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Journal Articles - UP - MSI

Permanent URI for this collectionhttps://repository.unesco.gov.ph/handle/123456789/50

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Author: search.filters.author.Acyatan, Zildjian

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    On-resin synthesis of the somatostatin venom analog Consomatin Ro1
    de Boda, Ramoncito Luis; Acyatan, Zildjian; Concepcion, Gisela; Villaraza, Aaron Joseph (Philippine-American Academy of Science and Engineering, 2023-08-29)
    Consomatin Ro1 is a disulfide-containing peptide derived from the venom of the cone snail Conus rolani with a sequence that is similar to the vertebrate peptide hormone somatostatin. It has been shown to preferentially activate human somatostatin receptor subtypes 1 and 4, and to exhibit antinociceptive and antihyperalgesic properties making it an interesting peptide to study and develop as a chemical probe or an analgesic drug. Here, we describe the synthesis of Consomatin Ro1 using an onresin approach wherein the disulfide bond is formed while the peptide is still attached to the resin. This was achieved by selectively removing the methoxytrityl protecting group of Cys residues with a weak acidic mixture, and treating the resulting thiol-containing peptidyl resin with the mild oxidant Nchlorosuccinimide. The strategy yielded a considerably higher amount of the peptide when compared with the previously reported in-solution disulfide formation method.
    This work was funded by the Department of Science and Technology through Project 1. Anti-Pain and AntiNeurodegeneration Drug Candidates: Discovery and Development under the Discovery and Development of Health Products - Marine Component (Phase II) program. The authors would like to thank the Philippine Council for Health Research and Development for monitoring the research project.
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    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.