New antimicrobial cyclolignan and others constituents from the leaves of Scyphocephalium mannii (Benth. & Hook.f.) Warb.

Chemical investigation of the MeOH extract of the leaves of Scyphocephalium mannii (Benth. & Hook.f.) Warb. (Myristicaceae) led to the isolation and characterization of one new metabolite (+)-(7'S, 8S, 8'S)-4,4'-dihydroxy-3,3',5,5'-tetramethoxy-2,7'-cyclolignan (1) along with five known compounds. Their structures were elucidated by spectroscopic means, including 1 D and 2 D NMR, HRESI-MS and by comparison with published data. The absolute configuration of compound 1 was determined by single-crystal X-RAY diffraction. Compound 1 showed moderate antifungal activity against Cryptococcus neoformans with respective MIC and MMC values of 64 and 256 µg/mL.

Bioguided identification of pentacyclic triterpenoids as anti-inflammatory bioactive constituents of Ocimum gratissimum extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Ocimum gratissimum is a plant spice widely used in African traditional medicine to treat pain-related conditions. However, the anti-inflammatory mechanisms underlying this activity and the main active ingredients in O. gratissimum have not yet been fully characterized. AIM OF THE STUDY: To isolate and identify the main anti-inflammatory active constituents of Ocimum gratissimum extract and their underlying mechanisms in murine macrophages. MATERIAL AND METHODS: Chromatographic techniques and spectroscopic data were used for compounds isolation and identification. Inflammatory conditions were produced in cultured RAW 264.7 macrophage cells by the application of lipopolysaccharide (LPS). The WST-1 assay was used to evaluate the cell viability, and the nitric oxide production was quantified by the Griess reagent method. The fluorometric cyclooxygenase (COX) activity assay kit was used to assess the activity of COX-1 and COX-2 enzymes. The levels of IFN-γ, TNF-α, IL-2, IL-4, IL-6, and IL-10 cytokines and the apoptosis-inducing effect were measured by flow cytometer using the cytometric Bead Array (CBA) Human Th1/Th2 Cytokine Kit II and FITC Annexin V Apoptosis Detection kit, respectively. RESULTS: The results showed that the extract and fractions of Ocimum gratissimum inhibit nitric oxide production and the proliferation of Raw 264.7 macrophage cells. The bioguided fractionation led to the identification of pentacyclic triterpenes as anti-inflammatory bioactive compounds. Pomolic and tormentic acids being the most active, inhibiting the secretion of IFN-γ cytokine, COX enzyme, and inducing apoptosis in activated Raw 264.7 macrophage cells. CONCLUSIONS: This study revealed that pomolic and tormentic acids are the main active principles responsible at least in part for the anti-inflammatory effect of the extract of Ocimum gratissimum. Besides of providing more evidence for the traditional use of Ocimum gratissimum against inflammatory disorders, this study reveals the multitarget potential of pomolic and tormentic acids as promising future drugs against inflammatory diseases.

Neomacrodione: a new degraded diterpenoid from the roots of Neoboutonia macrocalyx Beng (Euphorbiaceae).

One new degraded diterpenoid 3,6-dihydroxy-1,7-dimethyl-9,10-phenantroquinone (neomacrodione) (1) together seven known compounds were isolated from the roots of Neoboutonia macrocalyx (Euphorbiaceae). The structures of the compounds were established based on their NMR and mass spectrometric data in conjunction with those previously reported in the literature. Compound (1) displayed moderate antibacterial activities.

Induction of new metabolites from the endophytic fungus Bionectria sp. through bacterial co-culture.

A new alkaloid, 1,2-dihydrophenopyrrozin (1), along with five known compounds (2-6) was isolated from an axenic culture of the endophytic fungus, Bionectria sp., obtained from seeds of the tropical plant Raphia taedigera. Co-cultivation of this fungus either with Bacillus subtilis or with Streptomyces lividans resulted in the production of two new o-aminobenzoic acid derivatives, bionectriamines A and B (7 and 8) as well as of two additional known compounds (9 and 10). None of the latter compounds (7-10) were detected in axenic cultures of the fungus or of the bacteria indicating activation of silent biogenetic gene clusters through co-cultivation with bacteria. The structures of the new compounds were unambiguously determined based on detailed NMR and MS spectroscopic analysis and by comparison with the literature. The crystal structure of agathic acid (6) is reported here for the first time. Penicolinate A (4) exhibited potent cytotoxic activity against the human ovarian cancer cell line A2780 with an IC50 value of 4.1µM.

Bioactive chemical constituents of Duboscia macrocarpa Bocq., and X-ray diffraction study of 11ß, 12ß-epoxyfriedours-14-en-3α-ol.

