Alfredo Toscano

Neo-clerodane-type diterpenoids from Salvia keerlii

Abstract From the aerial parts of Salvia keerlii two new neo-clerodane diterpenoids have been isolated. Their structures: 8,12( R )epoxyneo-cleroda-3,13(14)-diene-18,19:15,16-diolide, kerlin and 7-acetoxy-12( R )hydroxyneoclerodane-3,13(14)-diene-18,19:15,16-diolide, kerlinolide, have been established by spectroscopic means. X-ray diffraction analysis was performed for kerlin.

Tertiary stibines containing aromatic heterocycles and their silver complexes: synthesis and X-ray structures

Abstract The work presents the synthesis of tertiary stibines containing heterocyclic aromatic groups of general formula (2-C4H3X)3Sb where X=S (1), O (2) or NMe (3). These stibines were brominated to give corresponding dibromide and were complexed with silver(I) nitrate. The stibines, dibromides and their silver complexes were characterized by elemental analyses, IR, UV, mass, 1H, 13C, COSY, HETCOR NMR spectroscopy. Molecular structures of (2-C4H3S)3Sb (1); (2-C4H3S)3SbBr2 (4) and {Ag[(2-C4H3S)3Sb]2}NO3 (6) were determined by X-ray spectroscopy. This is the first X-ray crystallographic report on stibines containing heterocyclic aromatic groups and their silver complexes. The stibine (1) is pyramidal while its dibromide has trigonal bipyramidal structure. The silver complex (6) has a polymeric nature with NO3− acting as a bridging ligand.

Hydroxyclerodanes from Salvia shannoni

Six new hydroxyclerodanes (1-6), named sepulturins A-F, and four known diterpenes were isolated from the leaves of Salvia shannoni. The structures of these compounds were established by extensive analysis of their NMR and MS spectroscopic data. The relative configurations of compounds 1 and 2 were determined by NOESY experiments and were confirmed by single-crystal X-ray diffraction studies. All of the isolated diterpenes possess tertiary OH groups. The structure of infuscatin (7), a clerodane previously isolated from S. infuscata, was revised. Cytotoxic, antiprotozoal, and anti-inflammatory activities of these compounds were evaluated.

Structure of salvigenolide, a novel diterpenoid with a rearranged neo-clerodane skeleton from salviafulgens

Abstract From the aerial parts of Salvia fulgens Cav. (Labiatae) a new diterpenoid with a rearranged neo-clerodane skeleton was isolated. This novel compound named salvigenolide, showed a six-seven A/B ring system with a trans fussion. A probable biogenetic route is proposed. Its structure and relative stereochemistry as in 1 , were established by spectroscopic means and X-ray diffraction analysis.

Salviandulines A and B. Two secoclerodane diterpenoids from Salvia lavanduloides

Abstract Two novel 9,10-secoclerodane diterpenoids, salviandulines A and B, were isolated from aerial parts of Salvia lavanduloides . Their structures were established by high resolution NMR and X-ray diffraction analysis.

Synthesis and characterization of some arene hydrido-complexes [Ru(η6-arene)(EPh3)2H]+ (η6-arene=benzene, p-cymene or hexamethylbenzene; E=P, As or Sb). Crystal structure of [Ru(η6-C6H6)(PPh3)2H]BF4

[{Ru( η 6 -arene)Cl 2 } 2 ] ( η 6 -arene=benzene, p-cymene or hexamethylbenzene) reacts with EPh 3 (E=P, As or Sb) in methanol to give monomeric cationic arene hydrido complexes [Ru( η 6 -arene)(EPh 3 ) 2 H] + in presence of AgBF 4 or AgPF 6 . However, reactions in presence of triphenylphosphine also yield a symmetrically bridged tris ( μ -methoxy) complex [(PPh 3 ) 3 Ru( μ -OMe) 3 Ru(PPh 3 ) 3 ] + . The crystal structure of [Ru( η 6 -C 6 H 6 )(PPh 3 ) 2 H]BF 4 has been determined. Crystal data, monolinic system, space group P2 1/n , a =14.792 (2) A; b =14.351 (1) A; c =17.661 (2) A; β =102.25 (1)° and Z =4. Crystal structure determination reveals the distortion of the Ru(PPh 3 ) 2 H + unit in the cation [Ru( η 6 -C 6 H 6 )(PPh 3 ) 2 H] + .

