Integracides F and G: New tetracyclic triterpenoids from the endophytic fungus Fusarium sp. Sabrin R.M. Ibrahim a,b, *, Gamal A. Mohamed c,d , Samir A. Ross e a Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah Al Munawwarah 30078, Saudi Arabia b Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt c Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia d Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt e National Center for Natural Products Research, Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, MS 38677, USA A R T I C L E I N F O Article history: Received 18 November 2015 Accepted 21 December 2015 Available online xxx Keywords: Fusarium sp. Integracides Triterpenoids Anti-microbial Anti-malarial Anti-leishmanial Cytotoxic A B S T R A C T Two new tetracyclic triterpenoids: integracides F (1) and G (2) have been isolated from the endophytic fungus Fusarium sp. isolated from the roots of Mentha longifolia L. (Labiatae) growing in Saudi Arabia. Their structures were established by UV, IR, 1D ( 1 H and 13 C), 2D ( 1 H- 1 H COSY, HMQC, HMBC, and NOESY) NMR, and HRESIMS spectral data, in addition to comparison with literature data. The isolated compounds were evaluated for their anti-microbial, anti-malarial, anti-leishmanial, and cytotoxic activities. Compound 1 and 2 displayed potent cytotoxic activity towards BT-549 and SKOV-3 with IC 50 values of 1.97 and 0.16 mg/mL and 1.76 and 0.12 mg/mL, respectively compared to doxorubicin (IC 50 1.61 and 0.095 mg/mL, respectively). Moreover, they exhibited significant anti-leishmanial activity towards Leishmania donovani with IC 50 values of 3.74 and 2.53 mg/mL, respectively and IC 90 values of 5.11 and 8.89 mg/mL, respectively. ã 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved. 1. Introduction Endophytic microorganisms are bacteria or fungi that live inside plant tissues, without causing damage or disease symptoms to their hosts (Elkhayat et al., 2015; deSouza et al., 2011). The secondary metabolites produced by these microorganisms are a valuable repository of natural bioactive compounds, many of which have been identified as useful research reagents and potential drug candidates (Ibrahim et al., 2015; Meinwald and Eisner, 2008; Geris dos Santos and Rodrigues-Fo, 2003). Fusarium sp. are a widespread cosmopolitan group of fungi and commonly colonize aerial and subterranean plant parts, either as primary or secondary invaders (El-Kazzaz et al., 2008). Fusarium sp. is well known for the production of integracides, which are a class of a tetracyclic 4,4-dimethylergostane triterpenoids containing a 12-acetyl-D 8,14 -diene-11-ol moiety. They have been shown to possess elastase, rhinovirus 3C protease, HIV-1 integrase, and cholesteryl ester transfer protein inhibitory activities (Singh et al., 2003a,b; Singh, 2000; Tabata et al., 1999; Brill et al., 1996). As part of an ongoing search for bioactive compounds from endophytic fungi, we have identified two new tetracyclic triterpenoids: integracides F (1) and G (2) from Fusarium sp. isolated from the roots of Mentha longifolia L. (Fig. 1). The fungal EtOAc extract was subjected to Sephadex LH-20, silica gel, and RP-18 column chromatography to yield compounds 1 and 2. Herein, we report the isolation and structure elucidation as well as anti-microbial, anti-malarial, anti-leishmanial, and cytotoxic activities of the new compounds. 2. Results and discussion Compound 1 was obtained as colorless powder. Its HRESIMS spectrum gave a pseudo-molecular ion peak at m/z 557.3839 (calcd. for C 34 H 53 O 6 , 557.3842 [M + H] + ) compatible with the molecular formula C 34 H 52 O 6 , requiring nine degrees of unsatura- tion. The IR spectrum showed characteristic absorption bands at 3435 (hydroxyl group), 1723 (ester group), and 1664 and 885 (exocyclic di-substituted double bond) cm 1 . The UV spectrum showed an absorption band at l max 248 nm characteristic for a heteroannular diene system (Singh et al., 2003b). Compound 1 was 43 mass units and one degree of unsaturation more than intergracide B, indicating the presence of an additional acetyl group in 1 . The NMR spectral data of 1 were similar to intergracide B previously isolated from Fusarium sp. (Singh et al., 2003a,b). The * Corresponding author. E-mail address: sabrinshaur@gmail.com (S.R.M. Ibrahim). http://dx.doi.org/10.1016/j.phytol.2015.12.010 1874-3900/ ã 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved. Phytochemistry Letters 15 (2016) 125–130 Contents lists available at ScienceDirect Phytochemistry Letters journa l home page : www.e lsevier.com/loca te/phyt ol