Med Chem Res DOI 10.1007/s00044-017-1989-4 MEDICINAL CHEMISTR Y RESEARCH ORIGINAL RESEARCH Isolation of three new metabolites and intervention of diazomethane led to separation of compound 1 & 2 from an endophytic fungus, Cryptosporiopsis sp. depicting cytotoxic activity Sunil Kumar 1,2 ● Yedukondalu Nalli 1,2 ● Masroor Qadri 2,3 ● Syed Riyaz-Ul-Hassan 2,3 ● Naresh K. Satti 1 ● Vivek Gupta 4 ● Shashi Bhushan 5 ● Asif Ali 1,2 Received: 8 February 2017 / Accepted: 10 July 2017 © Springer Science+Business Media, LLC 2017 Abstract The discovery of three new natural products (1, 4, and 5), one semi-synthetic derivative (3) along with two known compounds (2 and 6) were isolated from an endo- phytic fungus Cryptosporiopsis sp. The structural elucida- tions of 1–6 were authenticated by one-dimensional and two-dimensional nuclear magnetic resonance, mass spec- troscopy, and X-ray diffraction analysis. Herein, we inter- vention of diazomethane as tool that help in the crystallization and isolation of inseparable mixtures of compounds 1 and 2. Compounds (1–6) were screened for cytotoxic activity against six cancer cell lines in which the 4-epi-ethisolide (2) exhibited moderate activity with IC 50 values 11 μM in HL-60, whereas the compound 3 lost its cytotoxic potentiality, but it displayed moderate anti- microbial activity. The result illustrates that the methylene moiety in 2 plays significant role in cytotoxic potential. Keywords Endophytic fungus ● Cryptosporiopsis sp. ● Cytotoxicity ● Chemical engineering Introduction Plant endophytic fungi live in the intercellular spaces of plant tissues for all or part of their life cycle without causing apparent pathogenic symptoms. Endophytes are a poorly investigated group of microorganisms and have proved to be an important source of bioactive and chemically novel metabolites with an enormous metabolic diversity (Strobel and Daisy 2003; Nalli et al. 2017). These organisms have the ability to produce a plethora of substances with unique structures and interesting biological activities to modern medicine, agriculture, and industry. Recently, increasing the number of reports on their identification and on the pro- duction of secondary metabolites witnessed the enormous potential of endophytes as rich and reliable natural resource (Strobel 2003). The genus Cryptosporiopsis, with over 15 species, has attracted considerable attention as a source of numerous compounds with antimicrobial and anticancer activities (Debbab et al. 2012; Kharwar et al. 2011; Kumar et al. 2013). Cryptosporiopsis species are anamorphs of ascomycetes in the genera Pezicula and Neofabraea Der- mataceae and have been isolate as endophytes of several plants (Sigler et al. 2005; Zilla et al. 2013). With the aim of discovering novel bioactive metabolites from endophytic fungi, we investigated the chemical constituents of the Sunil Kumar and Yedukondalu Nalli contributed equally to this work. * Asif Ali asifali@iiim.ac.in 1 Natural Product Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu- Tawi, J&K 180001, India 2 Academy of Scientific and Innovative Research, CSIR-Indian Institute of Medicine, Canal Road, Jammu-Tawi, J&K 180001, India 3 Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu-Tawi, J&K 180001, India 4 Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India 5 Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India Electronic supplementary material The online version of this article (doi:10.1007/s00044-017-1989-4) contains supplementary material, which is available to authorized users.