@inproceedings {743,
	title = {Computational investigation of the electronic and energetic landscape of the scytonemin-glucose complex},
	booktitle = {Proceedings of the 44th Samahang Pisika ng Pilipinas Physics Conference},
	year = {2026},
	month = {17-20 Jun 2026},
	pages = {SPP-2026-PC-06},
	address = {Los Ba{\~n}os},
	abstract = {Scytonemin plays a vital role in cellular protection, as a primary UV-dissipating agent found within the cyanobacterial polysaccharide frameworks. It has attracted significant interest in its potential application in sunscreens, cosmetics, and materials science. This paper explores the unexplored intermolecular interactions of scytonemin within the extracellular polysaccharide (EPS) sheath and lipopolysaccharide (LPS) framework. Specifically, the interactions of scytonemin with β-D-glucose, a common component of the EPS/LPS. Our computational workflow integrated an initial automated docking phase (GFN2-xTB and ALPB) for broad conformational sampling. This is followed by geometry optimization, single point energy calculations, and time dependent DFT (TDDFT) simulations. By employing ωB97X-3c with the SMD solvation model (water as the solvent), we quantify the ground and first excited state influence of glucose binding with the scytonemin monomer. Calculated interaction energies for the scytonemin-glucose complexes ranged from -0.267 to -0.426 eV. Analysis of the first excited state energies revealed notable stabilization upon photoexcitation. Orbital analysis and TDDFT simulations revealed that the frontier molecular orbitals remain nearly completely localized on the scytonemin monomer, resulting in the UV absorption maxima of the scytonemin monomer (≈ 307 to 309 nm) showing small red shifting upon binding with β-D-glucose. These findings suggest that scytonemin maintains its electronic structure and photoprotective characteristics even when integrated into the diverse carbohydrate environments of the EPS/LPS matrix.},
	url = {https://proceedings.spp-online.org/article/view/SPP-2026-PC-06},
	author = {Niccolo Armando C. De Castro and Cyrone Benedict T. Recongco and Gennevieve M. Macam}
}
@inproceedings {678,
	title = {Conformational search of scytonemin and its stereoisomers from first-principles: Towards green cosmetics},
	booktitle = {Proceedings of the 42nd Samahang Pisika ng Pilipinas Physics Conference},
	year = {2024},
	month = {3{\textendash}6 Jul 2024},
	pages = {SPP-2024-PA-09},
	address = {Batangas City},
	abstract = {Scytonemin is a UV-absorbing metabolite produced by cyanobacteria that may be used as a sustainable sunscreen ingredient. However, ab initio studies on scytonemin structure and excited states are sparse. We present herewith a theoretical study to predict its molecular structure using density functional theory. Predicted conformational energy barriers from the def2-QZVPP basis and select exchange-correlational functionals were benchmarked against a coupled-cluster calculation at the basis set limit. We show that the <em>E</em> and <em>Z</em> isomeric forms of the scytonemin monomer are planar compounds; moreover, we verify that scytonemin itself, as well as its geometric isomers, is non-planar, and can exist as two stable rotamers in the syn- and anticlinal regimes, the former being the more favorable state. The benchmarking suggests the BHHLYP method predicts torsion barriers well. Studies of scytonemin photochemistry can thus be facilitated by the provided structural parameters.},
	url = {https://proceedings.spp-online.org/article/view/SPP-2024-PA-09},
	author = {Cyrone Benedict T. Recongco and Gennevieve M. Macam}
}