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RESEARCH

A brief resume, with selected examples,

over 30 years of research in Organic Synthesis and Natural Products Chemistry from the Lobo-Prabhakar Group.

SYNTHESIZED MOLECULES | ISOLATED COMPOUNDS | PATENTS | SYNTHETIC METHODS | THEORETICAL CHEMISTRY

SYNTHESIZED MOLECULES

2003

Benzazepinones

diltiazem-related Ca²⁺ antagonists (antiarrhythmic)

Benzoxazinones

potent insecticides in gramineous plants

Benzimidazolones 

activators of chloride secretion: potential therapeutics for Cystic Fibrosis and Chronic Obstructive Pulmonary Disease

Benzazocinones 

Oxindoles and Pyrazolones

(+/-)-Eseroline

(-)-eseroline is the major metabolite of

(-)-physostigmine and possess an analgesic effect similar to that of morphine  

Calabar beans

(physostigma venenosum seeds)

(Flustra foliacea - marine bryozoan, aquatic colonial animal)

Tryprostatin B

cell-cycle progression inhibitor of tsFT210 (a mutant cell line deficient in Cdc2 kinase) at the G2/M phase barrier

(Aspergillus fumigatus)

Diisocyanate, Diurethanes and Diureides

prepared from dehydroabietic acid,

(dehydrogenation of rosin or abietic acid) can be used as industrial monomers for polimer production

colophony (rosin)

Ismine

Vasconine and Oxoassoanine

Arcyriaflavin-A

inhibition of protein kinase C, platelet aggregation  and citotoxic activity

Benzimidazolinones

activate 

cystic fibrosis transmembrane conductance regulator  

(CFTR)

Hippadine

antitumour, antiviral and anticholinergic activities

(Amaryllidacea family - crinum spp)

Cardenolides Sulphates

Cardiotonic steroids

(Papaver Rhoeas)

Cardenolides 

Cardiotonic steroids 

allosteric inhibitors of Na⁺,K⁺-ATPase

(slide: Dr. Kelly Moule)

ISOLATED COMPOUNDS

(Phellinus pini)

(Euphorbia piscatoria Ait.)

Triterpenoids

(Euphorbia peplus)

Euferol

and Melliferol 

(Euphorbia mellifera)

(Salvia Candelabrum)

(Pisolithus tinctorius)

PATENTS

Fases Estacionarias Quirais Baseadas em Terpenoides

PT 102878, 28-11-02

Diisocyanates, Diurethanes and Diureides from Abietic Acid

EP 92670001.4, 11-2-92

Processos para a Obtencao de Novos Derivados de Acidos Resinicos: Diisocianatos, Diuretanos e Diureidos

PT 96748, 11-2-91

Processo para Obtencao de Derivados de Acido Abietico e Composicoes Antimicrobianas desses Derivados

PT 85433, 28-7-87

DEVELOPED SYNTHETIC METHODS

Chemoselective O-desilylation 

using SbCl₅–wet acetonitrile

A new efficient method for deprotection of TBDMS derivatives of phenols, primary alcohols, carboxylic acids and secondary amines, consisting of SbCl₅ and MeCN with 0.1% water (w/v). It effects inter alia desilylation of a CH₂OTBDMS group in the presence of a ketal function.

Synthesis of Aziridines 

using Palladium(II) and Bromamine T

The palladium(II)-promoted reaction of a variety of olefins and bromamine T, as the nitrogen atom transfer reagent, provide N-tosyl-2-substituted aziridines under mild conditions.

Synthesis of Benzimidazole Derivatives  

from 1-Aza-1´,3´-Diaza-3,3´-Sigmatropic Rearrangements 

Enantioselective Synthesis of N-Arylaziridines 

by Phase-Transfer Catalysis

Synthesis of N-Aryl and N-Alkyl-O-Methyl Hydroxylamines

Trifluoroaceto or p-nitrobenzo-N-substituted hydroxamic acids are smoothly methylated with diazomethane and the products cleanly cleaved by hydrazine.

3,3-Sigmatropic Rearrangements

using Enehydroxylamines

Synthesis of Aziridines 

using N-Hydroxy-N-pivaloylanilines

Synthesis of Aminonitrones 

from Hydroxylamines and Ethyl Cyanoformate

Synthesis 3-Substituted N-Benzoyl Oxindoles 

using N-Aryl-O-Acyl Hydroxamic Acids

Selective O-Acylation of Aromatic Hydroxylamines 

using 2-Acyl Thiazolium Salts

THEORETICAL CHEMISTRY

The CIP System:

eliminating ambiguity in the comparison of

diastereomorphic and enantiomorphic ligands

Implementation of the Cahn-Ingold-Prelog System for Stereochemical Perception 

in the LHASA Program

The CIP Sequence Rules: 

Analysis and Proposal for a Revision