Constituents of Croton megalocarpus with Potential Anti-HIV Activity.

Reported herein is an anti-HIV monochlorinated compound, 1ß-acetoxy-3ß-chloro-5α,6α-dihydroxycrotocascarin L (1), of the rare crotofolane diterpenoid class. Compound 1, a suspected artifact of extraction, along with the previously undescribed 11ß-acetoxycrotocascarin L (2) and a known compound, crotocascarin K (3), were isolated from the bark of Croton megalocarpus, a Kenyan oil-producing seed crop. Compounds 1 and 3 inhibited HIV-1 replication with IC50 values of 28 and 5.5 nM, respectively. Furthermore, both compounds lacked cytotoxicity toward MT-4 cells and FM-55-M1 cells at concentrations of up to 50 µM. Compounds 1 and 3 were both found to inhibit HIV-1 protease.

Terpenes from Zingiber montanum and Their Screening against Multi-Drug Resistant and Methicillin Resistant Staphylococcus aureus.

Bioassay directed isolation of secondary metabolites from the rhizomes of Zingiber montanum (Fam. Zingiberaceae) led to the isolation of mono-, sesqui-, and di-terpenes. The compounds were characterized as (E)-8(17),12-labdadiene-15,16-dial (1), zerumbol (2), zerumbone (3), buddledone A (4), furanodienone (5), germacrone (6), borneol (7), and camphor (8) by analysing one-dimensional (1D) (¹H and 13C) and two-dimensional (2D) (COSY, HSQC, HMBC, and NOESY) NMR data and mass spectra. Among these terpenes, compounds 1 and 2 revealed potential antibacterial activity (minimum inhibitory concentrations (MIC) values 32⁻128 µg/mL; 0.145⁻0.291 mM)) against a series of clinical isolates of multi-drug resistant (MDR) and Methicillin resistant Staphylococcus aureus (MRSA).