An MS guided fractionation of the alkaloidal constituents of Flueggea virosa has yielded nine new Securinega alkaloid oligomers, fluevirosinines B-J (1-9). The absolute structures of these oligomers have been characterized on the basis of spectroscopic data and biogenetic consideration. Fluevirosinines B-E (1-4) are four tetramers with new connecting sequences or new oligomerizing patterns, and fluevirosinines G-J (6-9) represent the first examples of pentamers of the Securinega alkaloid family. Among these alkaloids, fluevirosinine B (1) showed the best anti-HIV activity with an EC50 value of 14.1 +/- 1.2 (C) 2014 Elsevier Ltd. All rights reserved.