STAT-3 inhibitory bisabolanes from Carthamus glaucus

Natural Peroxides from Plants: Historical Discovery, Biosynthesis, and Biological Activities

Naturally occurring peroxides received great interest and attention from scientific research groups worldwide due to their structural diversity, versatile biological activities, and pharmaceutical properties. In the present review, we describe the historical discovery of natural peroxides from plants systematically and update the researchers with recently explored ones justifying their structural caterogrization and biological/pharmaceutical properties intensively. Till the end of 2023, 192 peroxy natural products from plants were documented herein for the first time implying most categories of natural scaffolds (e. g. terpenes, polyketides, phenolics and alkaloids). Numerically, the reported plants' peroxides have been classified into seventy-four hydro-peroxides, hundred seven endo-peroxides and eleven acyl-peroxides. Endo-peroxides (cyclic alkyl peroxides) are an important group due to their high variety of structural frameworks, and we have further divided them into "four-, five-, six and seven"-membered rings. Biosynthetically, a shedding light on the intricate mechanisms behind the formation of plant-derived peroxides are addressed as well.

Comparative Analysis of Volatile Compounds and Biochemical Activity of Curcuma xanthorrhiza Roxb. Essential Oil Extracted from Distinct Shaded Plants

The application of shade during plants' growth significantly alters the biochemical compounds of the essential oil (EO). We aimed to analyze the effect of shade on the volatile compounds and biochemical activities of EO extracted from Curcuma xanthorrhiza Roxb. (C. xanthorrhiza) plants. Four shading conditions were applied: no shading (S0), 25% (S25), 50% (S50), and 75% shade (S75). The volatile compounds of EO extracted from each shaded plant were analyzed by gas chromatography-mass spectrometry. The antioxidant, antibacterial, and antiproliferative activities of EO were also investigated. We found that shade application significantly reduced the C. xanthorrhiza EO yield but increased its aroma and bioactive compound concentration. α-curcumene, xanthorrhizol, α-cedrene, epicurzerenone, and germacrone were found in EO extracted from all conditions. However, β-bisabolol, curzerene, curcuphenol, and γ-himachalene were only detected in the EO of S75 plants. The EO of the shaded plants also showed higher antioxidant activity as compared to unshaded ones. In addition, the EO extracted from S75 exerted higher antiproliferative activity on HeLa cells as compared to S0. The EO extracted from S0 and S25 showed higher antibacterial activity against Gram-positive bacteria than kanamycin. Our results suggest that shade applications alter the composition of the extractable volatile compounds in C. xanthorrhiza, which may result in beneficial changes in the biochemical activity of the EO.

Sesquiterpenoids from the Florets of Carthamus tinctorius (Safflower) and Their Anti-Atherosclerotic Activity

(1) Background: The florets of Carthamus tinctorius L. are traditionally used as a blood-activating drug and can be used for the treatment of atherosclerosis, but no compounds with anti-atherosclerotic activity have been reported. (2) Methods: This study investigated the chemical compounds from the florets of C. tinctorius. Comprehensive spectroscopic techniques revealed their structures, and ECD calculations established their absolute configurations. Nile Red staining, Oil Red O staining, and cholesterol assessment were performed on these compounds and their aglycones for the inhibitory activity against the formation of foam cells induced by oxidized low-density lipoprotein (ox-LDL) in RAW264.7 macrophages. In addition, RAW264.7 macrophages were tested for their anti-inflammatory activity by measuring the inhibition of NO production caused by LPS. (3) Results: Five new sesquiterpenoids (1-5) isolated from the florets of C. tinctorius were identified as (-)-(1R,4S,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (1), (+)-(1R,4R,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (2), (-)-(3Z,1R,5S,8S,9S,11R)-5,8-epoxycaryophyll-3-en-14-O-β-D-glucopyranoside (3), (+)-(1S,7R,10S)-guai-4-en-3-one-11-O-β-D-fucopyranoside (4), and (-)-(2R,5R,10R)-vetispir-6-en-8-one-11-O-β-D-fucopyranoside (5). All compounds except for compound 3 reduced the lipid content in ox-LDL-treated RAW264.7 cells. Compounds 3 and 4 and their aglycones were found to reduce the level of total cholesterol (TC) and free cholesterol (FC) in ox-LDL-treated RAW264.7 cells. However, no compounds showed anti-inflammatory activity. (4) Conclusion: Sesquiterpenoids from C. tinctorius help to decrease the content of lipids, TC and FC in RAW264.7 cells, but they cannot inhibit NO production, which implies that their anti-atherogenic effects do not involve the inhibition of inflammation.

