Hedyotis is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Rubiaceae

Rubiaceae

The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...

. Many species of this genus such as Hedyotis biflora, H. corymbosa and H. diffusa are well known medicinal plants. The hedyotis is native

Indigenous (ecology)

In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...

 to tropical and subtropical Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 and to islands of the northwest Pacific

Pacific Islands

The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....

. It comprises about 115 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

. The type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 for the genus is Hedyotis fruticosa.

Hedyotis was named

Botanical name

A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature and, if it concerns a plant cultigen, the additional cultivar and/or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants...

 by Linnaeus in 1753 in Species Plantarum

Species Plantarum

Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...

. This generic name is derived

Etymology

Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

 from two Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 words, hedys, "sweet", and otos, "ear", in reference to the sweet-scented, ear-shaped leaves of some species.

Hedyotis was formerly defined very broadly by some authors, and included species now placed in Oldenlandia

Oldenlandia

Oldenlandia is a genus of flowering plants in the family Rubiaceae. It is pantropical in distribution and has about 240 species. The type species for the genus is Oldenlandia corymbosa....

, Oldenlandiopsis

Oldenlandiopsis

Oldenlandiopsis is a genus of flowering plants in the family Rubiaceae. It is monospecific, comprising only one species, Oldenlandiopsis callitrichoides. This species had previously been placed in Hedyotis or in Oldenlandia. It is native to the West Indies, southern Mexico, and Central America...

, Houstonia

Houstonia

* Houstonia, Missouri is a city in Missouri* Houstonia is a genus of flowering plants, belonging to the madder family...

, Kadua

Kadua

Kadua is a genus of flowering plants in the family Rubiaceae. It comprises 29 species, all restricted to Polynesia. Twenty-two of these are endemic to the Hawaiian Islands. Some of the species are common at high elevation. Others are single-island endemics or very rare, and a few are probably...

, and other genera. It is now circumscribed

Circumscription (taxonomy)

In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....

 more narrowly, as a monophyletic group

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 that is closely related

Phylogenetic tree

A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...

 to Agathisanthemum

Agathisanthemum

Agathisanthemum is a genus of flowering plants in the Rubiaceae family. It was described by Johann Friedrich Klotzsch in 1861. It is found in tropical and southern Africa, on the Comoros and in Madagascar.-Species:* Agathisanthemum assimile Bremek....

.

Species include:

• Hedyotis acuminata
• Hedyotis cookiana
• Hedyotis coriacea
• Hedyotis degeneri
• Hedyotis diffusa
  Hedyotis diffusa
  Hedyotis diffusa is a kind of herb used in traditional Chinese medicine. Wild Hedyotis diffusa can be found in China, Japan, Nepal....
  
  
• Hedyotis flynnii
• Hedyotis littoralis
• Hedyotis mannii
• Hedyotis parvula
• Hedyotis purpurea
• Hedyotis schlechtendahliana
• Hedyotis st.-johnii
• Hedyotis terminalis
• Hedyotis vegrandis

Research

In the traditional medicine, over 20 Hedyotis species have been used for treatment of diseases and in healing practices. The most popular among these are Hedyotis diffusa and Hedyotis corymbosa which are active principles in several Chinese remedies such as bai hua she she cao, peh hue juwa chi cao and feibao syrup. They are taken for treatment of cancers, infections and other diseases. Phytochemical investigation of Hedyotis species was first published in 1933 upon examining the active components of the medicinal plant H. auricularia . Since then, over 50 novel compounds have been isolated from various member of the Hedyotis genus. These compounds have highly divergent structures including alkaloids, anthraquinones, flavonoids, iridoids, triterpenoids, sterols, lignans and a number of other compounds .

Recently, two novel biological active peptides, hedyotide B1 and B2 (hedyotide = hedyotis + peptide), have been isolated from the ariel parts of the medicinal plant Hedyotis biflora . H. biflora is a small annual herb traditionally used to treat body pain in fever and malaria. Both hedyotide B1 and B2 belong to the cyclotide superfamily which was known to be an important part of plant innate defense. Hedyotide B1 has a cyclic-cystine-knot motif and displayed potent broad-spectrum activites against many bacteria including E. coli, S. salivarius, S. aureus, P. aeruginosa, B. cereus and B. megaterium . Hedyotide B1 and cyclotides are likely to exerted their antimicrobial actions by disrupting the bacteria membranes which eventually leads to cell death. As they target directly bacterial membranes. it is unlikely for bacteria to develop resistance. Therefore, hedyotide B1 with a novel mode of action has potential as a novel antimicrobial agent against drug-resistance bacteria.

External links

• Hedyotis At: Search Page At: World Checklist of Rubiaceae At: Index by Team At: Projects At: Science Directory At: Scientific Research and Data At: Kew Gardens
• Hedyotis At:Index Nominum Genericorum At: References At: NMNH Department of Botany
• Hedyotis In: volume I Of: Species Plantarum At: Titles At: Biodiversity Heritage Library