Extraction optimization and reactivity of 7¿-acetoxy-6ß-hydroxyroyleanone and ability of its derivatives to modulate PKC isoforms

• Type: Article in International Scientific Journal
• Date: 2024-01-01

Authors

Lucilia Saraiva (Author) FFUP

Journal

Title: Scientific Reports

Vol. 14 No. Article 7705

ISSN: 2045-2322

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-012-MMZ

DOI: 10.1038/s41598-024-67384-0

Abstract (EN): Protein kinase C is a family of kinases that play important roles in carcinogenesis. Medicinal plants from Plectranthus spp. (Lamiaceae) are a well-known source of interesting abietanes, such as 7 alpha-acetoxy-6 beta-hydroxyroyleanone (Roy). This study aimed to extract and isolate Roy from P. grandidentatus G & uuml;rke, comparing two extraction methods (CO2 supercritical and ultrasound-assisted acetonic extraction), and design new royleanone derivatives for PKC modulation focusing on breast cancer therapy. The concentration of Roy in the extracts was determined by HPLC-DAD. The supercritical extraction method yielded 3.6% w/w, with the presence of 42.7 mu g mg-1 of Roy (yield of 0.13%), while ultrasound-assisted acetonic extraction yielded 2.3% w/w, with the presence of 55.2 mu g mg-1 of Roy (yield of 0.15%). The reactivity of Roy was investigated aiming at synthetizing new ester derivatives through standard benzoylation and esterification reactions. The benzoylated (Roy-12-Bz) and acetylated (Roy-12-Ac) derivatives in the C12 position were consistently prepared with overall good yields (33-86%). These results indicate the 12-OH position as the most reactive for esterification, affording derivatives under mild conditions. The reported di-benzoylated (RoyBz) and di-acetylated (RoyAc) derivatives were also synthesized after increasing the temperature (50 degrees C), reaction time, and using an excess of reagents. The cytotoxic potential of Roy and its derivatives was assessed against breast cancer cell lines, with RoyBz emerging as the most promising compound. Derivatization at position C-12 did not offer advantages over di-esterification at positions C-12 and C-6 or over the parent compound Roy and the presence of aromatic groups favored cytotoxicity. Evaluation of royleanones as PKC-alpha, beta I, delta, epsilon, and zeta activators revealed DeRoy's efficacy across all isoforms, while RoyPr showed promising activation of PKC-delta but not PKC-zeta, highlighting the influence of slight structural changes on isoform selectivity. Molecular docking analysis emphasized the importance of microenvironmental factors in isoform specificity, underscoring the complexity of PKC modulation and the need for further exploration.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12