Cholic acid anilide is a synthetic bile acid and derivative of cholic acid that inhibits the germination of C. difficile strain R20291 spores in vitro (IC50 = 1.8 μM).1 |1. Sharma, S.K., Yip, C., Esposito, E.X., et al. The design, synthesis, and characterizations of spore germination inhibitors effective against an epidemic strain of Clostridium difficile. J. Med. Chem. 61(15), 6759-6778 (2018).
Cerebroside C is a fungal metabolite and glycosphingolipid that has been found in the rice pathogenic fungusM. grisea.1It induces production of the phytoalexin momilactone A when applied to wounded rice leaves, indicating that cerebroside C is an elicitor of the hypersensitive response in rice. Cerebroside C increases germination rate and reduces germination time in wheat seeds in a concentration-dependent manner at 4°C.2It also increases root length, fresh weight, and dry weight of wheat seedlings when used at a concentration of 20 μg/ml at 4°C, indicating increased chilling tolerance. 1.Koga, J., Yamuchi, T., Shimura, M., et al.Cerebrosides A and C, sphingolipid elicitors of hypersensitive cell death and phytoalexin accumulation in rice plantsJ. Biol. Chem.273(48)31985-31991(1998) 2.Li, H.-X., Xiao, Y., Cao, L.-L., et al.Cerebroside C increases tolerance to chilling injury and alters lipid composition in wheat rootsPLoS One8(9)e73380(2013)
Germicidin A is a pyranone originally derived from S. viridochromogenes that acts as a reversible, autoregulative inhibitor of spore germination and hyphal elongation in the genus Streptomyces at concentrations as low as 200 pM. During germination, spores of Streptomyces excrete germicidin A along with other germicidin homologs, which inhibit germination of its own arthrospores. At higher concentrations, germicidin A can inhibit the porcine Na+/K+-activated ATPase (ID50 = 100 μM) and prevent the germination of the cress L. sativum.
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).