274 0009-3130/18/5402-0274 2018 Springer Science+Business Media, LLC Chemistry of Natural Compounds, Vol. 54, No. 2, March, 2018 SECONDARY METABOLITES FROM THE FUNGUS Quambalaria cyanescens Daoud W. Bishay, 1 Afaf M. Abdel-Baky, 1 Ahmed M. Moharram, 2 Lourin G. Malak, 1 Radhakrishnan Srivedavyasasri, 3 and Samir A. Ross 3,4* A phytochemical study of the fungus Quambalaria cyanescens led to the isolation of one new natural compound (1), along with four known compounds (2–5). The structures of the isolated metabolites were elucidated based on spectroscopic and spectrometric techniques. The fatty acid composition of Q. cyanescens was determined by GC/MS and found to consist of stearic, myristic, lauric, linoleic, cis-vaccenic, oleic, and pentadecanoic acids. All the isolated compounds were evaluated for their antimicrobial, antimalarial, and antileishmanial activities. Keywords: Quambalaria cyanescens, 3-butylphenol, fatty acids. Quambalaria cyanescens (de Hoog & G. A. de Vries) Z. W. de Beer was provided by Assiut University Mycological Centre (Accessio No. 4123). It has economic significance as Quambalaria infections has caused changes in preferred species of the host plant for commercial plantations in Australia. It is known as a minor pathogen of eucalyptus and close relatives, and also as an isolate from human skin [1–4]. In this study, Q. cyanescens was cultivated and subjected to procedures of extractions and fractionations, which led to the isolation of one new compound (1), along with four known compounds (2–5). The fatty acid composition of Q. cyanescens was determined by GC/MS. By comparison with the library data, retention time, and mass, the peaks were determined as stearic, myristic, lauric, linoleic, cis-vaccenic, oleic, and pentadecanoic acids. All the isolated compounds exhibited no activity in antimicrobial, antimalarial, and antileishmanial assays. Compound 1, obtained as a yellow residue, displayed a sodiated molecular ion [M + Na] + at m/z 173.1016 (calcd for C 10 H 14 ONa + , 173.09432) in the HR-ESI-MS, corresponding to a molecular formula of C 10 H 14 O, suggesting four degrees of unsaturation. The 1 H and 13 C NMR spectra (Table 1) showed signals of four aromatic methines, H 7.09 (dd, J = 2.4, 7.6 Hz)/ C 126.0 (C-6), H 7.12 (d, J = 8.4 Hz)/ C 126.7 (C-4), H 7.49 (d, J = 2.4 Hz)/ C 125.5 (C-2), and H 7.52 (dd, J = 7.6, 8.4 Hz)/ C 125.5 (C-5), for a meta disubstituted benzene ring; in addition to one methyl H 0.69 (t, J = 7.0 Hz)/ C 14.0 (C-4) and three methylenes, H 1.51–1.16 (m)/ C 22.1 (C-3), 29.0 (C-1), and 31.3 (C-2), suggesting the presence of an n-butyl group. The 13 C NMR spectrum also showed resonances for two quaternary carbons 147.6 (C-3) and 146.0 (C-1). The methylene protons of C-2of the n-butyl group showed HMBC correlation with C-3, suggesting the presence of n-butyl substitution at C-3 of the benzene ring. The full assignment of the protons and carbons was confirmed by the HMBC correlations from H-5 (7.52, dd) to C-1 (146.0), from H-6 (7.09, dd) to C-1 (146.0) and C-4 (126.6), and from H-4(0.69) to C-3(22.1) and C-2(31.3). Hence, compound 1 was identified as 3-butylphenol, which is synthetically known [5], but this is the first report of isolation from a natural source. 1) Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, 71526, Assiut, Egypt; 2) Mycological Center, Assiut University, 71515, Assiut, Egypt; 3) National Center for Natural Products, School of Pharmacy, The University of Mississippi, University, MS 38677, USA; 4) Department of BioMolecular Sciences, Pharmacognosy Devision, School of Pharmacy, The University of Mississippi, University, MS 38677, USA, e-mail: sross@olemiss.edu. Published in Khimiya Prirodnykh Soedinenii, No. 2, March–April, 2018, pp. 229–231. Original article submitted October 3, 2016. DOI 10.1007/s10600-018-2322-2