Oxygenated Terpenes from Indo-Pacific Nudibranchs: Scalarane Sesterterpenes from Glossodoris hikuerensis and 12-Acetoxy Dendrillolide A from Goniobranchus albonares

Abstract

Two new scalarane sesterterpenes (1, 2) were characterized from an organic extract of a single specimen of the nudibranch Glossodoris hikuerensis collected from Bali. 12-Acetoxy dendrillolide A (10) was identified from specimens of Goniobranchus albonares, while dendrillolide A (11) was isolated both from G. albonares and its sponge diet. The structures and relative configuration of the new metabolites have been elucidated by analysis of their spectroscopic data.

Bioactive Compounds from Marine Heterobranchs

“…For human HeLa-S3 cancer cells, IC 50 values were 0.5 nM for aplyronine A (191) 191) is registered at the NCI database as NSC687160, with a mean IC 50 value of~0.2 nM in the 60 cancer cell lines, but being selective against some cell lines and most active against MDR cancer cell line NCI/ADR-RES, with an IC 50 value of~0.2 nM, as well as for P388 murine leukemia, Lewis murine lung carcinoma, Erhlich murine carcinoma, colon 26 murine carcinoma, and B16 murine melanoma, but very moderated against HOP-92 (NSCLC), OVCAR-4 (ovarian cancer), TK-10 and UO-31 (renal cancers), and BT-549 and T47-D (breast cancers) [652]. Aplyronine A (191) also presents proapoptotic effects in cancer cells [46]. Aplyronine A (191) was in fact suggested to inhibit the actin microfilaments, since it can depolymerize F-actin and inhibit actin polymerization, forming a complex with monomeric actin (1:1), in a similar way to the well-known tubulin inhibitors vincristine and vinblastine currently employed in some cancer treatments [479,659,660].…”

“…These variations resulted in different potencies when deterring feeding in the allopatric, generalist rock-pool shrimp P. serenus , but in all cases, the specimens showed deterrent activity [ 187 , 188 ]. Other Goniobranchus species, such as G. albonarus , present diterpenes and nor-diterpenes obtained from their sponge prey, but they have not been tested for feeding deterrence [ 189 , 190 , 191 , 192 ].…”

“…Many reviews have dealt with this topic in depth, and, therefore, we include here only a brief summary of all the activities described [31,42,479]. Among the most active compounds, it is worth mentioning jorumycin (189) from the doridacean Jorunna funebris, ulapualides (190) from Hexabranchus sanguineus, kabiramides (62) from Hexabranchus sp., aplyronines (191) and dolastatins (192) from the anaspidean Dolabella auricularia, and bursatellanins (193) from Bursatella leachii, as well as kahalalides (194) from the sacoglossan Elysia rufescens, all of which are under clinical trials for antitumoral activity [36,43,45,46,479]. It is important to remember that cytotoxic, anticancer, and antitumoral compounds are strongly needed, since cancer remains one of the deadliest diseases worldwide [42].…”

“…kurodai has been widely studied over the years, containing a series of compounds that include polyketide macrolides, halogenated and brominated mono-and di-terpenes, brominated sesquiterpenoids, sterols, alkaloids, peptides, and others [1,2]. Aplyronines A-H (191,(290)(291)(292)(293) are polyketide macrolides found in Pacific specimens along with aplaminal (294), some of them being tested in antitumor clinical trials [46,[652][653][654][655][656]. For human HeLa-S3 cancer cells, IC 50 values were 0.5 nM for aplyronine A (191) 191) is registered at the NCI database as NSC687160, with a mean IC 50 value of~0.2 nM in the 60 cancer cell lines, but being selective against some cell lines and most active against MDR cancer cell line NCI/ADR-RES, with an IC 50 value of~0.2 nM, as well as for P388 murine leukemia, Lewis murine lung carcinoma, Erhlich murine carcinoma, colon 26 murine carcinoma, and B16 murine melanoma, but very moderated against HOP-92 (NSCLC), OVCAR-4 (ovarian cancer), TK-10 and UO-31 (renal cancers), and BT-549 and T47-D (breast cancers) [652].…”

Oxygenated Diterpenes from the Indo-Pacific Nudibranchs Goniobranchus splendidus and Ardeadoris egretta

“…Typically, these mollusks contain terpene metabolites [1][2] that may be involved in their chemical defense [3][4][5]. Our recent studies have investigated the chemistry and anatomical location of metabolites in a range of chromodorid mollusks, including from the genera Glossodoris [6][7][8], Chromodoris [9][10][11], and Goniobranchus [8,12,13]. We found that specimens of Goniobranchus splendidus collected near Mooloolaba, South East Queensland contained "gracilin" norditerpenes with extensively rearranged carbon skeletons [12], while specimens collected at Coffs Harbor or Sydney (both New South Wales) contained rearranged norditerpenes with a tetrahydroaplysulphurin, tyrinnal or gracilane skeleton [13].…”