Géza Gusztáv Zemplén, Ph.D. (26 October 1883 – 24 July 1956) was a notable Hungarian chemist,

organic chemist Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

, professor, and chemistry author. He was a recipient of the

Kossuth Prize The Kossuth Prize (, ) is a state-sponsored award in Hungary, named after the Hungarian politician and revolutionist Lajos Kossuth. The Prize was established in 1936, by the Hungarian National Assembly, to acknowledge outstanding personal and grou ...

, a member of the

Hungarian Academy of Sciences The Hungarian Academy of Sciences ( , MTA) is Hungary’s foremost and most prestigious learned society. Its headquarters are located along the banks of the Danube in Budapest, between Széchenyi rakpart and Akadémia utca. The Academy's primar ...

, and was the brother of Professor Győző Zemplén. His major field of research was structural chemistry and biochemistry including the synthesis of naturally occurring flavonoid-glycosides (isolated from plants).

Life

Géza Zemplén was born in Trencsén, the son of János Zemplén and Janka Vittlin, both

Roman Catholic The Catholic Church (), also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institut ...

s. After having completed his secondary education in

Fiume Rijeka (; Fiume ( �fjuːme in Italian and in Fiuman Venetian) is the principal seaport and the third-largest city in Croatia. It is located in Primorje-Gorski Kotar County on Kvarner Bay, an inlet of the Adriatic Sea and in 2021 had a po ...

, he enrolled in the Eötvös College Budapest in 1900. During his studies he produced two prize-winning works in the sciences. In 1904 he obtained a Ph.D. (doctor rerum naturalium). After having completed his probationary year of teaching, he became a certificated teacher. He then joined the faculty of the College of Mining and Forestry in Selmecbánya in 1905. One year later he was promoted to the post of adjunct professor. He married Margit Heinrich Johanna Friderika (the Roman Catholic daughter of János Heinrich and Emilia Turnovszky) in 1907 in Budapest. However, they were divorced in 1920. In order to gain further expertise in organic chemistry Zemplén left for

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

where he worked for 2.5 years for the renowned professor

Emil Fischer Hermann Emil Louis Fischer (; 9 October 1852 – 15 July 1919) was a German chemist and List of Nobel laureates in Chemistry, 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fisch ...

, first as an assistant and later (on Fischer's invitation) as a colleague in his private laboratory. On the invitation of

Emil Abderhalden Emil Abderhalden (9 March 1877 – 5 August 1950) was a Swiss biochemist and physiologist. His main findings, though disputed already in the 1910s, were not finally rejected until the late 1990s. Whether his misleading findings were based on fra ...

, an eminent biochemist, Zemplén participated in the writing of ''Biochemisches Hand-lexikon'' and also ''Handbuch der biochemischen Arbeitsmethoden''. In 1910 Zemplén returned to his job in Selmecbánya where he was presented the Hungarian Journal of Chemistry Award as well as the Hungarian National Society of Forestry Award. In 1912 he was qualified by the University of Budapest as doctor habil, and in 1913 he was appointed the Head of the newly created Department of Organic Chemistry of the Palatine Joseph Technical University. Beginning in 19l4, he acted as the councilor of the Budapest's Chinoin Pharmaceutical Factory. In Budapest, on 12 February 1920, Professor Zemplén married the

Calvinist Reformed Christianity, also called Calvinism, is a major branch of Protestantism that began during the 16th-century Protestant Reformation. In the modern day, it is largely represented by the Continental Reformed Protestantism, Continenta ...

Natália Endrédy, the daughter of Károly Endrédy and Irma Helfy. Natália died only a few years later. In 1927 he was elected corresponding member and later, in 1928, a member of the

. The same year he was awarded the Hungarian Academy's Grand Prix, which at that time was the highest national recognition a Hungarian scholar could achieve. In 1932 Dr. Zemplén received the Corvin chain (a national award founded in remembrance of King Mátyás Hunyadi) in recognition of his activity abroad as well as in Hungary. On 14 October 1933 Professor Zemplén married the

Karolina Sarolta Rau (born in 1902, parents: András Ernő Rau and Irén Róza Kovács). The wedding was held in the Erzsébet district of Pest. Between 1930 and 1940 Zemplén continued research on the naturally occurring flavonoid-glycosides and succeeded in elucidating the

structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

of several of them, as well as accomplishing their total syntheses. His research contributed to the industrial isolation and application of

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s found in plants. In 1941 he was invited to give a lecture in Germany. During the course of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

he continued his research although his institute was almost entirely ruined due to the

Siege of Budapest The siege of Budapest or battle of Budapest was the 50-day-long encirclement by Soviet and Romanian forces of the Hungarian capital of Budapest, near the end of World War II. Part of the broader Budapest Offensive, the siege began when Budapes ...

