Encecalin and demethylencecalin are major phytotoxic compounds isolated from Helianthella quinquenervis (Hook) A Gray (Asteraceae), they inhibit photosystem II (from water to 2,5-dibromo-3-methyl-6-isopropyl-1,4 p-benzo-quinone).They retard seed germinati
Pyrenocine A is a fungal metabolite that has been found inP. terrestrisand has diverse biological activities.1It inhibits the asexual spore germination of the plant pathogenic fungiF. oxysporum,F. solani,M. hiemalis, andR. stolonifer(EC50s = 14, 20, 20, and 25 μg ml, respectively). Pyrenocine A is active againstB. subtilis,S. aureus, andE. coli(IC50s = 30, 45, and 200 μg ml, respectively). It inhibits onion seedling elongation (EC50= 4 μg ml). Pyrenocine A is also a phytotoxin that inhibits lettuce seed germination and rice seedling elongation.2,3 1.Sparace, S.A., Reeleder, R.D., and Khanizadeh, S.Antibiotic activity of the pyrenocinesCan. J. Microbiol.33(4)327-330(1987) 2.Sato, H., Konoma, K., and Sakamura, S.Phytotoxins produced by onion pink root fungus, Pyrenochaeta terrestrisAgric. BioI. Chem.43(11)2409-2411(1979) 3.Sato, H., Konoma, K., Sakamura, S., et al.X-Ray crystal structure of pyrenocine A, a phytotoxin from Pyrenochaeta terrestrisAgric. BioI. Chem.45(3)795-797(1981)
8-Epixanthatin, a light-induced growth inhibitor, mediates the phototropic curvature in sunflower (Helianthus annuus) hypocotyls, it can induce germination of O. cumana at nano- to micromolar concentrations. 8-Epixanthatin has antiprotozoal activity.
Sphynolactone-7 (SPL7) acts as an agonist for the Striga hyposensitive to light receptor 7 (ShHTL7) found in the parasitic plant Striga hermonthica. SPL7 selectively targets ShHTL7 with an IC50 of 0.31 µM, demonstrating higher specificity compared to ShHTL2-6, ShHTL9-10, and the strigolactone receptor AtD14 at a concentration of 10 µM, though it still inhibits ShHTL8 and ShHTL11 with IC50s of 1.2 and 7.8 µM, respectively. This compound triggers fatal germination of Striga hermonthica seeds in the absence of a host by inducing suicidal germination at a minimum effective concentration of 10 fM. Additionally, SPL7 can reduce the emergence of this obligate parasite from the soil and alleviate Striga hermonthica-induced senescence in maize when applied at a 10 nM concentration to the soil of maize and Striga hermonthica seed co-cultures.
A mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate has antifungal activity , it shows the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri.
Sphingosine (d14:1) is a bioactive sphingolipid that has been found in B. mori (silkworm), P. clarkii (crayfish), and A. aurita (jellyfish) extracts. It increases the germination rate of N. rileyi, an entomopathogenic fungus, with an EC50 value of 10.2 nM. Sphingosine (d14:1) inhibits protein kinase C (PKC) in vitro (IC50 = 7.3 mol%) as well as superoxide generation induced by phorbol 12-myristate 13-acetate in neutrophils and reduces growth of CHO cells (IC50s = 19 and 8 μM, respectively).