There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

http://naturalingredient.org/wp/wp-content/uploads/Burt_Essential_Oils_A_Review_2004.pdf

Essential oils: their antibacterial properties and potential applications in foods--a review.

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Natural products: a continuing source of novel drug leads.

As the largest class of natural products, terpenes have a variety of roles in mediating antagonistic and beneficial interactions among organisms. They defend many species of plants, animals and microorganisms against predators, pathogens and competitors, and they are involved in conveying messages to conspecifics and mutualists regarding the presence of food, mates and enemies. Despite the diversity of terpenes known, it is striking how phylogenetically distant organisms have come to use similar structures for common purposes. New natural roles undoubtedly remain to be discovered for this large class of compounds, given that such a small percentage of terpenes has been investigated so far.

The function of terpene natural products in the natural world.

The factors affecting oil yield and quality of essential oils from Dalmatian sage (Salvia officinalis L.) are analyzed. Distillations of oils from individual plants and GC analyses revealed the presence of three chemotypes with different proportions of α- and β-thujone (α/β 10:1, 1.5:1, and 1:10). Different accessions could also be classified as having high (39−44%), medium (22−28%), or low (9%) total thujone contents. Flowering parts of S. officinalis had higher oil contents (1.6 versus 1.1%) and β-pinene levels (27 versus 10%) than leaves and lower thujone levels (16 versus 31%). Major seasonal changes were found in the composition of oil distilled from a flowering type of Dalmatian sage, but oil yields from healthy, established plants did not vary greatly. Total thujone levels were lowest (25%) around flowering in spring and summer, so autumn or winter was the best harvest time to obtain oils with high thujone levels. Keywords: Dalmatian sage; Salvia officinalis; essential oil; variation; thujones

Nigel B. Perry

Papers

Essential oils from dalmatian sage (Salvia officinalis l.): variations among individuals, plant parts, seasons, and sites.

Extraction of phenolics and essential oil from dried sage (Salvia officinalis) using ethanol–water mixtures

Mycalamide A, an antiviral compound from a New Zealand sponge of the genus Mycale

Discorhabdin C, a highly cytotoxic pigment from a sponge of the genus Latrunculia

Cytotoxic pigments from new zealand sponges of the genus latrunculia : discorhabdins a, b and c