Design and semisynthesis of oleanolic acid derivatives as VEGF inhibitors: Inhibition of VEGF-induced proliferation, angiogenesis, and VEGFR2 activation in HUVECs / 中国天然药物

Angiogenesis inhibitors targeting the VEGF signaling pathway are developed into drugs for the treatment of vaious diseases, such as cancer, rheumatoid arthritis, and age-related macular degeneration. Recent studies have revealed that oleanolic acid (OA), a natural pentacyclic triterpenoid, inhibited the VEGF/VEGFR2 signaling pathway and angiogenesis in HUVECs, which may represent an attractive VEGF inhibitor. In this paper, rational structural modification towards OA was performed in order to improve its inhibitory effects aganist VEGF and anti-angiogenesis potential. As a result, a series of novel OA derivatives, possessing α,β-unsaturated ketone system in ring A and amide functional group at C-28, were prepared and evaluated for cytotoxicity and their ability to inhibit VEGF-induced abnormal proliferation of HUVECs. The results showed that two promising derivatives, OA-1 and OA-16, exhibited no in vitro cytotoxicity against HUVECs but showed more potent inhibitory activity against VEGF-induced proliferation and angiogenesis in HUVECs, compared with OA. The results of Western blot indicated that OA-1 and OA-16 inhibited VEGF-induced VEGFR2 activation. Furthermore, small interfering RNA experiments were performed to confirm that both compounds inhibited VEGF-induced angiogenesis via VEGFR2. Thus, the present study resulted in the discovery of new promising OA-inspired VEGF inhibitors, which can serve as potential lead compounds for the treatment of angiogenesis-related diseases.

Diversity-oriented synthesis of marine sponge derived hyrtioreticulins and their anti-inflammatory activities / 中国天然药物

Diversity-oriented synthesis is aimed to increase the chemical diversity of target natural products for extensive biological activity evaluation. Indole ring is an important functional group in a large number of drugs and other biologically active agents, and indole-containing natural products have been frequently isolated from marine sources in recent years. In this paper, a series of indole-containing marine natural hyrtioreticulin derivatives, including 19 new ones, were designed, synthesized through a key Pictet-Spengler reaction, and evaluated for their inflammation related activity. Compound 13b displayed the most promising activity by inhibiting TNF-α cytokine release with an inhibitory rate of 92% at a concentration of 20 μmol·L-1. A preliminary structure-activity relationship analysis was also discussed. This research may throw light on the discovery of marine indole alkaloid derived anti-inflammatory drug leads.

Chemical constituents of soft coral Sarcophyton glaucum collected from Xisha and their anti-inflammatory activity / 药学学报

The crude Et2O extract of soft coral Sarcophyton glaucum, collected off the Xisha, the South China Sea, were investigated. A new cembrane-type diterpenoid, namely 15-dehydroxy-sarcophytrol D (1), together with twenty-five known compounds, namely ximaoglaucumin C (2), (11S,12S,1E,3E,7E)-11,12-epoxycembra-1,3,7-triene (3), sarcophytol W (4), cembrene (5), sarcophytol B (6), sarcophytol K (7), sarcophytol J (8), pentaene-cembrene (9), sarcophytol E (10), (+)-marasol (11), (2S)-sarcophytoninsarcophytoxide (12), (-)-17-hydroxydeepoxysarcophytoxide (13), (+)-sarcophytoxide (14), 13-acetoxysarcophytoxide (15), bophynin B (16), 16-oxosarcophytoxide E (17), sarcophinone (18), 7α-8β-dihydroxydeepoxysarcophine (19), (+)-sarcophine (20), 14-dehydroxy-sarcophytol L (21), sarcophytol L (22), 13α-hydroxy-sarcophytol L (23), trocheliophol C (24), trocheliophol E (25) and trocheliophol L (26), were isolated and purified by comprehensive chromatography methods of silica gel column, Sephadex LH-20 gel column, TLC, and semi-preparative high-performance liquid chromatography (HPLC). In anti-inflammatory bioassay, compound 4 exhibited inhibitory effects on lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells.

