Polyprenylated xanthones with potential anti-inflammatory and anti-HIV effects from the stems and leaves of Cratoxylum cochinchinense (Lour.) Blume.

A phytochemical study on the stems and leaves of Cratoxylum cochinchinense (Lour.) Blume resulted in the isolation and characterisation of a new polyprenylated xanthone, cratocochinone (1), as well as seven known analogues, fuscaxanthone K (2), pruniflorone Q (3), 1,3,5,8-tetrahy-droxy- 2-(3-methybut-2-enyl)-4-(3,7-dimethylocta-2,6-dienyl) xanthone (4), cochinensoxanthone (5), cratoxylum-xanthone B (6), cochinchinone I (7) and cochinchinone K (8). The chemical structure of 1 was determined by comprehensive spectral analyses. The known compounds 2 - 8 were identified by comparing their experimental spectroscopic data with those reported data in the literature. The anti-inflammatory and anti-HIV effects of all isolates 1-8 were evaluated. As a result, compounds 1-8 showed remarkable inhibitory effects against nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells showing IC50 values ranging from 0.68 ± 0.06 to 10.27 ± 0.18 µM. Meanwhile, compounds 1-8 displayed notable anti-HIV-1 reverse transcriptase (RT) effects with EC50 values ranging from 0.19 to 10.72 µM.

Prenylated coumarins from the fruits of Artocarpus heterophyllus with their potential anti-inflammatory and anti-HIV activities.

A phytochemical investigation on the fruits of Artocarpus heterophyllus led to the isolation and characterisation of a new prenylated coumarin, artoheteronin (1), together with six known analogues (2-7). The chemical structure of 1 was elucidated using extensive spectral methods and the known compounds (2-7) were identified by comparing their spectral data with those reported in the literature. All known compounds (2-7) were isolated from the genus Artocarpus for the first time. The anti-inflammatory and anti-HIV activities of all isolated prenylated coumarins (1-7) were assessed in vitro. As a result, compounds 1-7 displayed notable inhibitory effects against nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with the IC50 values in range of 0.58 ± 0.06 to 6.29 ± 0.12 µM. Meanwhile, compounds 1-7 exhibited notable anti-HIV-1 reverse transcriptase (RT) activities possessing EC50 values in the range of 0.18 to 9.12 µM.

Prenylated Chromones from the Fruits of Artocarpus heterophyllus and Their Potential Anti-HIV-1 Activities.

Artocarpus heterophyllus (jack tree) is an evergreen fruit tree belonging to the genus Artocarpus (Moraceae), which is widely distributed in subtropical and tropical regions of Asia. Its fruits (jackfruit), well-known as the world's largest tree-borne fruit, are being consumed in our daily diets as a very popular tropical fruit throughout the world and have been confirmed to hold various health benefits. In this study, five new prenylated chromones, artocarheterones A-E (1-5), as well as seven known prenylated chromones (6-12) were purified and isolated from the ripe fruits of A. heterophyllus (jackfruit). Their chemical structures were determined through comprehensive spectroscopic methods. This is the first report on prenylated chromones isolated from A. heterophyllus. The anti-HIV-1 effects of all isolated chromones were assessed in vitro. As a result, prenylated chromones (1-12) showed remarkable anti-HIV-1 effects with EC50 values ranging from 0.09 to 9.72 µM. These research results indicate that the isolation and characterization of these prenylated chromones with remarkable anti-HIV-1 activities from the ripe fruits of A. heterophyllus could be significant to the discovery and development of new anti-HIV-1 drugs.

Anti-HIV-1 activities of constituents from the rhizomes of Boesenbergia thorelii.

A new lignan, thoreliin A (1), and a new bisnorlignan, thoreliin B (2), were isolated from a MeOH extract of the rhizomes of Boesenbergia thorelii. In addition, the known bisnorlignans 3 and 4, neolignan 5, phenylpropanoids 6-15, as well as benzenoids 18-21 were also obtained from the same source. The structures were elucidated based on their spectroscopic data. By single crystal X-ray analysis, the relative stereochemistry of 1 was confirmed. All isolated compounds were evaluated for anti-HIV-1 activities. Among them, thoreliin A (1) exhibited anti-HIV-1 activities on both HIV-1 reverse transcriptase (41.43% inhibition at 200 µg/mL) and syncytium reduction assays (EC50 20.6 µM, SI 3.7), while compounds 3-6, 9 and 11-21 showed anti-HIV-1 activity only in the anti-syncytium assay (EC50 6.6-454.1 µM, SI >1.32-7.75).

Bioactive monoterpene indole alkaloids from Nauclea officinalis.

Two new monoterpene indole alkaloids, naucleaoffines A (1) and B (2), together with six known alkaloids (3-8), were isolated from the stems and leaves of Nauclea officinalis. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. All isolated compounds were evaluated for their anti-inflammatory activities and anti-HIV-1 activities. Compounds 1-8 exhibited significant inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC50 values comparable to that of hydrocortisone. In addition, compounds 1-8 showed significant anti-HIV-1 activities with EC50 ranged from 0.06 to 2.08 µM. These findings suggest that the discoveries of these indole alkaloids with significant anti-inflammatory activities and anti-HIV-1 activities isolated from N. officinalis could be of great importance to the development of new anti-inflammatory and anti-HIV agents.

Novel tetrahydrofuran derivatives from Trigonostemon howii with their potential anti-HIV-1 activities.

A novel tetrahydrofuran derivative, trigonohowine (1), together with five known tetrahydrofuran derivatives (2-6), were isolated from the stems and leaves of Trigonostemon howii. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. Among them, trigonohowine (1) represents the first example of a new type of tetrahydrofuran derivative, possessing an unprecedented carbon skeleton containing 23 carbon atoms on the carbon skeleton and the known compouds (2-6) are rare tetrahydrofuran derivatives in the plant kingdom with various carbon skeletons. All isolated compounds were evaluated for their anti-HIV-1 activities. Compounds 1-6 showed significant anti-HIV-1 activities with EC50 ranged from 0.08 to 1.03 µM. These findings suggest that the discoveries of these tetrahydrofuran derivatives with significant anti-HIV-1 activities isolated from T. howii could be of great importance to the development of new anti-HIV agents.

Hyperascyrones A-H, polyprenylated spirocyclic acylphloroglucinol derivatives from Hypericum ascyron Linn.

Eight polyprenylated spirocyclic acylphloroglucinol derivatives (PSAPs), hyperascyrones A-H, were isolated from the aerial parts of Hypericum ascyron Linn., together with six known analogs. Their structures were established by spectroscopic analyses including HRESIMS, 1D and 2D NMR, and their absolute configurations were determined by electronic circular dichroism calculations (ECD, Gaussian 09). Structures of previously reported tomoeones C, D, G, and H were revised. Hyperascyrones A-H were evaluated for their cytotoxic and anti-HIV-1 activities, with hyperascyrones C and G exhibiting significant cytotoxicities against HL-60 cell lines with IC50 values of 4.22 and 8.36 µM, respectively. In addition, the chemotaxonomic significance of these compounds was also discussed.