4s-ferrugineone and 4s,5s-ferrugineol as pheromones of palm weevils were synthesized in 3 and 4 steps, respectively, starting from nonane-5-one employing samp-/ramp -hydrazone methodology. 5-nonanone is transformed to its corresponding ramp hydrazone by reaction with the enantiomerically pure hydrazine ramp. metalation with lithium diisopropylamide (lda) in ether to form azaenolate, followed by...

4S-ferrugineone and 4S,5S-ferrugineol as pheromones of palm weevils were synthesized in 3 and 4 steps, respectively, starting from nonane-5-one employing SAMP-/RAMP -hydrazone methodology. 5-nonanone is transformed to its corresponding RAMP hydrazone by reaction with the enantiomerically pure hydrazine RAMP. Metalation with lithium diisopropylamide (LDA) in ether to form azaenolate, followed by...

Reactions of the [3Fe-4S] cluster and various metallated [M3Fe-4S] adducts co-ordinated in the ferredoxin from the hyperthermophile Pyrococcus furiosus have been studied by protein-film voltammetry, bulk-solution voltammetry, solution kinetics and magnetic CD (MCD). The [3Fe-4S] cluster exhibits two couples, [3Fe-4S]+/0 and [3Fe-4S]0/2-. Film voltammetry is possible over a wide pH range (2-8), ...

We report a direct square-wave voltammetric study of the iron-sulfur enzyme, aconitase, at the pyrolytic graphite edge electrode. New and established redox driven reactions were observed and the equilibrium reduction potential for each couple was determined: E0'[3Fe-4S]1+/0 = -268 mV, E0'[4Fe-4S]2+/1+ = -450 mV, E0'[4Fe-4S]3+/2+ = +100 mV, E0'Linear Form = -281 mV, and putatively, E0'[3Fe-4S]0/...

Using a chemical isotope derivative method, we have determined the minor base composition of the "70S-associated" 4S RNA isolated from avian myeloblastosis virus. The minor base composition of this "70S-associated" 4S RNA is strikingly similar to that of the corresponding "free" 4S RNA of the virion. This minor base content, plus the capacity to esterify amino acids, establishes that both of th...

The universe of known biological FeS clusters is constantly enlarging. Besides the conventional, well described [2Fe–2S], [3Fe–4S] and cubane [4Fe–4S] clusters, novel, unprecedented structures are emerging. They include unusually coordinated with additional sulfur atoms, e.g., [4Fe–5S], [5Fe–5S], [4Fe–4S]-5S-[4Fe–4S], [8Fe–7S], [8Fe–9S] [8Fe–8S–C] heteronuclear [Ni–4Fe–4S], [2Ni–4Fe–4S], [4Fe–4...

Of 4-amino-5-chloro-2-methoxy-N-(1-ethyl-2-hydroxymethyl-4- pyrrolidinyl)benzamide, four optical isomers, (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, were prepared from optically active 4-amino-1-ethyl-2-hydroxymethylpyrrolidine di-p-toluenesulfonate [(2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, respectively]. The requisites, (2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-2...

Photoionization spectra of Se have been studied by step-wise resonance laser ionization. The Rydberg series 4s24p3(4S)np3P0,1,2 and 4s24p3(4S)np5P1,2,3 were measured via different excitation schemes. Using the 4s24p3(4S)np3P2 with n = 15–49, ionization potential was determined improved precision to 76,658.15(2)stat(4)sys cm?1, which resolved discrepancy in previous literatures. Autoionizing (AI...

In recent studies, an optically pumped Ar*/He laser has been demonstrated using the Ar 4p[1/2]1→4s[3/2]2 transition at 912.55 nm. Time-resolved data for this system, recorded using CW laser excitation and pulsed discharge production of Ar* 4p[3/2]2, yielded laser output pulses that were of unexpectedly short duration. It was speculated that radiative relaxation from the upper laser level to the...