A new briarane-type diterpenoid from the South China Sea gorgonian Junceella fragilis / 药学学报

The chemical constituents of gorgonian Junceella fragilis Ridley, collected from Ximao Island, the South China Sea, were investigated. A new briarane-type diterpenoid, named fragilide Y (1), together with five known compounds (2–6), namely fragilide D (2), cholesterol (3), ergosterol peroxide (4), 2'-deoxythymidine (5) and cis-thyminenol (6), were isolated from the acetone extract of J. fragilis. The structure of the new compound 1 was elucidated by extensive spectroscopic analysis, while the known compounds were identified by comparison with the reported data. In bioassay, none of these compounds displayed obvious anti-inflammatory and cytotoxic effects.

New lobane-type diterpenoids from the Xisha soft coral Sinularia polydactyla / 中国天然药物

Lobane-type diterpenoids are not frequently discovered from marine soft corals. In this paper, three new lobane type diterpenes, 13-methoxyloba-8,10,15(16),17(18)-tetraene (1), 8,10,13(15)Z,16E-lobatetraene (2) and 19-hydroxy-lobatetraene (3), and a new natural compound, 17,18-epoxyloba-16-acetoxy-8,10,13(15)-trien (4), co-occurring with a known related diterpenoid, 18-methoxyloba-8,10,13(15),16(17)-tetraene (5), were isolated from the South China Sea soft coral Sinularia polydactyla. The structures of new compounds were determined by extensive spectroscopic analysis and by comparison with those reported in the literature. In bioassay, all the isolates were inactive on antibacterial, PTP1B inhibitory, and immunological activities. This study increased the chemical diversity of marine diterpenoids.

Antibacterial sorbicillin and diketopiperazines from the endogenous fungus Penicillium sp. GD6 associated Chinese mangrove Bruguiera gymnorrhiza / 中国天然药物

One new sorbicillin derivative, 2-deoxy-sohirnone C (1), one new diketopiperazine alkaloid, 5S-hydroxynorvaline-S-Ile (2), and two naturally occurring diketopiperazines, 3S-hydroxylcyclo(S-Pro-S-Phe) (3) and cyclo(S-Phe-S-Gln) (4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·mL.

Antibacterial sorbicillin and diketopiperazines from the endogenous fungus Penicillium sp. GD6 associated Chinese mangrove Bruguiera gymnorrhiza / 中国天然药物

One new sorbicillin derivative, 2-deoxy-sohirnone C (1), one new diketopiperazine alkaloid, 5S-hydroxynorvaline-S-Ile (2), and two naturally occurring diketopiperazines, 3S-hydroxylcyclo(S-Pro-S-Phe) (3) and cyclo(S-Phe-S-Gln) (4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·mL.

Clavuridins A and B, two new trinor-guaiane sesquiterpenes isolated from the Xisha soft coral Clavularia viridis / 中国天然药物

In the present study, two new trinor-guaiane sesquiterpenes, named clavuridins B (1), and A (2), along with three known sesquiterpenes (3-5), were isolated from the Xisha soft coral Clavularia viridis. Their structures and absolute configurations were determined on the basis of spectroscopic analysis, X-ray diffraction analysis with Cu Kα radiation and by comparison with related model compounds. Compounds 1 and 3-5 were evaluated for their cytotoxic activity.

Further casbane-type diterpenes from the soft coral Sinularia depressa / 中国天然药物

AIM@#To study the minor diterpenes from the soft coral Sinularia depressa@*METHOD@#The chemical constituents were isolated and purified by various chromatographic techniques, and the chemical structures, including absolute configuration, were established on the basis of detailed analysis of spectroscopic data and by literature comparison with the data of related known compounds.@*RESULTS@#A new casbane-type diterpene, 2-epi-10-hydroxydepressin (1), was isolated and identified.@*CONCLUSION@#Compound 1 is a new casbane-type diterpene.

Review on the secondary metabolites from Xestospongia sponges and their bioactivities / 药学学报

The genus Xestospongia is one of the most widespread genera of sponges, containing abundant secondary metatolites with novel structures and potent bioactivities. The main structure types of secondary metatolites found in this genus are alkaloids, quinines, terpens, steroids, lipids, polyketones, etc. These metatolites exhibit a variety of bioactivities, such as cytotoxic, antibacterial and antiviral activities. This paper reviews the progress in the chemistry and pharmacological activities of the second metabolities from sponges of Xestospongia, especially for recent five years, with the aim for further research.