Journal Articles - UP

Now showing 1 - 2 of 2

Synthesis and biological evaluation of cyanobacterial-inspired peptides
Casanova, Jannelle R.; Villaraza, Aaron Joseph L.; Salvador-Reyes, Lilibeth (Philippine-American Academy of Science and Engineering, 2024-03-18)
Cyanobacteria are known producers of structurally diverse and potent natural products; the majority are peptides with unique modifications. Yet, there remains a huge underexplored chemodiversity from cyanobacteria. Here, we designed a linear octapeptide as a product of combinatorial peptide design inspired by the natural products from the filamentous cyanobacteria Hapalosiphon welwitschii and Leptolyngbya sp. The target peptide was synthesized via solid-phase peptide synthesis (SPPS) using fluorenylmethyloxycarbonyl-protecting group (Fmoc) strategy. Structural diversity was expanded by the substitution of unnatural amino acids to yield five analogues. The structure and sequence of the synthesized peptides were confirmed using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Biological activity evaluation was done; with none of the peptides showing antimicrobial or cytotoxic activities against microbial pathogens and mammalian cells, respectively. To our knowledge, this study is the first to report a combinatorial peptide design inspired by a natural product and a predicted biosynthetic product. This strategy of peptide design expands the chemistry of a known bioactive natural product with the aid of unexplored cyanobacterial biosynthetic gene clusters.
This study was funded by the Philippine Council for Health Research and Development – Department of Science and Technology through the Discovery and Development of Health Products – Marine Component Program. J.R.C acknowledges scholarship support from the Accelerated Science and Technology Human Resource Development Program of the Department of Science and Technology – Science Education Institute. We acknowledge the assistance of Z. Malto, J. Peran and S. Susana in the conduct of the biological assays. This is MSI Contribution No. 502.
Genistein and daidzein from a sponge-associated fungus (Family: Microstromataceae) show dose and incubation time-dependent Ca2+ influx activity variation
Azcuna, Miguel Enrique Ma.; Acyatan, Zildjian; Manzano, Geminne; Yu, Clairecynth; Aliño, Porfirio Alexander M.; Altamia, Marvin; Salvador-Reyes, Lilibeth; Concepcion, Gisela P. (Philippine Association for the Advancement of Science and Technology, 2023-10-31)
The compounds genistein and daidzein were obtained from the broth culture of a fungus isolated from the Philippine blue sponge Xestospongia sp. Genomic sequencing (18S rRNA) resulted in no exact hits and low sequence similarity (91%) to two species of fungi under the family Microstromataceae: Sympodiomycopsis vantaiensis and Microstromatales sp. Genistein has gained attention in recent years because of its potential to delay the onset of Alzheimer’s disease. This is the first report of genistein and daidzein isolated from a marine-derived fungus. Genistein and daidzein have a wide range of biological activities (e.g., neuroprotective, antimicrobial, anticancer), and this study reports a variation in intracellular [Ca²⁺] levels in dorsal root ganglion cells (DRGs) post-administration depending on dose and incubation time. An incubation time of 10 min resulted in a block effect, which was evidenced by decreased intracellular [Ca²⁺] levels. A dose-response was observed as the intensity of intracellular [Ca²⁺] decreased further at a higher dose. Conversely, an incubation time of 5 min resulted in an increase effect which was evidenced by decreased intracellular [Ca²⁺] levels. The similarity of these compounds with potent estrogens indicates that estrogen-mediated receptor signaling is the mechanism of action for the increase effect. The block effect, however, could be caused by a variety of factors, such as neurotoxicity or an ER stress response that results in the release of pro- and anti-apoptotic proteins. These findings confirm the ability of genistein to regulate [Ca²⁺] influx and the expression of apoptosis-related proteins. Further studies should investigate these mechanisms to understand the neuroprotective activities of genistein and daidzein.
We thank the Drug Discovery and Health Products (DDHP) – Marine Component Project 1 for providing the sponge sample for fungal isolation. We thank Dr. Eizadora Yu of the Institute of Chemistry, University of the Philippines Diliman for providing fungal primers for DNA extraction and obtaining DNA sequences from the fungal sample.

Journal Articles - UP - MSI

Browse

Filters

Settings

Sort By

Results per page

Search Results