Didemnaketals are rare terpenoid class reported only in the marine ascidian Didemnum species. They possess important biological activities like HIV-1 protease inhibitor, protein kinase inhibition, antimicrobial, antiproliferative, and cytotoxic. A compilation of new naturally occurring didemnaketals reported during 1991–2014 is provided with available physical and spectral data: mp,[a]D, UV, IR, 1H and 13C NMR as well as biological activities and references.

As a part of our continuing interest in identifying anticancer drug leads from natural sources, we have investigated the n-BuOH fraction of the root bark of Calotropis procera (Ait) R. Br. Seven new oxypregnane oligoglycosides: calotroposides H–N (1–7) were isolated and identified. Their structures were established on the basis of 1D and 2D NMR studies, HRMS, and GCMS spectral data. The in vitro growth inhibitory activity of the n-BuOH fraction and compounds 1–7 was evaluated against A549 non-small cell lung cancer (NSCLC), U373 glioblastoma (GBM), and PC-3 prostate cancer cell lines. Compounds 4 and 6 showed subnanomolar growth inhibition activity with IC50 ranging from 0.5 to 0.7 lM against U373 glioblastoma (GBM) and PC-3 prostate cancer cell lines. These results provide further insight into the chemical diversity and biological activities of this class of compounds.

Chemical examination of the fungus Aspergillus aegyptiacus isolated from cotton textile yielded two new pyrrolidine alkaloids: aegyptolidine A (3) and aegyptolidine B (4), together with two known ophiobolin sesterterpenoids: ()-5-deoxovariecolin (1) and variculanol (2). Compound 1 is reported for the first time from a natural source. The structures of the isolated compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis (1D (1H and 13C) and 2D (1H–1H COSY, HMQC, HMBC, and NOESY)NMR, MS, IR, and UV) and comparison with literature data. Compounds 1 and 2 showed moderate cytotoxic activity against murine lymphoma cancer cell line L5178Y with ED50 7.6 and 8.1 mg/mL, respectively.

2-(2-Phenylethyl) chromone (PEC), an uncommon class of chromones, possesses a phenylethyl substituent at the C2 position. They have been isolated from a few plant species. They have promising biological activities such as neuro-protective, cytotoxic, cetylcholinesterase inhibitory, antibacterial and anti-inflammatory. This review focuses on the naturally occurring PEC derivatives, their sources, physical and spectral data, as well as biological activities.

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