Fernando, H., Gunatilaka, A., Kumar, V., Weeratunga, G., Tezuka, Y., & Kikuchi, T. (1988). Two new quinone-methides from cassine balae: Revised structure of balaenonol. Tetrahedron Letters, 29(3), 387-390.
Abstract:
The structure of balaenol, a new quinone-methide triterpene isolated from Cassine balae has been deduced as 1 and the structure of the previously isolated balaenonol has been revised as 2 from their spectral data including 2-D heteronuclear 1H13C shift correlated NMR spectra and n.O.e studies. © 1988.
Padumadasa, C., Xu, Y., Wijeratne, K., U'Ren, J., Arnold, E., & Gunatilaka, L. (2017). Cytotoxic and Non-Cytotoxic Metabolites from Teratosphaeria sp. FL2137, a Fungus Associated with Pinus clausa. Journal of Natural Products. doi:10.1021/acs.jnatprod.7b00838
M., E., Bashyal, B. P., Liu, M. X., Rocha, D. D., M., G., U'Ren, J. M., Gunatilaka, M. K., Arnold, A. E., Whitesell, L., & A., A. (2012). Geopyxins A-E, ent -Kaurane diterpenoids from endolichenic fungal strains geopyxis aff. majalis and Geopyxis sp. AZ0066: Structure-activity relationships of geopyxins and their analogues(1). Journal of Natural Products, 75(3), 361-369.
PMID: 22264149;PMCID: PMC3359839;Abstract:
Four new ent-kaurane diterpenoids, geopyxins A-D (1-4), were isolated from Geopyxis aff. majalis, a fungus occurring in the lichen Pseudevernia intensa, whereas Geopyxis sp. AZ0066 inhabiting the same host afforded two new ent-kaurane diterpenoids, geopyxins E and F (5 and 6), together with 1 and 3. The structures of 1-6 were established on the basis of their spectroscopic data, while the absolute configurations were assigned using modified Mosher's ester method. Methylation of 1-3, 5, and 6 gave their corresponding methyl esters 7-11. On acetylation, 1 and 7 yielded their corresponding monoacetates 12 and 14 and diacetates 13 and 15. All compounds were evaluated for their cytotoxic and heat-shock induction activities. Compounds 2, 7-10, 12, 14, and 15 showed cytotoxic activity in the low micromolar range against all five cancer cell lines tested, but only compounds 7-9, 14, and 15 were found to activate the heat-shock response at similar concentrations. From a preliminary structure-activity perspective, the electrophilic α,β-unsaturated ketone carbonyl motif present in all compounds except 6 and 11 was found to be necessary but not sufficient for both cytotoxicity and heat-shock activation. © 2012 The American Chemical Society and American Society of Pharmacognosy.
Gunatilaka, A. L., Sotheeswaran, S., Sriyani, B., & Balasubramaniam, S. (1981). Isoboldine and lupenone from Neolitsea fuscata. Planta Medica, 43(3), 309-310.
M., L., A., A., G., D., Patitucci, M. L., & Pinto, A. C. (1997). A bioactive seco-rosane diterpenoid from Vellozia candida. Journal of Natural Products, 60(5), 478-481.
PMID: 9170291;Abstract:
Bioassay-directed fractionation of the bioactive alcoholic extracts of Vellozia candida yielded a new 6,7-seco-rosane diterpenoid, candidalactone (1), which showed moderate toxicity toward DNA repair-deficient mutants of Saccharomyces cerevisiae. Another new but inactive rosane diterpenoid, candidenodiol (3), was also obtained.