Identification of Secondary Metabolites from the Mangrove-Endophyte Lasiodiplodia iranensis F0619 by UPLC-ESI-MS/MS

Abstract

Lasiodiplodia is a widely distributed fungal genus, frequently found in tropical and subtropical regions where it can cause disease in important crops. It represents a promising source of active secondary metabolites with uses in chemical, pharmaceutical, and agrochemical processes. In this study, the strain Lasiodiplodia iranensis F0619 was isolated from the mangrove Avicennia ger-minans, collected from Sarigua National Park in the Republic of Panama. Fractions of crude extract were analyzed by UPLC-ESI-MS/MS, and five compounds, previously reported from Lasiodiplodia genus were identified, including 11,12-didehydro-7-iso-jasmonic acid (1), 4,5-didehydro-7-iso-jasmonic acid (2), cyclo-(L-Leu-L-Pro) (3), jasmonate-threonine (4), and abscisic acid (5). We describe and analyze their MS/MS fragmentation patterns to confirm the compounds 'chemical structures.

Keywords: Lasiodiplodia iranensis; MS/MS fragmentation analysis; jasmonates; mangrove-endophytes.

Figure 1

Lasiodiplodia iranensis F0619. (a) Colony morphology, front side at 7 days of cultivation; (b) Colony morphology reverse side at 7 days of cultivation; (c,d) Culture on mal extract-agar after 15 days of cultivation; (e) Hyaline paraphysis on MEA; (f) Dark mature conidia. ― scale bar in (e,f) = 10 μm.

Figure 1

Lasiodiplodia iranensis F0619. (a) Colony morphology, front side at 7 days of cultivation; (b) Colony morphology reverse side at 7 days of cultivation; (c,d) Culture on mal extract-agar after 15 days of cultivation; (e) Hyaline paraphysis on MEA; (f) Dark mature conidia. ― scale bar in (e,f) = 10 μm.

Figure 2

Phylogenetic analysis of the ITS region based on the Maximum Likelihood method. The tree was rooted with Penicillium adametzii (accession number MT949920.1) In green, focal strain L. iranensis F0619. There is, next to the branches, the percentage which associated taxa clustered together. The highest log-likelihood values were −1596.61.

Figure 3

Structure of compounds 1–5.

Scheme 1

Generation of fragment at m/z 191 in compounds 1 and 2.

Scheme 2

Generation of fragment at m/z 149 from compounds 1 and 2.

Scheme 3

Generation of fragment at m/z 163 from compounds 1.

Scheme 4

Generation of fragment at m/z 131.1 from compound 1.

Scheme 5

Generation of fragment at m/z 121.1 from compound 1.

Scheme 6

Generation of fragment at m/z 181.3 from compound 2.

Scheme 7

Generation of fragment at m/z 294.2 from compound 4.

Scheme 8

Generation of fragment at m/z 266.2 from compound 4.

Scheme 9

Generation of fragment at m/z 198.3 from compound 4.

Scheme 10

Generation of fragment at m/z 194.1 from compound 3.

Scheme 11

Generation of fragment m/z 183.2 from compound 3.

Scheme 12

Generation of fragment at m/z 86.3 from compound 3.

Scheme 13

Generation of fragment at m/z 248.2 from compound 5.

Scheme 14

Generation of fragment at m/z 221.2 from compound 5.

Scheme 15

Generation of fragment at m/z 180.1 from compound 5.