2018 Springer Science+Business Media, LLC
Chemistry of Natural Compounds, Vol. 54, No. 3, May, 2018
CHEMICAL CONSTITUENTS OF THE ENDOPHYTIC FUNGUS
Phomopsis asparagi ISOLATED FROM THE PLANT Peperomia sui
and Ih-Sheng Chen
Investigation of the ethyl acetate-soluble layer from the liquid fermentation of Phomopsis asparagi, an
endophytic fungus isolated from the Taiwanese endemic plant of Peperomia sui T.T. Lin & S.Y. Lu, led to the
isolation of a new cytochalasin, phomocytochalasin A (1), and one benzenoid, phomoaspardiol (2), which
was isolated from nature for the first time, along with eight known compounds including two cytochalasins,
four benzenoids, one chromone, and one steroid. The structures of the isolates were established by
spectroscopic methods, including UV, IR, HR-ESI-MS, and extensive 1D and 2D NMR techniques, as well as
by comparison with literature reports. Among the isolates, cytochalasin J showed androgen receptor (AR)
antagonism with the IC
value of 6.20
Keywords: Phomopsis asparagi, Peperomia sui, cytochalasin, benzenoid, androgen antagonism.
Endophytic fungi, which inhabit normal tissues or organs of host plants without causing apparent pathogenic symptoms,
have been shown to be a promising source with diverse bioactive natural products [1–3]. In continuation of our chemical and
biological investigations of endophyte-generated metabolites, one of the hits resulting from our efforts was the strain 12F0670,
which was identified as Phomopsis asparagi by its 18S rRNA, which gave a 100% sequence similarity to those accessible by
BLAST analyses of available Phomopsis asparagi sequences (NCBI accession number JQ614002.1), isolated from the whole
plant of Peperomia sui Lin & Lu and ascertained to be able to produce bioactive metabolites during its liquid fermentation.
Previous chemical investigations of a class of the widely distributed endophytic fungi of the genus Phomopsis (family
Diaporthaceae) have yielded several interesting natural products, including cytochalasins, oblongolides, phomoenamides,
phomoeuphorbins A–D, phomoxanthones, and herbarumins I and II, some of which were shown to possess antitumor,
antimicrobial, antiviral, antimalarial, antitubercular, and antiphytotoxic activities [4–9]. To date, there is only one report on the
bioactive secondary metabolites isolated from Phomopsis asparagi . Here, we report the isolation and structure elucidation
of the new compounds, as well as their biological activities. We describe the secondary metabolites from the endophytic fungi
of the plant P. sui for the first time.
The EtOAc extract of the whole broth of the fungal strain was repeatedly fractionated by a combination of
chromatography on silica gel, MPLC, gel filtration over Sephadex LH-20, and preparative HPLC purification to afford
compounds 1–10. Besides the new compounds (1 and 2), the other eight compounds (3–10) were known by comparison of
their spectra and physical data with the available literature [11–18].
1) Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, 807, Kaohsiung,
Taiwan, e-mail: firstname.lastname@example.org; 2) School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, 807,
Taiwan; 3) Bioresource Collection and Research Center, Food Industry Research and Development Institute, 300, Hsinchu,
Taiwan. Published in Khimiya Prirodnykh Soedinenii, No. 3, May–June, 2018, pp. 428–431. Original article submitted
November 2, 2016.