. In 1947,

Georgetown University Georgetown University is a private university, private Jesuit research university in Washington, D.C., United States. Founded by Bishop John Carroll (archbishop of Baltimore), John Carroll in 1789, it is the oldest Catholic higher education, Ca ...

in Washington invited Zemplén as guest professor for one year. Toward the end of his stay in the USA he fell ill with cancer. In Hungary he was among the first to receive the golden level of the

. He also became a member of the Presidium of the Scientific Council. Professor Zemplén is the author of more than 200 scientific publications and a textbook entitled ''Szerveskémia'' ("Organic Chemistry"). He died in

Budapest Budapest is the Capital city, capital and List of cities and towns of Hungary, most populous city of Hungary. It is the List of cities in the European Union by population within city limits, tenth-largest city in the European Union by popul ...

on 24 July 1956. Zemplén's publications can be found in numerous German and Hungarian chemical journals including the ''Berichte der Deutschen Chemischen Gesellschaft'' (German), the ''Zeitschrift für physiologische Chemie'' (German), the ''Zentralblatt für Physiologie'' (German), ''Vegyészeti Lapok'' (Hungarian), in ''Erdészeti Lapok'' (Hungarian), in ''Urania'' (German), and in the ''Jahresberichte über Gärungschemie und Gärungsorganismen'' (German). He had also written articles in ''Biochemisches Handlexikon'' on

dextrin Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch and glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α-(1→4) or α-(1→6) glycosidic bonds. Dextrins can be produced fro ...

inulin Inulins are a group of naturally occurring polysaccharides produced by many types of plants, industrially most often extracted from chicory. The inulins belong to a class of dietary fibers known as fructans. Inulin is used by some plants as a ...

alanine Alanine (symbol Ala or A), or α-alanine, is an α-amino acid that is used in the biosynthesis of proteins. It contains an amine group and a carboxylic acid group, both attached to the central carbon atom which also carries a methyl group sid ...

leucine Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α-Car ...

histidine Histidine (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an Amine, α-amino group (which is in the protonated –NH3+ form under Physiological condition, biological conditions), a carboxylic ...

proline Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the p ...

, oxyproline, and indol, as well as various

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diet ...

es,

cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

-containing

carbohydrate A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...

sulphur Sulfur (American spelling and the preferred IUPAC name) or sulphur (English in the Commonwealth of Nations, Commonwealth spelling) is a chemical element; it has Symbol (chemistry), symbol S and atomic number 16. It is abundance of the chemical ...

-containing

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s, indol-derivatives, and

s. In the ''Handbuch der biochemischen Arbeitsmethoden (1912-1913)'', Zemplén wrote about the production and detection of

glucoside A glucoside is a glycoside that is chemically derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes. Th ...

s as well as other, higher

s. Professor Zemplén acted as a referee of several journals in chemistry. A reaction type (

transesterification Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. Strong acids catalyze the r ...

s among

derivatives) was named after Zemplén.

Select publications and works

* "Vizes oldatok felületi feszültségéről" (Budapest, 1904; Doctoral thesis) * "Vizes oldatok felületi feszültségéről" (Budapest, 1907; published in ''Math. és Term. Értesítő'', the ''M. Chemiai folyóirat'' and the ''Annalen der Physik'') * "A kaliumpermanganat hatása a czellulózéra" (Budapest, 1907; ''Math. és Term. Ért.'') * "Erdei fák leveleinek nitrogén tartalmáról" (Budapest. 1908; ''Math. és Term. Ért.'') * "Verhalten der Cellobiose u. ihres Osons gegen einige Enzyme" (with

; Berlin, 1909–10; ''Liebig's Annalen'', and ''M. Ch. folyóirat'' 1909) * "Synthese der inaktiven α,δ-Diamino valleriansäure und des Prolnis" (with

; Budapest, 1909; ''Berichte der deutschen Chemischen Gesellschaft'', and ''M. Chem. Folyóirat'' 1909) * "Fából készített czukor és alkohol" (Budapest, 1910) * "Synthese der beiden optisch aktiven Proline" (with

; Budapest, 1910; ''Berichte der deutschen Chemischen Gesellschaft'', ''M. Chem. Folyóirat'' 1911) * "Neue Synthese von Amino-oxysäuren u. von Piperidon-Derivaten" (with

; Budapest, 1910; ''Berichte der deutschen Chemischen Gesellschaft'') * "Übers-Amino α-guanido-capronsäure" (with

; Budapest, 1910; ''Berichte der deutschen Chemischen Gesellschaft'') * "Nachhang" to "Übers-Amino α-guanido-capronsäure" (Budapest) * "Einige Derivate der Cellobiose" (with

; Budapest, 1911; ''Berichte der deutschen Chemischen Gesellschaft'') * "Studien über die Polysaccharide spaltenden Fermente in Pilzpressaften" (with Hans Pringsheim; Budapest, 1909; ''Zeitschrift für physiologische Chemie'') * "Az ureáz ipari alkalmazását czélozó kísérletek" (Budapest, 1912; ''Vegyészeti Lapok'', and ''Z. für angewandte Chemie'' 1912) * "Über die Verbreitung der Urease bei höheren Pflanzen" (Berlin, 1912; ''Z. für physiol. Chemie'') * "Beiträge zur chemischen Zusammensetzung der Korksubstanz" (Berlin, 1913; ''Z. für phyxiol. Chemie'', and ''Erdészeti Kísérletek'' 1913) * "Beiträge zur partiellen Hydrolyse der Cellulose" (Berlin, 1913; ''Z. für Phyziol Chemie'', and ''Erdészeti Kisérletek'' 1913) * "Uber die Gentiobiose" (Berlin, 1913; ''Z. für Phyziol Chemie'') * "Verhalten des Emulsins in Gegenwart von Pyridin" (Berlin, 1913; ''Z. für Phyziol Chemie'') * "Szerves kémia" (1952)

References

*Szinnyei, József.
Magyar írók élete és munkái - Zemplén Géza
. (Lives and works of Hungarian Authors - Zemplén Géza). Budapest: Hornyánszky. 1891–1914.

*https://web.archive.org/web/20160304234133/http://www.humboldt.hu/HN22/HL3.pdf {{DEFAULTSORT:Zemplen, Geza 1883 births 1956 deaths Hungarian chemists Members of the Hungarian Academy of Sciences