Syntheses of C33-, C35-, and C39-Peridinin and Their Spectral Characteristics

Abstract

Peridinin, a nor-carotenoid, exhibits an exceptionally high energy transfer efficiency to chlorophyll a in photosynthesis in the sea. This efficiency would be related to the unique structure of peridinin. To answer the question of why peridinin possesses the irregular C37 skeleton, we have achieved the synthesis of three peridinin derivatives. Their ultrafast time-resolved optical absorption and Stark spectra measurements have shown the presence of the characteristic intramolecular charge transfer state and the featured electrostatic properties of peridinin.

The Nature of the Intramolecular Charge Transfer State in Peridinin

“…The PCP complex contains the highly substituted carotenoid, peridinin, and chlorophyll-a (Chl-a) in a stoichiometric ratio of 4:1 (2). This carotenoid absorbs solar energy in the blue-green region of the visible spectrum (~470-550 nm) and transfers energy to Chl-a with high efficiency (~95%) (3)(4)(5)(6)(7). Peridinin contains a relatively short C-37 backbone comprised of an allene moiety and a furanic ring (often referred to as a lactone ring), which are conjugated with the p-electron system, in addition to an ester group located on one b-ring and an epoxy group on the opposite b-ring (Fig.…”

Excited state properties of a short π-electron conjugated peridinin analogue

“…In order to explore the nature of the ICT state, several analogues of peridinin having various extents of π-electron conjugation (Figure 1) have been synthesized and characterized spectroscopically and computationally [16–20]. Naturally-occurring peridinin has a C 37 carbon skeleton rather than the typical C 40 system present in most carotenoids [21].…”

Heterocyclic terpenes: linear furano- and pyrroloterpenoids

“…This efficiency would be related to the unique structure of peridinin. 154 Peridinin serves as photosynthesis accessory light harvesting pigment and extends the range of absorption for light-harvesting. It was associated with a protein and chlorophyll a and protects the light-harvesting pigments against photochemical damage caused by singlet molecular oxygen.…”

“…167 C 33 -, C 35 -, and C 39 -peridinins 219-221 were synthesized. 154,168 A C 37 carotenoid, isolated as a mixture of esters 222, were reported from the clam Paphia amabillis (Mimase, Japan). 169…”