A new γ-lactone triterpenoid, Evodoulolide (1) and a new triterpenoid Duboscic acid B (2), along with five known compounds, maslinic acid (3), arboreic acid (4), (E)-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl) ethyl] prop-2-enamide (5), (E)-heptacos-19-enoic acid (6) and 11ß,12ß-epoxyfriedours-14-en-3α-ol (7) were isolated from the trunk wood of Duboscia macrocarpa. Their structures were elucidated from extensive 1D- and 2D-NMR and MS and by comparison of their spectra with published data. Compounds 1, 3, 5 and 6 exhibited significant α-glucosidase inhibitory activity. Compound 5 was found to be a potent inhibitor (IC50=5.1±0.1µM) of α-glucosidase as compared to acarbose (IC50=625.0±1µM) used as standard drug. These compounds did not show anti-glycation activity using the BSA-MG glycation model or inhibition against the α-chymotrypsin enzyme. The chemotaxonomic connotation of the isolated secondary metabolites is also herein described. The single-crystal X-ray and absolute configuration diffraction analysis of 11α, 12α-epoxyfriedours-14-en-3-ol (7) is also described here for the first time.

Chemical constituents of Stereospermum acuminatissimum and their urease and α-chymotrypsin inhibitions.

Phytochemical investigation of the stem bark of Stereospermum acuminatissimum K. Schum. resulted in the isolation of 21 compounds, including two new guanine derivatives, 1,3,7-trimethylguanin-1/3-ium (1) and 3,7-dimethylguanin-1/3-ium (2), and one new phenolic long chain ester, 2-(4-hydroxyphenyl)ethyl hentriacontanoate (3). The known compounds were identified as sterequinones A, F, and H (4, 5, and 6), zenkequinones A-B (7-8), p-coumaric acid (9), methyl caffeate (10), caffeic acid (11), psilalic acid (12), syringaldehyde (13), norviburtinal (14), specioside (15), verminoside (16), tyrosol (17), eutigoside A (18), ellagic acid (19), atranorin (20), and ursolic acid (21). The metabolites were screened for their potential against urease and α-chymotrypsin enzymes, as urease is targeted in peptic ulcer while α-chymotrypsin is used to remove protein debris in ulcer. Compound 20 was found to be excellent urease inhibitor with IC(50) value of 18.2 ± 0.03 µM. Compounds 13 and 18-20 are reported for the first time from the genus Stereospermum. The chemotaxonomic significance of the isolated compounds was also described.

Canarene: a triterpenoid with a unique carbon skeleton from Canarium schweinfurthii.

Canarene (1), a triterpene with an unprecedented carbon backbone, was isolated from Canarium schweinfurthii . It is the first member of a new class of triterpenoids, for which the name "canarane'' is proposed. 1 showed weak α-glucosidase inhibitory activity, and its structure was unambiguously deduced by single-crystal X-ray diffraction.

Kaurane-type diterpenoids from Chromoleana odorata, their X-ray diffraction studies and potent α-glucosidase inhibition of 16-kauren-19-oic acid.

A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid (1), along with five known metabolites, 16-kauren-19-oic acid (2), 6'-hydroxy-2',3',4,4'-tetramethoxychalcone (3), isosakuranetin (4), acacetin (5), and kaempferide (6) was isolated from the organic extracts of the roots of Chromoleana odorata. Their structures were determined by spectroscopic evidences. The structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction studies. Compound 2 exhibited significant α-glucosidase inhibitory and antibacterial activities against Escherichia coli and Bacillus subtilis.

Duboscic acid: a potent α-glucosidase inhibitor with an unprecedented triterpenoidal carbon skeleton from Duboscia macrocarpa.

Duboscic acid (1), a triterpenoid with a unique carbon backbone, was isolated from Duboscia macrocarpa Bocq. It is the first member of a new class of triterpenoids, for which the name "dubosane" is proposed. Duboscic acid has a potent α-glucosidase inhibition, and its structure was unambiguously deduced by a single-crystal X-ray diffraction study.

Prenylated anthronoid antioxidants from the stem bark of Harungana madagascariensis.

Two new prenylated anthronoids, harunmadagascarins A and B, were isolated from the stem bark of Harungana madagascariensis along with six known compounds including two anthronoids: harunganol B and harungin anthrone, one benzophenone: methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate and three pentacyclic triterpenes: friedelin, lupeol and betulinic acid. Harunmadagascarins A and B were characterized as 8,9-dihydroxy-4,4-bis-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone and 8,9-dihydroxy-4,4,5-tris-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone, respectively. The structures of these secondary metabolites were determined by spectroscopic means and comparison with the published data. Methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate was isolated for the first time from a plant. Harunmadagascarins A and B, harunganol B and harungin anthrone exhibited significant antioxidant activity.