Halenaquinone Derivatives from Tropical Marine Sponge Xestospongia sp.

Indoleamine 2,3-Dioxygenase Inhibitors Isolated from the Sponge Xestospongia vansoesti: Structure Elucidation, Analogue Synthesis, and Biological Activity

“…The molecular formula and the 1 H and 13 C NMR spectra obtained for 2 were nearly identical to those reported for xestosaprol N (5) (Table 1, Supporting Information). 17 2), which was confirmed by analysis of the HMBC data obtained for the analogues 3 and 4 prepared by unambiguous synthesis (vide infra and Supporting Information). tROESY data showed that the C-3 OH and Me-20 were trans as in 1.…”

“…The molecular formula and the 1 H and 13 C NMR spectra obtained for 2 were nearly identical to those reported for xestosaprol N ( 5 ) (Table 1, Supporting Information). Analysis of the 1D and 2D NMR data for 2 revealed the diosphenol, naphthoquinone, dioxydihydrothiazine ring, and methyl cyclohexyl ring system substructures present in xestosaprol N ( 5 ). However, careful inspection of the 2D NMR data obtained for 2 revealed that the aromatic methine H-18 (δ 8.33) showed strong HMBC correlations to the most deshielded carbonyl resonance at δ 178.5 (C-16), while the other aromatic methine resonance H-11 (δ 8.63) showed HMBC correlations to the diosphenol carbonyl resonance at δ 177.0 (C-9) and the more shielded quinone carbonyl resonance at δ 173.0 (C-13).…”

Marine natural products

“…568 Xestosaprol N 616 has been reported from a Xestospongia sp. (Weno Is., Chuuk State, Federated States of Micronesia), 569 while the antifungal aurantoside K 617 was isolated from a species of Melophlus (Cicia, Lau group of Fiji). 570 Iotrochamides A 618 and B 619 (Iotrochota sp., Curacao Is., Queensland) were both moderately selective against Trypanosoma brucei.…”

Total Synthesis of (−)-Xestosaprol N and O

“…In 2012, xestosaprol N (5) was isolated from the Micronesian marine sponge by Lee and co-workers and exhibited weak inhibition activity against NCI-H23 and PC-3, with values of GI 50 28.21 and 28.95 μg/mL. 6 Two years later, Andersen and Mauk et al isolated xestosaprol O (6) from Xestospongia vansoesti and synthesized its deoxy analogue via the Sato reaction as a key step. 7 Further in vitro research indicated that xestosaprol O (6) exerts the enzyme indoleamine 2,3dioxygenase (IDO) inhibition (IC 50 = 4 μM).…”

“…Total synthesis strategies have been developed using Diels–Alder reactions, − Heck reactions, , or metal promoted cyclization as key steps. , The derivatives of halenaquinone-type natural products without a furan ring were also discovered in recent years. In 2012, xestosaprol N ( 5 ) was isolated from the Micronesian marine sponge by Lee and co-workers and exhibited weak inhibition activity against NCI-H23 and PC-3, with values of GI 50 28.21 and 28.95 μg/mL . Two years later, Andersen and Mauk et al isolated xestosaprol O ( 6 ) from Xestospongia vansoesti and synthesized its deoxy analogue via the Sato reaction as a key step .…”