Palicourea tomentosa (Aubl.) Borhidi (Rubiaceae, Palicoureeae), earlier classified as Psychotria poeppigiana Müll. Arg., is used in folk medicine for a variety of diseases. Biological studies on the plant describes their vasorelaxant, antiplasmodial, antitumoural and anticholinesterase activities. To expand the knowledge on the chemical and biological potential of this species, in this work, phytochemical and dereplication studies, as well as antimicrobial and anticholinesterase evaluation of Palicourea tomentosa were carried out. Phytochemical investigation deals with the isolation of lutein (1), a mixture of dehydrovomifoliol (2) and megastigma-4,7-dien-3-one (3), loliolide (4), 5,13-epoxy-9-hydroxy-megastigma-7-en,3-one (5), vomifoliol (6), asperuloside (7), 3-O-p-coumaroylquinic acid (8), and a mixture of the pyrrolizidinoindoline alkaloids hodgkinsine (9), chimonanthine (10) and psychotriasine (11). The ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC HRMS/MS) based on molecular networking dereplication of dichloromethane fraction led to putative identification of other two megastigmanes, one terpene lactone and three carotenoids, besides seven triterpenes and four indole alkaloids. The dichloromethane, ethyl acetate and hydromethanol fractions of P. tomentosa were able to inhibit Candida albicans with minimum inhibitory concentrations (MICs) of 125, 250 and 125 µg mL-1, respectively. The methanol crude extract, dichloromethane and alkaloid fractions inhibited selectively the butyrilcholinesterase (BuChE) at percentages of 63.09, 60.39 and 56.22%, respectively. Aubl. Aubl (Aubl. Rubiaceae, Rubiaceae (Rubiaceae Palicoureeae, Palicoureeae , Palicoureeae) Müll Arg Arg. diseases vasorelaxant antiplasmodial activities species work out 1, 1 (1) 2 (2 megastigma4,7dien3one megastigma47dien3one megastigmadienone megastigma 4,7 dien 3 4 7 3, (3) 4, (4) 5,13epoxy9hydroxymegastigma7en,3one 513epoxy9hydroxymegastigma7en3one epoxyhydroxymegastigmaenone 5,13 epoxy 9 hydroxy en,3 5 13 en 5, (5) 6, 6 (6) 7, (7) 3Opcoumaroylquinic Opcoumaroylquinic O p coumaroylquinic 8, 8 (8) 9, (9) 10 (10 11. 11 . (11) ultrahigh ultra high highresolution resolution UHPLC HRMS/MS HRMSMS HRMS MS megastigmanes carotenoids P MICs (MICs 25 12 mL1, mL1 mL mL-1 respectively extract BuChE (BuChE 6309 63 09 63.09 6039 60 39 60.3 5622 56 22 56.22% (Aubl (1 ( megastigma4 7dien3one 47 (3 (4 13epoxy9hydroxymegastigma7en 3one hydroxymegastigma 513 5,1 en3 en, (5 (6 (7 (8 (9 (11 mL- 630 0 63.0 603 60. 562 56.22 dienone epoxyhydroxymegastigmaen 51 63. 56.2 56.