Stereoselectivity of formation of polycyclic ferrocenyl-4,5-dihydropyrazoles based on E- and Z-s-cis-α,β-enones

Abstract Reaction of E- and Z-isomeric 2-ferrocenylmethylidene-1-tetralone, 2-ferrocenylmethylidene-3-quinuclidinone, 1-methyl-3-ferrocenylmethylidene-4-piperidone and 2-ferrocenylmethylidenetropinone with hydrazine proceeds stereospecifically with the formation of the same diastereomeric polycyclic ferrocenyldihydropyrazoles independently of the geometric configuration of the starting α,β-unsaturated ketones. X-ray structural analysis is presented for the trans-diastereomer of 4-acetyl-3-ferrocenyl-1,4,5-triazatricyclo[5.2.2.02,6]undec-5-ene.

Regioselectivity of alkylation of the naphthalene fragment in the opening of a small ring in 3-ferrocenyl-3-(1-naphthyl)cyclopropene, Z-2-bromo-1-ferrocenyl-1-(1-naphthyl)cyclopropane, and 1-ferrocenyl-1-(1-naphthyl)cyclopropane

Abstract The opening of a small ring in 3-ferrocenyl-3-(1-naphthyl)cyclopropene (thermolysis, action of HBF4·Et2O or CF3SO3H), Z-2-bromo-1-ferrocenyl-1-(1-naphthyl)cyclopropane (action of AlCl3), and in 1-ferrocenyl-1-(1-naphthyl)cyclopropane (action of Ph3C+BF4−) is accompanied by the alkylation of only the naphthalene fragment giving rise to 1-ferrocenyl-9bH-benzo[e]indene or 1-ferrocenyl-3H-benzo[e]indene. This is connected with a ‘non-bisecting’ position of the naphthalene fragment relative to the three-membered cycle in the starting compounds. The compound 1-ferrocenyl-9bH-benzo[e]indene gives [4+2]-cycloadducts with N-phenyl(azodicarboximide) and N-phenylmaleimide. X-ray structural data are presented for 3-ferrocenyl-3-(1-naphthyl)cyclopropene and its adduct with 1,3-diphenylisobenzofuran, Z-2-bromo-1-ferrocenyl-1-(1-naphthyl)cyclopropane, and 1-ferrocenyl-1-(1-naphthyl)cyclopropane.

The anticoagulant effect of prolame, N-(3-hydroxy-1,3,5(10) estratrien-17β-yl)-3-hydroxypropylamine, a novel amino-estrogen

The anticoagulant and estrogenic effects of prolame, N-(3-hydroxy-1,3,5(10)-estratrien-17 beta-yl)-3-hydroxypropylamine, are described. A single subcutaneous injection of prolame in male mice, ovariectomized mice, adult and infant male rats, produced dose-dependent increases of blood clotting time, which could be observed with the larger doses even after 4 days. In ovariectomized mice, prolame produced vaginal cornifications of shorter duration than those produced by estradiol-17 beta. The evidence suggests that, in contrast with currently used estrogens, prolame would not generate cardiovascular accidents if used for the treatment of prostatic carcinoma; it could also be exceptionally effective for the prevention of thrombosis.

Lasianthin, a neo-clerodane diterpenoid from Salvia lasiantha

Abstract From the aerial part of Salvia lasiantha a neo-clerodane diterpenoid, lasianthin, was isolated. The structure of this compound was established by spectroscopic means and X-ray diffraction analysis.