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.

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

Two new indole alkaloids, hainanerectamines A (1) and B (2), and one new β-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.

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.

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.

[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.