New Minor Diterpenoid Diacylglycerols from the Skin of the Nudibranch <i>Anisodoris fontaini</i>

The Patagonian dorid nudibranch Anisodoris fontaini contains in its mantle a series of isocopalane diterpenoid diacylglycerols. Five new minor metabolites, anisodorins 1−5 (1−5), along with the already reported 6 and 7, have been isolated and chemically characterized. The structure and the relative stereochemistries have been determined by spectroscopic means, while the absolute stereochemistries for 2−5 are suggested to be the same as for the biogenetically related major compounds 6 and 7. Synthesis of the enantiomer (8) of anisodorin 1 confirmed the proposed structure and absolute stereochemistry

Formal synthesis of ( − )-pereniporin B and ( − )-cinnamosmolide

<div><p>The paper describes a new pathway for an efficient synthesis of natural and bioactive drimanic compounds ( − )-pereniporin B (<b>1</b>) and ( − )-cinnamosmolide (<b>2</b>) from ketodiol <b>7</b>, an intermediate obtained before from accessible labdane diterpenoid (+)-larixol (<b>3</b>). The key step involves allylic bromination of acetate <b>8</b> with <i>N</i>-bromosuccinimide. The <i>in vitro</i> antimicrobial and antifungal activities of all compounds are also reported. Their structures were confirmed by both spectroscopic data and chemical transformations.</p></div

Synthesis, structural elucidation and biological evaluations of new guanidine-containing terpenoids as anticancer agents

Using sclareol and sclareolide as starting materials, the guanidine derivatives of 12-amino-11-dihomodrimane-8α-ol and 13-amino-14,15-bis-dinorlabd-8(9)-ene were synthesized by the reaction of the corresponding amines with sodium hydrogencyanamide in ethanol – water solution. Monoacyl- and diacylguanidines were prepared from activated with N,N-carbonyldiimidazole Δ8,9-bicyclohomofarnesenoic acid by the reaction with guanidine. Their structures were confirmed by the 1H and 13C NMR, IR spectral and elemental analysis data. The compounds 12, 13 and 15 were screened for their antiproliferative and cytotoxicity activities against Colo 205, Colo 320 and MRC 5 human lung fibroblasts with respect to standard drug, Cisplatin. The compounds 12 and 15 exhibits excellent results than positive control. Hence these two compounds may be act as drug lead molecules in cancer chemotherapy. </p