Endophytes Crop Productivity and Protection Volume 2 (Sustainable Development and Biodiversity)

O

O

O

H 3 C

OH

OH

CH 3

O

CH 3

(7)

O

HO O

HO O

OH

O

(8)

H O

OH

CH 3

H 3 C

O

O

H 3 C O

H 3 C

H 3 C

(9)

OH

CH 3

H 3 C

O

H 3 CO

H 3 C

H 3 C

O

OH

(10)

RO

O

H

H

OH

HO

H

(11)R = H

(12) R = CH 3

Besides the above-mentioned endophytic fungal antibiotic metabolites, there is a

plethora of endophytes, with no certain compound isolated, but have been reported

to show strong antibiotic activity for tested microorganisms. Methanol extract of a

new endophytic fungusColletotrichum gloeosporioidesfrom the medicinal plant

Vitex negundo with antimicrobial activity against methicillin-penicillin-and/or

vancomycin-resistant clinical strains ofS. aureus, is an example for the former

statement (Arivudainambi et al. 2011 ).

Cytonic acid A and B(13, 14)are two novel human cytomegalovirus protease

inhibitors isolated from endophytic fungusCytonaemasp. (Guo et al. 2000 ). The

absence of appropriate antiviral screening systems in most programs is the main

limitation in this type of compound discovery. Cytochalasins are alkaloids, com-

mon in endophyticXylaria,Phoma,and Hypoxylonspp. exhibiting antitumor

activities (Wagenaar et al. 2000 ). Torreyanic acid(15), is a selectively cytotoxic
unusual dimeric quinone isolated fromPestalotiopsis microsporaendophytic to the

endangered treeTorrya taxifolia(Lee et al. 1996 ). Torreyanic acid, in general has

demonstrated 5–10 times more potency to several cancer cell lines that are sensitive

to protein kinase C agonists and caused cell death by apoptosis (Lee et al. 1996 ).

A recent study has reported a new epitetrathiodioxopiperizine, secoemestrin D(16)

from an endophytic fungal strain Emericella sp., occurred in mesophyll of

Astrgalus lentiginosus.Secoemestrin D exhibited significant cytotoxic activity with

IC 50 values ranging from 0.06 to 0.24μM and moderate selectivity to human

glioma and metastatic breast adenocarcinoma cell lines (Xu et al. 2013 ).

198 P.B. Ratnaweera and E.D. de Silva

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