Friday, 1 November 2019

October phytochemicals: what gives pumpkin spice its flavor?

A mouthful to say and something to avoid putting in your mouth: Oxalyldiaminopropionic acid - a neurotransmitter analog from the legume Lathyrus sativus - can cause lathyrism, a neurological disorder + lower body paralysis and (lookout!) gluteal emaciation! #PhytochemicalFriday

This #PhytochemicalFriday, be thankful for processing that removes alkaloids (like the pyrrolizidine ester amabiline) from apparently hangover-curing borage oil. Far from amable, amabiline is toxic to the liver and is one of several Boraginales alkaloids that can kill Amoebozoa.

Happy #PhytochemicalFriday! Furfural - though not strictly a plant chemical, it is a byproduct of agricultural plant processing (oats, corn, etc.). It's also part of the smell of old books, and its abundance can apparently be used to gauge the age and condition of some books.

If you taste pumpkin spice this fall, note that some of the flavors in many such lattes come from zingiberene - a compound that also contributes to the characteristic flavor of ginger rhizomes (Zingiber officinale). Happy #PhytochemicalFriday!

Wednesday, 9 October 2019

September phytochemicals - what gives Fresca its fresh flavor?

Part of the chemical basis for the earthy smell following rain: geosmin - a terpenoid compound produced by some bacteria but also by beets (Beta vulgaris) as part of their signature earthy flavor. Thanks @mishaploid for another awesome #PhytochemicalFriday suggestion!

Psoralen - a naturally-occurring compound in fig leaves, celery, & parsley (among others) - is a flat molecule capable of squeezing into the DNA double helix and impeding DNA replication. It appears to be responsible for fig leaf photodermatitis. #PhytochemicalFriday (the 13th)!

Nootkatone, a component in the signature aroma of grapefruit, has a variety of insecticidal properties, protecting the various plants that make it. It's non-toxic to humans though (GRAS), and is a key component of various products, including Fresca! #PhytochemicalFriday

Happy #PhytochemicalFriday from @UMDSwenson in Duluth, MN! Today: tremetone, a component of the toxic mixture tremetol from white snakeroot (Ageratina altissima). It can poison consumers of milk from cows that've eaten the plant - killed many in the 1800s (Abe Lincoln's mother!?)

Thursday, 12 September 2019

August phytochemicals - bioactive compounds from kava root!

Happy #PhytochemicalFriday.. uh - Saturday! Today: triptolide, a toxic terpenoid (defense compound?) from the thunder god vine Tripterygium wilfordii, whose structural analog minnelide is in Phase II clinical trials as a trtmnt for pancreatic cancer. Amazing 3x epoxide structure!

Happy #PhytochemicalFriday! Today: kavain, an ethnomedicine from the roots of the kava plant (Piper methysticum) that has anxiety-reducing effects. Incredible new work from @tomas_pluskal uncovers the biosynthesis of kavain (and many other molecules), featured in @NaturePlants.

#PhytochemicalFriday! This week, another compound from the thunder god vine (Tripterygium wilfordii) - celastrol - for which the first biosynthetic step has recently been discovered. It is being investigated for a variety of potential anti-cancer/obesity/inflammatory effects.

Happy #PhytochemicalFriday from #CASFutureLeaders @CASChemistry in Columbus, OH! Today: azadirachtin, a complex terpenoid from the neem tree (Azadirachta indica, meliaceae) that is toxic to insects (protects the tree), but is also used in a wide variety of commercial insecticides.

#PhytochemicalFriday! Today: dicoumarol - a compound of combined plant and fungal origin originally discovered in 1940 by studying spoiled sweet clover hay that caused uncontrollable and fatal hemorrhaging in livestock. It has since inspired synthetic anticoagulant rodenticides.

Monday, 5 August 2019

July phytochemicals - chemotheraputics from plants and more

Camptothecin - an alkaloid discovered during a natural products anticancer activity screen - is a topoisomerase inhibitor originally isolated from Camptotheca acuminata, a plant in traditional Chinese medicine. Structural analogs are current chemotheraputics!

