Halophila

Zidorn, Christian, 2016, Secondary metabolites of seagrasses (Alismatales and Potamogetonales; Alismatidae): Chemical diversity, bioactivity, and ecological function, Phytochemistry 124, pp. 5-28 : 10-12

3.6. Halophila (10, Hydrocharitaceae, tropical coasts of the West

Indies, the Indian and Pacific Oceans)

Harborne and Williams (1976) reported partially characterized caffeoylquinic acid sulfates from Halophila baillonis and H. engelmannii . In H. baillonis the authors moreover detected a partially characterized ssavone O -sulfate derivative.

In an early chemosystematic paper, McMillan (1983) correlated the occurrence of sulfated ssavonoids (unfortunately not further characterized) and the leaf morphology (small-leaved versus large-leaved) in taxa from the H. ovalis – H. minor group from the Pacific Islands and Australia. The author reported a perfect correlation of chemical and morphological characters with sulfated ssavonoids only and consistently occurring in the large-leaved populations investigated.

Meng et al. (2008) reported on ssavonoids of Halophila johnsonii . Compounds 47, 57, 79, 80, 81, 82, 87, 88, 89, 90, 93, and 94 were recorded in both rhizomes and leaves while the occurrence of 86 and 78 was restricted to the rhizomes. The identity of a fifteenth compound reported by these authors remains unclear because there is a mismatch between the indicated figure and the name (myricetin), we therefore omit this record.

Gaul et al. (2011) identified 2,3,4,5-tetrabromo-1-methylpyrrole 154 in H. ovalis collected off the coast of Queensland, Australia. Though the authors assumed that this compound was not synthesized by the seagrass itself but taken up from the environment, they suspect a natural (marine bacteria) rather than an industrial source for this compound.

Halophila stipulacea yielded two structurally unique macrocyclic diterpene glycoside methylglucaryl derivatives 117 and 118 ( Gavagnin et al., 2007; Carbone et al., 2008). Moreover, Mollo et al. (2008) mentioned the ssavonoids apigenin 47, genkwanin 53, and chrysoeriol 67 from this species. Bitam et al. (2010) reported the ssavonoids 48, 50, 52, 54, 55, 68, and 70 from H. stipulacea collected off the coast of Greece. Mollo et al. (2015) in more detail discussed the chemistry of the species pair composed of the seagrass H. stipulacea and the mollusk Syphonota geographica as an example of interdependent bioinvasions in their position paper.