Reassignment of crispatene, isolation and chemical characterization of stachydrine, isolated from the marine mollusk Elysia crispata.

The molluscan genus Elysia Risso, 1818 (Sacoglossa) is composed of shell-less herbivore sea slugs. From these marine organisms, polyketides such as polypropynates have been isolated and showed cytotoxic, antibiotic, and antifungal, and antiviral properties. In this work, we reported the isolation, and structure elucidation of two compounds isolated from marine mollusk E. crispata. Both compounds isolated, crispatene (1) and stachydrine (2), were purified by HPLC. The chemical structure of compound (1) was reassigned through 1D and 2D NMR experiments and high-resolution electrospray ionization mass spectrometry (HRESIMS). On the other hand, this is the first time that compound (2) has been found in this species of mollusk or the marine environment, previously, (2) has only been found in terrestrial plants or bacteria in symbiosis with plants.

Synthesis and biological evaluation of ( - )-13,14-dihydroxy-8,11,13-podocarpatrien-7-one and derivatives from (+)-manool.

13,14-Dihydroxy-8,11,13-podocarpatrien-7-one (1) and a series of ring C aromatic diterpene derivatives were synthesised from (+)-manool (4) and evaluated for their cytotoxic, leishmanicidal and trypanocidal activities. Our results indicated that compound 1 and other podocarpane-type intermediates are cytotoxic. Cleavage of C6-C7 bond of compound 7 improved cytotoxic activity, indicating that, in particular, the 6,7-seco-podocarpane-type compound 20 might serve as a lead compound for further development.

Facile access to optically active ring C aromatic diterpene derivatives from (+)-manool. first synthesis of 13,14-dihydroxy8,11,13-podocarpatrien-7-one.

14,15,17-Trinorlabdan-8,13-dione 6 was efficiently synthesized via ozonolysis of(+)-manool (4) followed by treatment with aqueous NaOH in the presence of tetra-n-butylammonium bromide as catalyst. This protocol has the advantages of high yield, mild conditions and simple procedure. Utilizing this strategy, the first enantiospecific synthesis of 13,14-dihydroxy-8,11,13-podocarpatrien-7-one (1), a constituent of Taiwania cryptomerioides and Celastrus paniculatus, was achieved starting from (+)-manool (4) after a four-step sequence in 24% overall yield.

Photosensitizing properties of Actarit, an antirheumatic drug.

The photobiological properties of 4-acetylaminophenylacetic acid (Actarit, ACT, MS-932, CAS 18699-02-0) were studied using in vitro phototoxicity assays: photohemolysis, photoperoxidation of linoleic acid and Candida sp phototoxicity test. ACT reduced nitro blue tetrazolium (NBT) when irradiated with lambda > or = 300 nm in deoxygenated aqueous buffer solution (pH 7.4). The photohemolysis rate and photoperoxidation of linoleic acid were inhibited significantly by reduced glutathione. ACT was phototoxic to Candida sp. The isolation and identification of the photodegradation products of ACT in phosphate buffered saline solution (pH 7.4) and methanol were studied under aerobic conditions. Four compounds were identified and two of them isolated and characterized by spectroscopic methods. A photodecarboxylation with the participation of oxygen via a type I mechanism was proposed for the photodegradation of ACT which undergoes direct electron transfer from the excited state of ACT carboxylate and homolytic rupture of the alpha-carbon bond. A photodynamic mechanism involving radicals and electron transfer reactions was suggested for the observed in vitro phototoxicity.