This week: quassin, a (degraded) triterpenoid found in Quassia amara that is apparently one of the most bitter compounds in the world - as many as 50 times more bitter than quinine! It and its structural relatives exhibit a variety of biological activites.

Podophyllotoxin - a lignan derivative from above ground roots of mayapple. It can be converted into etoposide, a chemotheraputic on the WHO's list of essential medicines.

Today: (iso)masticadienonic acids - two compounds in mastic, a resin from the tree Pistacia lentiscus. These compounds may contribute to the resin's many reported bioactivites, for which it is featured on today's @nytimes front page.

Tuesday, 2 July 2019

June phytochemicals: the start of Project #ChemicalBlooms!

Did you know that capsaicin is not the only spicy molecule in peppers (Capsicum)? Several structural variants can also accumulate to substantial levels: dihydrocapsaicin is about as spicy as capsaicin itself; nordihydrocapsaicin, about half as spicy.

Aristolochic acid, a biosynthetic relative of morphine: found in the birthwort family Aristolochiaceae, it toxifies some butterflies that grow up on such plants. Birthworts are used in traditional medicine, but the acid is linked to kidney issues and cancer.

CALLING ALL BIOPROSPECTORS! Seen white coatings on plants? Each is unique, on Dudleya brittonii, it's mainly amyrins - bioactive & protective compounds. Help advance our understanding of these coatings: join Project #ChemicalBlooms: Please send pics of chemical blooms on twitter (@PlantsRChemists), instagram (@chemical_blooms), or email for a bioprospecting kit - sample the blooms yourself and send them in for analysis using the included stamped envelope. Best #FirstDayofSummer ever!

Reserpine, used in combo with other compounds to treat high blood pressure. Structurally, a combo of aromatic amino acid and terpenoid pathway products. Found in Rauvolfia serpentina (indian snakeroot; milkweed family) occurring in combo with other alkaloids.

Thursday, 20 June 2019

May phytochemicals - spring scents and conifer essential oils

Is it #SpringTime where you live? If lawn mowing has begun, think cis-3-Hexenal. A primary contributor to the smell of freshly cut grass, this small aldehyde is enzymatically derived from the tail end of linoleic acid. Thanks @chdiep for the #PhytochemicalFriday suggestion!

Recent discovery! A gene from Leucosceptrum canum (mint family) underlying the synthesis of the tricyclic sesquiterpene cedrol, an important aroma compound found in conifer essential oils and some mints = potential for a synthetic biology-based cedrol supply.

Kainic and domoic acids: compounds from some Ceramiales (red algae) that accumulate in shellfish & sardines. As neuronal stimulants, these acids can affect marine predators (inspiring scenes in Hitchcock's "The Birds"?) & are used in neurological research.

Hyperforin, a compound from the genus Hypericum (which includes the medicinal herb St. John's Wort) that scientists suspect is involved in the plant's various reported pharmacological effects. Seems derived from prenylation of phloroglucinol.

Pinoresinol, a lignan made of two monomers by oxidase enzymes. Cooccurring dirigent proteins (first discovered during study of Forsythia intermedia lignans) are not catalytically active themselves, but control a coupling reaction's stereochemical outcome.

Thursday, 16 May 2019

April Phytochemicals - complex and psychedelic structures

Taxol - found by a @USDA botanist screening plants for new cancer drugs - enhances microtubule stability, interfering with cell division. Originally isolated from the bark of Taxus brevifolia, then chemically synthesized, now grown in cell culture.

Another complex structure: moroidin - a bicyclic peptide with unusual leu-trp and trp-his links (in yellow). Found in Dendrocnide moroides (Urticaceae), it's a tubulin polymerization inhibitor that gives the plant's silica-tipped hairs a sting!

Two harmala alkaloids - harmine and harmaline - from (among others) Banisteriopsis caapi, aka ayahuasca (Malpighiales). These fluorescent beta-carbolines are monoamine oxidase inhibitors - an activity that promotes the psychoactive effects of DMT.

Thinking about garden layout? Don't forget companion Chrysanthemums. Several species produce pyrethrins - a group of biodegradable, insecticidal (terpenoid!) compounds. These alternatives to synthetic pyrethroids (permethrin) can reduce aquatic poisonings.