Subject guanidinium

The complex formed by thymine with the guanidinium ion (Figs. 6.7, 6.8) and the complex formed by thymine with the aminopyrolidinium ion (Figs. 6.9,6.10) were subjected to ab initio (Hartree-Fock) calculations using the 6-31G find the 3-21G basis sets, in order to... 

Fig. 1. SDS-PAGE pattern of human IgG heavy chain eluted from PVDF membrane. Human IgG (10 pg) was resolved by SDS-PAGE and transferred to a PVDF membrane. The proteins on the membrane were stained with amido black in water, and the heavy chain was excised and eluted with guanidinium hydrochloride/lysophosphatidylcholine. After precipitation with absolute alcohol, the glycoprotein was subjected to analytical SDS-PAGE, and the gel was stained with Coomassie brilliant blue to ascertain its purity. Lanes 1 and 4 original commercial preparation of human IgG lanes 2 and 3 IgG heavy chain eluted from the PVDF membrane lane 5 mixture of molecular mass standards, from top to bottom phosphorylase b (94 kDa), BSA (67 kDa), ovalbumin (43 kDa), carbonic anhydrase (30 kDa), soybean trypsin inhibitor (20 ldDa), ct-lactalbumin (14.4 kDa).

Henry and Besser (Ref) report that the salt is less effective as a propint burning rate booster than the parent acid, although it still yields faster burning pro pints than similar formulations using Nitroguanidine. The cool proplnt formulation used as an evaluation vehicle consisted of NC (29.84), NG (7.86), l-ethyl-5-ethylamino-tetrazole (7.50), and the subject salt (54.80%) Ref R.A. Henry E.D. Besser, Preparation and Preliminary Evaluation of 1 -(5-Tetrazolyl)-2-Nitroguanidine and its Guanidinium Salt , NAVORD 3483 (1955)... 

As concerns the molecular size and shape, the (protonated) guanidine and urea are rather similar moreover, they are isoelectronic. However, guanidine is much more basic, pKa being 13.6 compared with 0.1 for urea, so that it is not surprising that more readily available guanidinium was subjected to systematic study earlier. 

Fig. lA-D. Immunofractionation of chromatin digested by micrococcal nuclease for various extents of time on an anti-poly(ADP-ribose) Sepharose column. HeLa nuclei from 10 cells were digested with micrococcal nuclease [50 units/10 nuclei at 37°C for 1 min (A), 5 min (B), 10 min (C), and 20 min (D)]. Soluble chromatin was subsequently prepared and immunofractionated on an anti-poly(ADP-ribose) Sepharose column. The columns were loaded and washed with phosphate buffered saline. Transmittance at 254 nm was continuously monitored. When no further UV-absorbing material was eluted, 6 M guanidinium hydrochloride was added to elute-bound material. The insets in each panel represent 1/50 of the DNA extracted from the pooled unbound U) and bound (B) peak fractions subjected to electrophoresis on 1.5% agarose. The gel was stained with ethidium bromide. (Taken from [10])... 

Based on catalytic double activation (guanidinium salt/thiourea moiety skeleton), Nagasawa et al. were able to achieve the reaction of nitromethane, nitro-ethane, and nitropropane with aliphatic a-ketoesters in moderate yields and selectivities (Scheme 29.10) [24]. The reaction works with the assistance of 10 mol% KOH and to overcome the retro-nitroaldol reaction, the presence of 50mol% K1 was required. The resulting Henry reaction adducts are obtained with good syn/anti ratios, and enantioselectivities of up to 98%. When aromatic a-ketoesters were subjected to the reaction unsatisfactory results were obtained (e.g., R = Ph, 5% yield and 5% ee). 

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