12 Afra Khiralla, Rosella Spina, Sakina Yagi et al.
Guanacastepene, a novel diterpenoid produced by an unidentified fungus from
the branch of Daphnopsis americana growing in Guanacaste, Costa Rica, was
shown to be antibacterial against methicillin-resistant Staphylococcus aureus
and vancomycin-resistant Enterococcus faecium (Tan and Zou, 2001). Taxol
originally characterized from the inner bark of the Pacific yew, Taxus
brevifolia, is an efficacious anticancer diterpene found in extremely small
quantities in slowly growing Taxus species. Taxol has been isolated from
Taxomyces andreanae an endophytic fungus recovered from T. brevifolia
(Stirele et al., 1993).
6.2.5. Quinones
Some endophytes produced quinones displaying significant growth
inhibition against phytopathogens such as spiroketals from Edenia
gomzpompae (Wiyakrutta et al., 2004). Torreyanic acid is an unusual dimeric
quinone isolated from Pestalotiopsis microspora, an endophyte of Torreya
taxifolia (Lee et al., 1996). Insecticidal rugulosin was characterized from
Hormonema dematioides, an endophytic fungus of balsam fir. from cultures of
an unidentified endophyte obtained from an eastern larch (Larix laricina)
needle, 8,1’,5’-trihydroxy-3’,4’dihydro-1’H-[2,4’]binaphthalenyl-1,4,2’-trione
was characterized as a toxin to spruce budworm larvae (Findlay et al., 1997).
Preussomerin N 1 , palmarumycin CP4a, and palmarumycin CP 5 were new ras
farnesyl-protein transferase inhibitors produced by an endophytic
Coniothyrium sp. (Tan and Zou, 2001). A highly hydroxylated quinone
altersolanol A, characterized from phytopathogenic Alternaria spp., was
reisolated from an endophytic Phoma multirostrata with its antibacterial
activity disclosed (Yang et al., 1994).
6.2.6. Peptides
Many peptides produced by endophytes displayed significant
antimicrobial activities, such as leucinostatin A produced by Acremonium sp.
(Strobel et al., 1997a). Leucinostatin A was isolated almost forty years ago
from cultures of Penicillium lilacum. It has received much attention over the
years, because of its potent biological activity against several different cell
lines. Acremonium sp., isolated from Taxus baccata, was also shown to
produce Leucinostatin A and leucinostatin A di-O-b-glucoside when grown in
liquid culture (Kharwar et al., 2011). The cyclopeptides echinocandins A, B, D
and H, were produced by Aspergillus rugulosus and A. nidulans var.
echinulatus. Further they were isolated from endophytes Cryptosporiopsis sp.
and Pezicula sp. in Pinus sylvestris and Fagus sylvatica respectively, and