}, is a natural product isolated from the stem bark of B. obscura. It is composed of an octahydronaphthalene ring system substituted with an essentially planar benzodioxole ring system [r.m.s. deviation = 0.012 angstrom] and an extended isobutylacrylamide group. In the crystal, molecules are linked by N-H center dot center dot center dot O hydrogen bonds, forming chains propagating along [100]. The chains are linked by pairs of C-H center dot center dot center dot O hydrogen bonds, involving inversion-related benzodioxole ring systems, forming ribbons lying parallel to (010). There are also CH center dot center dot center dot pi interactions present within the ribbons

Vernoguinamide: A new ceramide and other compounds from the root of Vernonia guineensis Benth. and their chemophenetic significance

Wouamba SCN, Happi Mouthe G, Lenta BN, Sewald N, Kouam SF. Vernoguinamide: A new ceramide and other compounds from the root of Vernonia guineensis Benth. and their chemophenetic significance. BIOCHEMICAL SYSTEMATICS AND ECOLOGY. 2020;88: UNSP 103988.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-3 beta-yl acetate (5), lupeol (6) and betulinic acid (7), six steroids, vernoguinoside A (8), vernoguinoside (9), beta-sitosterol 3-O-beta-D-glucoside (10), stigmasterol 3-O-beta-D-glucoside (11), stigmasterol (12) and beta-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

Crystal structure of obscurine: a natural product isolated from the stem bark of B. obscura

The title compound, C24H31NO3 {systematic name: (E)-3-[(1R*,2S*,4aS*,8aR*)-2-(benzo[d][1,3]dioxol-5-yl)-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl]-N-isobutylacrylamide}, is a natural product isolated from the stem bark of B. obscura. It is composed of an octahydronaphthalene ring system substituted with an essentially planar benzodioxole ring system [r.m.s. deviation = 0.012 Å] and an extended isobutylacrylamide group. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains propagating along [100]. The chains are linked by pairs of C—H...O hydrogen bonds, involving inversion-related benzodioxole ring systems, forming ribbons lying parallel to (010). There are also C—H...π interactions present within the ribbons

Crystal and molecular structure of aflatrem

Lenta BN, Ngatchou J, Kenfack PT, Neumann B, Stammler H-G, Sewald N. Crystal and molecular structure of aflatrem. Acta Crystallographica. Section E, Crystallographic Communications. 2015;71(Pt 11):O867-0868.The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the molecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabicyclo[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabicyclo[3.2.1] oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the molecule exhibits a tilt of 2.02 (1)degrees between its two rings. In the crystal, O-H center dot center dot center dot O hydrogen bonds connect molecules into chains along [010]. Weak N-H center dot center dot center dot pi interactions connect these chains, forming sheets parallel to (10 (1) over bar)