Exploits

The paper identifies the cytochrome P450 sterol side chain cleaving enzyme (P450 scc) in the foxglove plant, which catalyzes the first and rate-limiting step in digoxin biosynthesis. This enzyme converts cholesterol and campesterol to pregnenolone, suggesting that digoxin biosynthesis starts from both sterols, unlike previously reported.

Cardenolides are steroidal metabolites in Digitalis lanata with potent cardioactive effects on animals. In plants, cardenolides are likely involved in various stress responses. However, the molecular mechanism of cardenolide increase during stresses is mostly unknown. Additionally, cardenolides are proposed to arise from cholesterol, but indirect results show that phytosterols may also be substrates for cardenolide biosynthesis. Here, we show that cardenolides increased after methyl jasmonate (MJ), sorbitol, potassium chloride (KCl) and salicylic acid analog [2,1,3-benzothiadiazole (BTH)] treatments. However, the expression of three known genes for cardenolide biosynthesis did not correlate well with these increases. Specifically, the expression of progesterone-5β-reductases (P5βR and P5βR2) did not correlate with the cardenolide increase. The expression of 3β-hydroxysteroid dehydrogenase (3βHSD) correlated with changes in cardenolide levels only during the BTH treatment. Mining the D. lanata transcriptome identified genes involved in cholesterol and phytosterol biosynthesis: C24 sterol sidechain reductase 1 (SSR1), C4 sterol methyl oxidase 1, and 3 (SMO1 and SMO3). Surprisingly, the expression of all three genes correlated well with the cardenolide increase after the BTH treatment.

The work focuses on the analysis of cardenolides, which are compounds found in plants of the Digitalis genus and are commonly used to treat heart failure. The conventional method of quantifying cardenolides in Digitalis extracts is insufficient due to the lack of structural information and possible co-elution of compounds. The paper aims to structurally characterize cardiac glycosides in fresh-leaf extracts using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) that provides measured accurate mass. The paper also discusses the fragmentation of cardenolides and the sequence of elution for different types of cardenolides. The paper serves as a foundation for complete identification and accurate quantification of cardiac glycosides, which is necessary for understanding the biosynthesis of cardenolide in plants.

The paper presents a new method for analyzing cardenolides in plant extracts using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) that provides measured accurate mass. The paper also discusses the structural characterization of cardiac glycosides in fresh-leaf extracts and the identification of seventeen cardenolides in Digitalis lanata and seven in Digitalis purpurea.

Alpinia galanga (L.) Willd. is a valuable medicinal crop found in specific tropical regions of southeast Asia. Its crude extracts are well known for their wide medicinal properties and many compounds identified from these extracts are of great interest currently. 1’S-1’-Acetoxychavicol acetate (ACA) obtained from rhizomes of A.galanga is one such well-illustrated compound. This study strives to progress and simplifies the purification protocol for ACA from A.galanga rhizomes. It also studies the cytotoxicity and antiproliferative activity of ACA against Dukes’ type B, colorectal adenocarcinoma (SW480).

Little information is available on seed dormancy of members of the Zingiberales and especially the Zingiberaceae. Our aim was to investigate the dormancy breaking and germination requirements of Alpinia galanga in vitro with a minimum number of seeds, using the move-along experiment. The ideal temperature for embryo growth was 20°C. Since GA3 and dry storage can break non-deep physiological dormancy and embryos grew during warm stratification, seeds of A. galanga have non-deep simple morphophysiological dormancy (MPD). This is the first report of non-deep simple MPD in the Zingiberaceae.

Objective: Elimination of endophytic actinomycetes before micropropagation using antibiotic pre-treatment in rhizome bud explants of Alpinia
galanga. Formulation of an operative protocol for micropropagation from the disinfected rhizome bud explants in Alpinia galanga.
Conclusion: This study shows the potency of Rifampicin and Fusidic acid to disinfect explants from actinomycete endophytes and is significant
as the first report on curbing actinomycetes endophytes in plant tissue culture of A. galanga. This is also the first report conferring the dissimilar
regeneration capabilities of TDZ in comparison to other cytokinins in Zingiberaceae.