Introduction Although the pathophysiological mechanism of hypertension is not fully elucidated yet, a large number of pieces of evidence have shown that genetic alterations in the renin-angiotensin-aldosterone system play a central role. However, the association of insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene with essential hypertension is controversial yet, and there is a limited number of publications among the Ethiopian population. Therefore, this study aimed to determine the association of ACE gene I/D polymorphism with the risk of hypertension among essential hypertension patients at the University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia. Materials and methods A case-control study was conducted from October 07, 2020, to June 02, 2021, among hypertensive patients and normotensive control groups at the University of Gondar Comprehensive Specialized Hospital. A structured questionnaire was used to collect socio-demographic data and anthropometric measurements. Five milliliters of blood were drawn from each of the randomly selected 64 hypertensive and 64 normotensive participants for molecular test analysis. Genetic polymorphism of the ACE gene was identified using polymerase chain reaction (PCR) and electrophoresis. Data analysis was done using SPSS version 25.0 software. The strength of association between the genotype and hypertension was estimated through the calculation of adjusted odds ratio and 95% confidence intervals using logistic regression. P-value < 0.05 was considered statistically significant. Result The distribution of DD genotypes and D allele of the ACE gene were 48.4% and 63% in essential hypertensive patients, respectively, while it were 29.7% and 42.2% in control subjects respectively. The ACE DD genotype (p-value = 0.005) and D allele (p-value = 0.001) were more frequent among hypertensive patients as compared to controls. Conclusion The present study found that the DD genotype and D allele of the ACE gene has had a strong association with a high risk of hypertension in the study population.

No abstract

No abstract

No abstract

Asymmetric alkynylation reactions to linear alkyl and substituted aromatic aldehydes have been accomplished in good yields and with a range of selectivities. For aromatic aldehydes we observed that the selectivity of the alkynylation reaction appears to depend upon the substituents on the aromatic ring. Thus with electron-withdrawing substituents both the yield and enantioselectivities were good to excellent. In contrast to this, the presence of electron-donating groups provided excellent conversions; however, these were coupled with poor enantioselectivities.In a recent paper 1 we revealed a diastereoselective cobaltmediated synthesis of benzopyrans using a novel variation of an intramolecular Nicholas 2 reaction in the key step. Using this chemistry we were able to access a number of functionalised benzopyran derivatives 2, which were then subsequently screened against cromakalim 3 3, a known modulator of potassium channels (Scheme 1).In our efforts to achieve an enantioselective Nicholas reaction 4 we have focussed upon the synthesis of optically active propargyl alcohols, based upon 1, for use in benzopyran synthesis. The ability to transfer the stereochemical information, contained within a dicobalt hexacarbonyl complexed chiral propargyl alcohol, into the resulting product still remains a challenge to the synthetic chemist. This limitation has been explained by the fluxional nature of a cobalt-stabilised carbocation that exposes both faces to the incoming nucleophile 5 thus leading to racemisation. One solution to this racemisation process lies in the ability to rapidly quench the cation before delocalisation effects take place. The first example of an enantiospecific Nicholas reaction, a process which provided chiral products from chiral substrates, was disseminated in 1994. 6 In the same year the rapid racemisation of a cobalt-stabilised cation was exploited to afford a stereoselective synthesis of fused-ring systems. 7 Chiral propargyl alcohols may be prepared via the asymmetric reduction of ynones 8 or from the asymmetric addition of alkynes to aromatic aldehydes. 9 Although the catalytic enantioselective addition reaction of dialkyl and alkenyl zinc reagents to aldehydes may be carried out efficiently, using a wide range of catalysts, advancements with the corresponding asymmetric alkynylation reaction appears to be far less developed. 10 The major limitations seem to be based upon a combination of factors such as the need to employ stoichiometric amounts of catalyst/ ligand, limitations in the availability of appropriate reagents such as chiral ligands and, in some examples, the production of significant quantities of by-products. 11From our inspection of the existing literature, in this interesting area of asymmetric synthesis, we were able to corroborate the inconsistencies in the percentage yields and/ or enantioselectivities for asymmetric alkynylation reactions. For instance with aldehydes such as 4 (Figure 1), with R = alkyl, good to excellent yields for the alkynylation reaction have been repor...