I read this book the same weekend that the Packers took on the Rams, and the experience of the latter event, obviously, colored my judgment. Although I abhor anything that smacks of being a handbook (like, \"How to Earn a Merit Badge in Neurosurgery\") because too many volumes in biomedical science already evince a boyscout-like approach, I must confess that parts of this volume are fast, scholarly, and significant, with certain reservations. I like parts of this well-illustrated book because Dr. Sj6strand, without so stating, develops certain subjects on technique in relation to the acquisition of judgment and sophistication. And this is important! So, given that the author (like all of us) is somewhat deficient in some areas, and biased in others, the book is still valuable if the uninitiated reader swallows it in a general fashion, realizing full well that what will be required from the reader is a modulation to fit his vision, propreception, adaptation and response, and the kind of problem he is undertaking. A major deficiency of this book is revealed by comparison of its use of physics and of chemistry to provide understanding and background for the application of high resolution electron microscopy to problems in biology. Since the volume is keyed to high resolution electron microscopy, which is a sophisticated form of structural analysis, but really morphology in a modern guise, the physical and mechanical background of The instrument and its ancillary tools are simply and well presented. The potential use of chemical or cytochemical information as it relates to biological fine structure , however, is quite deficient. I wonder when even sophisticated morphol-ogists will consider fixation a reaction and not a technique; only then will the fundamentals become self-evident and predictable and this sine qua flon will become less mystical. Staining reactions (the most inadequate chapter) ought to be something more than a technique to selectively enhance contrast of morphological elements; it ought to give the structural addresses of some of the chemical residents of cell components. Is it pertinent that auto-radiography gets singled out for more complete coverage than other significant aspects of cytochemistry by a high resolution microscopist, when it has a built-in minimal error of 1,000 A in standard practice? I don't mean to blind-side (in strict football terminology) Dr. Sj6strand's efforts for what is \"routinely used in our laboratory\"; what is done is usually well done. It's just that …

Methods in Enzymology.

Pyrrolizidine alkaloids: occurrence, biology, and chemical synthesis

https://pubs.rsc.org/en/content/articlepdf/2016/np/c6np00059b

Diterpenoids of terrestrial origin

The saponins are a diverse class of natural products, with a broad scale distribution across different plant species. Chemically characterized as triterpenoid glycosides, they posses a 30C oxidosqualene precursor-based aglycone moiety (sapogenin), to which glycosyl residues are subsequently attached to yield the corresponding saponin. Based on the chemically distinct aglycone moieties, broadly, they are divided into triterpenoid saponins (dammaranes, ursanes, oleananes, lupanes, hopanes, etc.) and the sterol glycosides. This review aims to present in detail the biosynthesis patterns of the different aglycones from a common precursor and their glycosylation patterns to yield the functionally active glycoside. The review also presents recent advances in the pharmacological activities of these saponins, particularly as potent anti-neoplastic pharmacophores, antioxidants, or anti-viral/antibacterial agents. Since alternate production pedestals for these pharmacologically important triterpenes via cell and tissue cultures are an attractive option for their sustainable production, recent trends in the variety and scale of in vitro production of plant triterpenoids have also been discussed.

Plant triterpenoid saponins: biosynthesis, in vitro production, and pharmacological relevance

A potential use of vine-shoot wastes: The antioxidant, antifeedant and phytotoxic activities of their aqueous extracts

Bioactive constituents from transformed root cultures of Nepeta teydea

Bioactive compounds from transformed root cultures and aerial parts of Bethencourtia hermosae

Biotransformation of an africanane sesquiterpene by the fungus Mucor plumbeus

Teydealdehyde, a C23-terpenoid from transformed root cultures of Nepeta teydea

Teydealdehyde, a C 23 -terpenoid with a new carbon skeleton, has been isolated from Nepeta teydea root cultures transformed by Agrobacterium rhizogenes . Its structure, determined from HRMS, 1 D and 2 D NMR data, shows four cycles with a five membered A ring deoxygenated at C-3 and with a C-2 aldehyde group at C-1. The B-, C- and D-rings are similar to those of the oleanane, ursane and lupane triterpenes, but the last cycle contains an α,β-unsaturated ketone as the result of a ring E biodegradation process of a pentacyclic triterpene precursor.

Leonardo J. Amador

Papers

Bioactive constituents from transformed root cultures of Nepeta teydea

Bioactive compounds from transformed root cultures and aerial parts of Bethencourtia hermosae

Biotransformation of an africanane sesquiterpene by the fungus Mucor plumbeus

Teydealdehyde, a C23-terpenoid from transformed root cultures of Nepeta teydea

Teydealdehyde, a C23‐Terpenoid from Transformed Root Cultures of Nepeta teydea.