Stereo Chemistry Explain the Activity Toxicity and the Pharmacological Action  of Many Drugs

Rezk Ayad

doi:10.36648/0976-8505/13.6.001

Stereo Chemistry Explain the Activity Toxicity and the Pharmacological Action of Many Drugs

Rezk Ayad^*

Department of Pharmaceutical Chemistry, Al-Azhar University, Cairo, Egypt

*Corresponding Author:: Rezk Ayad
Department of Pharmaceutical Chemistry, Al-Azhar University, Cairo, Egypt
Tel: 01225432266
E-mail: rezek_ayad@yahoo.com

Received Date:March 23, 2022, Manuscript No. IPDCS-22-12301; Editor assigned date: March 25, 2022, PreQC No. IPDCS-22-12301 (PQ); Reviewed date: April 08, 2022, QC No. IPDCS-22-12301; Revised date: May 23, 2022, Manuscript No. IPDCS-22-12301 (R); Published date: June 01, 2022, DOI: 10.36648/0976-8505/13.6.001

Citation: Rezk A (2022) Stereo Chemistry Explain the Activity, Toxicity and the Pharmacological Action of Many Drugs. Der Chem Sin Vol:13 No:6

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Abstract

Many drugs differ in pharmacological action according to their stereochemistry. The quinine used as antimalarial while quinidine used as antiarrhythmic, dextro cyclophosphamide is toxic while the levo is anticancer, dextro ketamine used as general anathesia while levo ketamine is agitation agent, dextro secobarbital is anticonvulsant while levo secobarbital is anesthetic, levodopa is antiparkinsonism while dopa is a granulocytosis, levamisole is safe anthelmintic while tetramisole has many side effects and less active, Thalidomide the (R) form more safe than (S) form which is tratogenic, the cisplatin is more active than the trans form, the levo adrenaline is more active than dextro form the diethylstilbosterol the transform is more active than cis form.

Keywords

Stereochemistry; Levo; Dextro; Cis; Trans; Active; Inactive

Introduction

In 1948, Luis pastier reveals the expression of stereochemistry and explains what is chiral carbon when he presents the tartaric acid in two forms where the two forms differ in their crystals. Nearly most of the drugs which used in medicine are having chiral carbon(s) [1-5]. All natural amino acids are levo form and all natural sugars are dextro form. The expression of stereo isomer mean enantiomer means disassymetry. The Chirality means handedness also the chiral carbon equal stereo genic carbon which mean chiral center. (I.e. the chiral center may be sulfur, phosphorus or nitrogen instead of carbon). Enantiomer mean optical isomer which either levo or dextro [6-9]. The (R) form (Rectus) mean deviate the polarized light with clockwise while the (S) form sinister mean deviate the polarized light against clockwise (anti clockwise) [10]. Diastereomers mean the molecule has to chiral carbon. Eutomer main bioactive enantiomer i.e. having higher biological activity. Enantio selectivity means enzymes antibodies or receptors having selective bind to the compounds (used in enzyme assay) [11-18]. Homochirality mean there are many compounds having the same chiral carbon e.g. amino acids. Chiral switch mean racemic. The eutomer is versus diastomer where the eutomer is highly biological active while the diastomer is less active. Many drugs which used in medicine having carbonyl groups which when reduced by reductase enzyme in the body make it have chiral carbon, The compounds which contain benzene ring having stereochemistry due to it have double bond. Mostly drugs having stereochemistry which make them active compounds e.g. phthalazine, quinazoline, quinoxaline and benzimidazole derivatives [19-25].

Literature Review

Quinine

Quinine is a natural alkaloid obtained from cinchona bark used in treatment of malarial disease [26].

Quinine is levo form.

Quinidine

Quinidine also natural alkaloid obtained from cinchona bark from cinchona bark and used in the treatment of arrhythmia [27-29].

equation

Quinidine is dextro form.

Cyclophosphamide

Cyclophosphamide (cytophosphane) is anticancer agent used I treatment lymphoma, breast cancer, lung cancer…. etc. [30,31].

equation

The levo form of cyclophosphamide is more safe than dextro form of which is more toxic [32].

Ketamine

Ketamine is a general anesthetic drug when the drug in dextro form whiles the ketamine in levo form is agitating agent (hallucination) (agitate the patient) [33-38].

equation

Secobarbital

Secobarbital is a member of barbiturates which used as anticonvulsant when it is in dextro for. While the levo form of secobarbital used as general anesthetic agent [39-41].

equation

Levodopa

Levodopa (L-Dopa) is the antiparkinsonism when is in levo form which convert into dopamine in the brain.

The dextro form is a granulocytosis and not a cross the blood brain barrier. But the levo form a cross the blood brain barrier because it’s similar to amino acids [42-45].

equation

Levamisole

Levamisole is the levo form of tetramisole Which used as anthelmentic agent where the first used was racemic mixture which cause abdominal pain ( mainly due to the dextro form) [46-48].

equation

Thalidomide

Thalidomide theoritically only the inactive S (-) isomer is tratogenic but practically both isomers geno toxic because of its in vivo interconvertion and of its species dependants [49-51].

equation

The S isomer in cotrast to the R isomer has been linked to thalidomide tratogenic effects. N.B. the R isomer have not solved the problem of tratogenicity so the tratogenicity due to the numerous chiral and a chiral metabolites of which pharmacologocal and toxocological studies which remain very scarce [52].

Cisplatin

equation Cisplatin is anticancer agent which more active than transforms [53].

Levoadrenaline

Levoadrenaline synthesised by adrenalmedulla which synthesis it from tyrosine (amino acid) [54].

equation

The levo adrenaline is more active than dextro adrenaline.

The (S) (+) form is more than 100 fold potent as selective serotonine reuptake inhebetor than (R.) (-) isomer [55].

equation

Mithadone

Mithadone is analgesic which acts centrally with high affinity for opioid receptors, has been used to treat dependence resulted from opiate and used to treat the cancer pain. Mithadone is a chiral synthetic compound used in therapy under recemic mixture in humans R (-) mithadone is about (25-50) times more potent as an analgesic than its S (+) antipode [56-59].

equation

Discussion

All drugs which used medicine must be we know if these compounds have chiral carbon or have any form of stereochemistry of them. This knowledge explain and sharing in mechanisms, binding with receptors, pharmacological action. So must be study the stereochemistry in drug design.

Conclusion

The stereochemistry is important for explain the stereo of the compounds which used in medicine for treatment diseases where there is some isomeres (enantumers) may be uneffected, toxic or reveal some undesiraple effects which increase the diseases or suffer from the side effects.