A new bioactive steroidal ketone from the South China Sea sponge Xestospongia testudinaria.

A new steroidal ketone (1), with an ergosta-22,25-diene side chain, was obtained from the South China Sea marine sponge Xestospongia testudinaria. The structure of 1 was determined on the basis of detailed spectroscopic analysis and by comparison with literature. Compound 1 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC50 value of 4.27 ± 0.55 µM, which is comparable with the positive control oleanolic acid (IC50 = 2.63 ± 0.22 µM).

Hainanerectamines A-C, alkaloids from the Hainan sponge Hyrtios erecta.

Two new indole alkaloids, hainanerectamines A (1) and B (2), and one new ß-carboline alkaloids, hainanerectamines C (4), along with five known related alkaloids (3, 5-8), have been isolated from the Hainan marine sponge Hyrtios erecta. The structures of new compounds 1, 2 and 4 were determined by detailed analysis of their 1D and 2D NMR spectra and by comparison of their spectroscopic data with those of related model compounds. Compounds 2-4 exhibited moderate inhibitory activity against Aurora A, a member of serine/threonine kinase family involving in the regulation of cell division and a new target in cancer treatment, with IC50 values of 24.5, 13.6, and 18.6 µg/mL, respectively.

Mulberrofuran G and isomulberrofuran G from Morus alba L.: anti-hepatitis B virus activity and mass spectrometric fragmentation.

Mulberrofuran G (1) and isomulberrofuran G (2), a pair of isomeric Diels-Alder-type adducts, were isolated from the root bark of Morus alba L. Isomulberrofuran G (2) as a new IIB-type Diels-Alder-type adduct, was elucidated by extensive (1)H, (13)C, and two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectroscopic analyses. A fragmentation study on compounds 1 and 2 was performed by high-resolution electrospray ionization (ESI) multistage tandem mass spectrometry linked with ion-trap (IT) and time-of-flight (TOF) mass analyzers (ESI-MS(n)/IT-TOF) in negative mode, which resulted in obviously different fragmentations. In the MS(2) experiments, the characteristic ions at m/z 451 and 439 could be revealed as their respective diagnostic ions. Mulberrofuran G (1) showed moderate activity, inhibiting hepatitis B virus (HBV) DNA replication with the IC(50) value of 3.99 µM, according to the anti-HBV assay on the HepG 2.2.15 cell line in vitro.

A new sulphated nor-sesquiterpene from mangrove Laguncularia racemosa (L.) Gaertn. F.

A new sulphated nor-sesquiterpene, 3alpha-hydroxysulphonyloxy-5alpha,6alpha-epoxy-megastigmen-9-one (1), and a known sulphated lipid, 5'-(hydroxysulphonyloxy) jasmonic acid (2), have been isolated from the twigs and leaves of mangrove Laguncularia racemosa (L.) Gaertn. F. The structure of the new compound was elucidated on the basis of detailed analysis of spectroscopic data and chemical reaction.

[Studies on chemical constituents from leaves of Isatis indigotica].

OBJECTIVE: To study the chemical constituents of the leaves of Isatis indigotica. METHOD: The leaves of I. indigotica were extracted with 80% ethanol. The EtOH extract was dispersed in H20 and extracted with petroleum, EtOAc and BuOH successively. The EtOAc fraction was isolated and purified by column chromatography on silica gel, Sephadex LH -20 and Rp-8, Rp-18. All the compounds were identified on the basis of spectral analyses (including MS, 1H-NMR, 13 C-NMR) , RESULT: Eleven compounds were isolated from the leaves of I. indigotica, and structures were characterized as 10H-indolo [3, 2-b] quinoline (1), indirubin (2), 4 (3H)-quinazo-linone (3), (E)-3-(3', 5'-dimethoxy-4'-hydroxybenzylidene) -2-indolinone (4), 2, 3-dihydropyrrolo [2, 1-b] quinazolin-9(1H) -one (5) , benzoic acid (6) , o-droxy-benzoic acid (7), ( - ) -lariciresinol (8) , ( + ) -isolariciresinol (9), isovitexin (10), 6-f-D-glucopyranosyldiosmetin (11). CONCLUSION: 1, 4, 5, 8, 9, 11 were obtained from the leaves of I. indigotica for the first time.