Posidonia, , Haznedaroglu and Zeybek, 2007

Zidorn, Christian, 2016, Secondary metabolites of seagrasses (Alismatales and Potamogetonales; Alismatidae): Chemical diversity, bioactivity, and ecological function, Phytochemistry 124, pp. 5-28 : 13-16

3.10. Posidonia (9, Posidoniaceae, coasts of the Mediterranean and Australia)

Secondary metabolites of P. oceanica and problems related to some older studies have been reviewed recently ( Heglmeier and Zidorn, 2010) and secondary metabolites known from this species encompassed until then compounds 1–10, 12–18, 20–22, 24–25, 28–31, 36, 43–44, 96–97, 100–101, 123–129, 134–142, 144–145.

In order to avoid a mere replication of the previous review ( Heglmeier and Zidorn, 2010), the details of the isolation and identification of compounds 1–10, 12–18, 20–22, 24–25, 28–31, 36, 43–44, 96–97, 100–101, 123–129, 134–142, 144– 145 in P. oceanica are not repeated here. Instead solely the source publications for each compound are indicated: Phenol 1 ( Cuny et al., 1995; Agostini et al., 1998), phloroglucinol 2 ( Cuny et al., 1995; Agostini et al., 1998), pyrocatechol 3 ( Cuny et al., 1995; Agostini et al., 1998), pyrogallol 4 ( Cuny et al., 1995; Agostini et al., 1998), 4-hydroxybenzaldehyde 5 ( Cuny et al., 1995; Agostini et al., 1998), 3,4-dihydroxybenzaldehyde 6 ( Cuny et al., 1995; Agostini et al., 1998), vanillin 7 ( Cuny et al., 1995; Agostini et al., 1998; Haznedaroglu and Zeybek, 2007, syringa aldehyde 8 ( Cuny et al., 1995; Agostini et al., 1998), benzoic acid 9 ( Cuny et al., 1995; Agostini et al., 1998), p -hydroxybenzoic acid 10 (Cariello et al., 1979; Cuny et al., 1995; Agostini et al., 1998; Dumay et al., 2004), p -anisic acid 12 ( Cuny et al., 1995; Agostini et al., 1998), protocatechuic acid 13 ( Cuny et al., 1995; Agostini et al., 1998), vanillic acid 14 (Cariello et al., 1979; Cuny et al., 1995; Agostini et al., 1998), vanillic acid derivative 15 (Cariello et al., 1979), gallic acid 16 ( Agostini et al., 1998), syringic acid 17 ( Cuny et al., 1995; Agostini et al., 1998), gentisic acid 18 ( Haznedaroglu and Zeybek, 2007), piceol 20 ( Agostini et al., 1998), acetovanillone 21 ( Agostini et al., 1998), acetosyringone 22 ( Cuny et al., 1995; Agostini et al., 1998), cinnamic acid 24 ( Cuny et al., 1995; Agostini et al., 1998; Dumay et al., 2004; Haznedaroglu and Zeybek, 2007), coumaric acid 25 ( Cuny et al., 1995; Agostini et al., 1998; Dumay et al., 2004; Haznedaroglu and Zeybek, 2007), caffeic acid 28 ( Agostini et al., 1998; Dumay et al., 2004; Haznedaroglu and Zeybek, 2007), ferulic acid 29 ( Cuny et al., 1995; Agostini et al., 1998; Dumay et al., 2004; Haznedaroglu and Zeybek, 2007), sinapic acid 30 ( Cuny et al., 1995; Agostini et al., 1998), chlorogenic acid 31 ( Cuny et al., 1995), cichoric acid 36 (Cariello and Zanetti, 1979; Cariello et al., 1979; Haznedaroglu and Zeybek, 2007), phloretin 43 ( Cuny et al., 1995), phloridzin 44 ( Cuny et al., 1995), kaempferol 96 ( Cannac et al., 2006, 2007), quercetin 97 ( Cannac et al., 2006, 2007), isorhamnetin 100 ( Cannac et al., 2006, 2007), myricetin 101 ( Cannac et al., 2006, 2007), 5OE- cholestan-3-ol 123 ( Sica et al., 1984), 5OE- cholest-22 E -en-3-ol 124 ( Sica et al., 1984), 5OE- campestanol 125 ( Sica et al., 1984), 5OEergostanol 126 ( Sica et al., 1984), 5OE-24-methylcholest-24(28)- en-3-ol 127 ( Sica et al., 1984), 5OE- β- sitostanol 128 ( Sica et al., 1984), 5OE- isofucostanol 129 ( Sica et al., 1984), cholesterol 134 ( Sica et al., 1984), desmosterol 135 ( Sica et al., 1984), cholesta-5,22-diene-3β- ol 136 ( Sica et al., 1984), campesterol 137 ( Sica et al., 1984), dihydrobrassicasterol 138 ( Sica et al., 1984), epibrassicasterol 139 ( Sica et al., 1984), brassicasterol 140 ( Sica et al., 1984), 24-methylenecholesterol 141 ( Sica et al., 1984), β- sitosterol 142 ( Sica et al., 1984), isofucosterol 144, ( Sica et al., 1984), and stigmasterol 145 ( Sica et al., 1984).

Since the publication of the review on P. oceanica secondary metabolites ( Heglmeier and Zidorn, 2010), Bitam et al. (2012) reported four neolignans 39–42 from P. oceanica collected in the Gulf of Naples, Italy. Moreover, Hammami et al. (2013) discovered the new sesquiterpene alcohol posidozinol 109 from plants collected off the coast of Tunisia. Additionally, these authors confirmed the occurrence of β- sitosterol 142 in P. oceanica . Harborne and Williams (1976) had reported on the occurrence of partially sulfated caffeoyl quinic acid derivatives in P. oceanica and moreover indicated the presence of not further specified procyanidins in a sample of this taxon collected off the coast of Malta.

Most recently, Grignon-Dubois and Rezzonico (2015) described cichoric acid 36, caftaric acid 35 together with mono- and di- coumaric 33, 34 and ferulic tartaric acid derivatives 37, 38 from P. oceanica . Cichoric acid 36 was unambiguously identified as the major phenolic compound, regardless of the sample or collection site and caftaric acid 35, the second most abundant phenolic in the analyzed samples, was reported for the first time from Posidonia . Moreover, the authors highlighted the pronounced effects of extract handling and of choosing adequate criteria to identify natural compounds in extracts, because their results contrasted sharply with previous studies of P. oceanica . Indeed, ferulic acid 29 was found as a trace compound only and the authors failed to detect any traces of acetosyringone 22.

Additionally, these authors reported traces of rutin 99, isorhamnetin 3- O -glucoside, and isorhamnetin 3- O -rutinoside detected by HPLC (addition in proofs, thus without depiction of isorhamnetin 3- O -glucoside and isorhamnetin 3- O -rutinoside and without compound numbers for these compounds, which have not been reported from any other seagrass source yet).