Cytotoxicity of abietane diterpenoids from Perovskia abrotanoides and of their semisynthetic analogues

Syntheses of Carnosic Acid and Carnosol, Anti-oxidants in Rosemary, from Pisiferic Acid, the Major Constituent of Sawara

“…The other anti-oxidant diterpenes of rosemary, rosmanol and isorosmanol, have previously been synthesized from carnosic acid. 14,15) Synthetic carnosic acid showed potent antibacterial activities against Propionibacterium acnes and Staphylococcus aureus ME/GM/TC Resistant. Thus, these syntheses provide efficient methods to synthesize the anti-oxidant diterpenes of rosemary and these syntheses also demonstrate the utility of Sawara as a natural resource.…”

“…The other rosemary anti-oxidants, e.g., carnosol 3, rosmanol 4, and other antioxidant diterpenes were synthesized from carnosic acid 2. 14,15) This method will thus be applicable for the synthesis of these anti-oxidant diterpenes of rosemary. The potent antimicrobial activities (MIC, mg/ml) of carnosic acid and carnosol against Propionibacterium acnes (ATCC 6919) and Staphylococcus aureus ME/GM/TC resistant (ATCC 33592) were measured to show the potency of the antimicrobial compounds.…”

Semisynthesis of Isetexane Diterpenoid Analogues and Their Cytotoxic Activity

“…In our previous SAR study of carnosic acid analogues, 2) we found that among the carnosic acid analogues tested, the cytotoxic activity of the mother catechols tended to decrease when the phenolic hydroxy groups were acetylated or methylated, and that the activity of catechol often increased when the phenolic hydroxy groups were converted to an o-quinone system on C-ring. Our present studies on demethylsalvicanol series showed that, as in the case of carnosic acid series, the activity tended to decrease when the hydroxyls on C-ring were acetylated or methylated (1 vs. 2-5).…”

“…There are two papers which refer to the cytotoxic activity of demethylsalvicanol analogues. 2,3) Therefore, in the present paper, we report synthesis of demethylsalvicanol analogues, evaluation of their cytotoxic activity against P388 murine leukemia cells, and their structure and cytotoxic activity relationships (SAR) studies. Microwave-assisted biomimetic synthesis of brussonol (8) is also described.…”

Cytotoxic‐Antineoplastic Derivatives of Prenyl‐1,2‐naphthohydroquinone

“…Thus, the diacetylated Diels-Alder product 2a was prepared by the reaction of a-myrcene with 1,2-benzoquinone generated in situ by oxidation of catechol with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) [13] or sodium periodate (NaIO 4 ) [26 -27], followed by acetylation with acetic anhydride (Ac 2 O) in pyridine (Pyr). The intermediate diacetate 2a was chemically modified by epoxidation with m-chloroperbenzoic acid (MCPBA) to obtain compound 2b.…”