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The chemical investigation of the methanol root extract of Artocarpus heterophyllus Lam. led to the isolation of a new prenylated flavanone, 5,7,4'-trihydroxy-3'-(3-methylbuta-1,3-dienyl)-5'-(3-methylbut-2-enyl)flavanone, trivially named maghamesin ( 1 ), together with nine known compounds, 5-hydroxy-3',4',5',7-tetramethoxy-8-prenylflavanone ( 2 ), cycloheterophyllin ( 3 ), cyclomorusin ( 4 ), isobavachalcone ( 5 ), trans -isoferulic acid ( 6 ), 24-methylenecycloartan-3α-ol ( 7 ), stigmasterol ( 8 ), β -sitosterol ( 9 ) and β -sitosterol-3- O - β -D-glucopyranoside ( 10 ). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. The absolute configuration of 1 was deduced by comparison of its experimental CD with that of a reported similar compound. Compounds 1-3 and 6-7 were tested for their antibacterial and antifungal activities. Compound 1 displayed a significant antibacterial activity against Staphylococcus aureus with MIC value of 15.625  μ g/mL. The others tested compounds showed moderate antibacterial and antifungal activities against several microorganisms with MIC values of either 31.25 or 62.5 μg/mL.

The stem bark of Ancistrocarpus densispinosus Oliv. exhibited triterpenoids, including the rare fernane-type, fern-9(11)-ene-2α,3β-diol ( 1 ) a possible chemotaxonomically distinct biomolecule for the genus. Other triterpenoids that were isolated from this plant include the ursane-type ursolic acid ( 2 ) and corosolic acid ( 3 ), friedelane-type friedelin ( 4 ) and canophyllol ( 5 ), lupane-type lupeol ( 6 ), betulin ( 7 ), betulinic acid ( 8 ) and hennadiol ( 9 ), oleanoic acid ( 10 ), maslinic acid ( 11 ) and taraxerol ( 12 ) and three sterols. This is the first report of the chemistry of a plant of the Ancistrocarpus . The structures of the compounds were elucidated based on their NMR, IR and MS techniques and by comparisons of their experimental data with those reported. The twelve triterpenoids 1 - 12 were found to be inactive against five bacterial strains Escherichia coli, Bacillus subtilis, Pseudomonas agarici, Micrococcus luteus and Staphylococcus warneri; inactive against KB-3-1 cervix carcinoma cancer cell line and inactive as antioxidants in the DPPH assay.

The phytochemical investigation of the methanolic extracts of roots, stem bark, leaves and twigs of Manilkara obovata has led to the isolation of one new friedelane triterpene, lacefriedelic acid or 3 β ,23-dihydroxy D:A-friedooleanan-28-oic acid ( 1 ) and one new prenylated xanthone, lacexanthone or 4,7-dihydroxy-2,3,3,9,9-pentamethyl-2,2-dihydrofurano[2,3-a]pyrano[2,3-i]xanthen-13( 9H )-one ( 2 ) alongside twenty-four known compounds. Compounds 1 - 11 are reported here for the first time from the genus Manilkara . The structures of all compounds were determined by spectroscopic analyses and X-ray crystallography. The methanolic extracts of twigs and leaves showed anti-oxidant activity of 93.2 and 91.1%, respectively, at 100 µg/mL when measured by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), while the twig extract displayed 86.3% at 100 µg/mL against the urease inhibition assay. Some isolated compounds ( 1 - 4 , 15 and 20 ) showed significant to moderate anti-oxidant activity and urease inhibition assay. It is estimated that significantly active anti-oxidants and urease inhibitors metabolized by the plant may find future application in food industry.

We report the chemistry and biological activities of a Cameroonian Citrus clementina Hort. Ex Tanaka, a vegetatively propagated species. The compounds isolated from this plant were determined to be the known 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone ( 1 ), tangerine ( 3 ), nobilletin ( 4 ), 5,7,8,4'-tetramethoxyflavone ( 5 ), citracridone I ( 6 ), 5-hydroxynoracronycine ( 7 ), citracridone III ( 8 ), xanthyletin ( 10 ), suberosin ( 9 ), E -suberenol ( 11 ), E -methoxysuberenol ( 13 ), 6-formylumbelliferone ( 12 ), aurantiamide acetate ( 2 ), limonin ( 14 ), stigmasterol, β -sitosterol and β -sitosterol-3- O - β -D-glucoside. The structures of the compounds were established on the basis of their NMR spectroscopic data and comparison with published data. Methanol leaf extract and compounds 1 , 2 , 4 , 6 , 7 and 10 were evaluated for their anti-inflammatory, antioxidant, urease and anti-diabetic effects. Compound 10 showed antioxidant activity, anti-inflammatory effect, urease activity and anti-diabetic activity with IC 50 values of 47.3 µM, 33.5 µM, 25.2 µM and 33.9 µM respectively, values that were comparable to the respective positive standards.

A rotameric tryptamide alkaloid (1a-1b) was isolated from the methanolic extract of the roots of Vepris lecomteana together with the known compounds anhydroevoxine (2), lecomtequinoline C (3), evoxine (4), N-methylflindersine (5), evoxanthine (6), hesperidin, lupeol, β-sitosterol and stigmasterol. The previously not reported 7-(3-anilino-2-hydroxyprenyloxy)-8-methoxydictamine (2a) was obtained by opening the epoxide of anhydroevoxine (2). The structures of above compounds were determined by comprehensive spectroscopic analyses of 1D and 2D NMR, EI-/ESI-MS, X-ray crystallography and comparison with the reported data. At room temperature, 1 H and 13 C NMR spectra show two rotamers (1a and 1b) with integrated intensities of 2/3, whereas at around 60 °C, only the 1b conformer was observed. Furthermore, the crystal structure of 1 was determined by the direct method of single crystal X-ray diffraction. The suggested biosynthesis for the formation of the new rotameric tryptamide alkaloid 1 is presented. Some of the isolated compounds (1, 2 and 2a) were tested in vitro against bacteria, resulting in weak for (1 and 2) to moderate activity for (2a) against Micrococcus luteus and Escherichia coli with MIC values of 15.3 and 15.3 μg/mL, respectively., (Copyright © 2019. Published by Elsevier B.V.)