was a Japanese
agricultural scientist
An agriculturist, agriculturalist, agrologist, or agronomist (abbreviated as agr.), is a professional in the science, practice, and management of agriculture and agribusiness. It is a regulated profession in Canada, India, the Philippines, the U ...
and
biochemist whose research focused on the components of
green tea. She was the first woman in Japan to receive a
doctoral degree
A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism ''l ...
in
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...
.
Early life
Tsujimura was born in 1888 in what is now Okegawa in
Saitama Prefecture. She attended Tokyo Prefecture Women's Normal School, graduating in 1909, and the Division of Biochemical Science at
Tokyo Women's Higher Normal School. There, she was taught by the biologist
Kono Yasui
was a Japanese biologist and cytologist. In 1927, she became the first Japanese woman to receive a doctoral degree in science. She received a Medal of Honor with Purple Ribbon and was awarded as an Order of the Precious Crown Third Class for he ...
, who inspired in Tsujimura an interest in scientific research. She graduated in 1913 and became a teacher at Yokohama High School for Women in
Kanagawa Prefecture
is a prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-densest at . Its geographic area of makes it fifth-smallest. Kanag ...
. In 1917, she returned to Saitama Prefecture to teach at Saitama Women's Normal School.
Career and research
Tsujimura's research career began in 1920 when she joined
Hokkaido Imperial University as a laboratory assistant. At the time, the university did not accept female students, so Tsujimura worked in an unpaid position at the Food Nutritional Laboratory of the university's Agricultural Chemistry Department. There, she researched the nutrition of
silkworms
The domestic silk moth (''Bombyx mori''), is an insect from the moth family Bombycidae. It is the closest relative of ''Bombyx mandarina'', the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically im ...
before transferring to the Medical Chemical Laboratory at the Medical College of
Tokyo Imperial University
, abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...
in 1922. The laboratory was destroyed in the
1923 Great Kantō earthquake in September, so she transferred to
RIKEN as a research student in October 1923. She worked in the laboratory of
Umetaro Suzuki
was a Japanese scientist, born in what is now part of Makinohara, Shizuoka, Japan. He was a member of the Imperial Academy, and a recipient of the Grand Cordon of the Order of the Sacred Treasure and the Order of Culture. His research was among t ...
, a doctor of agriculture, and researched nutritional chemistry. Tsujimura and her colleague Seitaro Miura discovered
vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...
in
green tea in 1924, and published an article titled "On Vitamin C in Green Tea" in the journal ''Bioscience, Biotechnology, and Biochemistry''.
[ This finding contributed to an increase in green tea exports to North America.][
In 1929, Tsujimura isolated the flavonoid ]catechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids.
The name of the catechin chemical family derives from ''catechu'', which is the tanni ...
from green tea. She extracted tannin
Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
The term ''tannin'' (from Anglo-Norman ''tanner'' ...
in crystal form from green tea in 1930. Her thesis on the constituents of green tea, titled "On the Chemical Components of Green Tea", earned her a doctorate in agriculture from Tokyo Imperial University in 1932, making her the first woman in Japan to receive such a degree.[ She went on to isolate ]gallocatechin
Gallocatechol or gallocatechin (GC) is a flavan-3-ol, a type of chemical compound including catechin, with the gallate residue being in an isomeric trans position.
This compound possesses two epimers. The most common, (+)-gallocatechin (GC), CAS ...
from green tea in 1934 and registered a patent on her method of extracting vitamin C crystals from plants in 1935. She was promoted to the role of junior researcher at RIKEN in 1942 and then researcher in 1947 before becoming a professor at Ochanomizu University
is a women's university in the Ōtsuka neighborhood of Bunkyō-ku, Tokyo, Japan.
Ochanomizu University is one of the top national universities in Japan.
Ochanomizu is the name of a Tokyo neighborhood where the university was founded.
Hi ...
when it was established in 1949. She was a professor at Tokyo Women's Higher Normal School from 1950 and was the school's first dean of the Faculty of Home Economics.[
]
Retirement, death, and legacy
Tsujimura retired from Ochanomizu University as a professor in 1955, but continued lecturing part-time until 1961. She was a professor at Jissen Women's University
is a Japanese private women's college with its headquarters in 4-1-1 Ōsakaue, Hino, Tokyo, Japan. The school was founded by poet and educator Utako Shimoda in 1899. It was chartered as a university in 1949. Its University abbreviations are ...
in Tokyo from 1955 to 1963, when she became a professor emeritus. She was awarded the Japan Prize of Agricultural Science in 1956 for her research on green tea and was conferred the Order of the Precious Crown of the Fourth Class in 1968. She died in Toyohashi
is a city in Aichi Prefecture, Japan. , the city had an estimated population of 377,453 in 160,516 households and a population density of 1,400 persons per km2. The total area of the city was . By area, Toyohashi was Aichi Prefecture's second-lar ...
on 1 June 1969 at the age of 80.[
Tsujimura's 133rd birthday was celebrated with a ]Google Doodle
A Google Doodle is a special, temporary alteration of the logo on Google's homepages intended to commemorate holidays, events, achievements, and notable historical figures. The first Google Doodle honored the 1998 edition of the long-running an ...
on September 16, 2021.
See also
*Timeline of women in science
This is a timeline of women in science, spanning from ancient history up to the 21st century. While the timeline primarily focuses on women involved with natural sciences such as astronomy, biology, chemistry and physics, it also includes women f ...
References
{{DEFAULTSORT:Tsujimura, Michiyo
1888 births
1969 deaths
Agriculturalists
Japanese agricultural scientists
Japanese biochemists
Ochanomizu University faculty
Women biochemists
Japanese women chemists
20th-century women scientists
Riken personnel
Vitamin researchers
20th-century Japanese chemists