Pharmacological and biological effects of alpha-bisabolol: An updated review of the molecular mechanisms

Alpha-bisabolol (α-bisabolol), an unsaturated monocyclic sesquiterpene alcohol, is known as one of the "most-used herbal constituents" in the world. Various therapeutic and biological properties of α-bisabolol in preventing oxidative stress, inflammatory disorders, infections, neurodegenerative diseases, cancers, and metabolic disorders have been reported. In this review, we evaluated new findings regarding the molecular mechanisms of α-bisabolol published from 2010 until 2021 in PubMed, Science Direct, and Scopus. The antioxidant mechanism of α-bisabolol is mainly associated with the reduction of ROS/RNS, MDA, and GSH depletion, MPO activity, and augmentation of SOD and CAT. Additionally, upregulating the expression of bcl-2 and suppression of bax, P53, APAF-1, caspase-3, and caspase-9 activity indicates the anti-apoptotic effects of α- bisabolol. It possesses anti-inflammatory effects via reduction of TNF-α, IL-1β, IL-6, iNOS, and COX-2 and suppresses the activation of ERK1/2, JNK, NF-κB, and p38. The antimicrobial effect is mediated by inhibiting the viability of infected cells and improves cognitive function via downregulation of bax, cleaved caspases-3 and 9 levels, β-secretase, cholinesterase activities, and upregulation of bcl-2 levels. Finally, due to multiple biological activities, α-bisabolol is worthy to be subjected to clinical trials to achieve new insights into its beneficial effects on human health.

Bisabolane-type sesquiterpenoids: Structural diversity and biological activity

Bisabolane-type sesquiterpenoids, a class of monocyclic sesquiterpenoids, are widely distributed in nature and have a variety of biological activities. To provide a reference for the further research and development of these compounds, the phytochemical and biological properties of natural bisabolane-type sesquiterpenoids (356 compounds in total) isolated between 1985 and 2020 from 24 families, primarily Compositae, Zingiberaceae, Aspergillaceae, Halichondriidae, and Aplysiidae were reviewed. In vitro and in vivo studies have indicated that antibacterial, anti-inflammatory, and cytotoxic effects are the most commonly reported pharmacological properties of bisabolane-type sesquiterpenoids. Owing to their extensive significant effects, a lot of traditional medicines containing this type of compounds have been used for a long history. Thus, bisabolane-type sesquiterpenoids are a rich source of important natural products, which show great potential for the development of new drugs.

Boronic Acid-Catalyzed Final-Stage Site-Selective Acylation for the Total Syntheses of O-3'-Acyl Bisabolol β-D-Fucopyranoside Natural Products and Their Analogues

The first concise total syntheses of O-3'-senecioyl α-bisabolol β-D-fucopyranoside (4a) and O-3'-isovaleroyl α-bisabolol β-D-fucopyranoside (4b) were achieved through final-stage site-selective acylation via the activation of cis-vicinal diols by imidazole-containing boronic acid catalysts as a key step. This synthetic method was also effective for the syntheses of unnatural analogues with modified acyl side chains or carbohydrate moiety.

Palladium catalyzed oxidation of renewable terpenes with molecular oxygen: oxidation of α-bisabolol under chloride-free nonacidic conditions

A novel selective palladium catalyzed oxidation of α-bisabolol by molecular oxygen under chloride-free nonacidic conditions has been developed.

Palladium catalyzed oxidation of renewable terpenes with molecular oxygen: oxidation of α-bisabolol under chloride-free conditions

Several novel compounds potentially useful as components of synthetic perfumes and cosmetics were obtained from α-bisabololviapalladium-catalyzed aerobic oxidation.

Natural products and their derivatives regulating the janus kinase/signal transducer and activator of transcription pathway

Janus kinase/signal transducer and activator of transcriptions (JAK/STAT) signaling pathway is one of the major signaling pathways involved in a variety of human physiological and pathological process. The proteins of JAK/STAT pathway or interferon response element (such as JAK, STAT, Src, SOCS, 2'5'-OAS, and ISRE) might be as drug targets for the study of physiological processes and treatment of related diseases, including cell proliferation, differentiation, apoptosis and immune processes, inflammation, cancer, arthritis, asthma, diabetes, and other diseases. This review attempts to summarize the current status of natural products and their derivatives (2002-2013) regulating the proteins or transcription elements of JAK/STAT signaling pathway to supply a new direction or drug targets for the discovery of new drugs.

Acetylated dammarane-type bisdesmosides from Combretum inflatum

The first study of the chemical constituents of Combretum inflatum has resulted in the isolation of seven new acetylated dammarane-type bisdesmosides (1-7). Their structures were determined from microgram quantities on hand using Bruker BioSpin TCI 1.7 mm MicroCryoProbe technology, ESIMS, and comparison to data found in the literature. Compounds 1-7 were screened for inhibition of an Escherichia coli strain UTI89 biofilm, MRSA inhibition, and cytotoxicity in NCI-H460 human lung cancer cells. Compounds 3-7 reduced the growth of MRSA at 16 μg/mL by 71-45%, and compound 7 had an IC₅₀ value of 3.9 μM in NCI-H460.

Peroxy natural products

This review covers the structures and biological activities of peroxy natural products from a wide variety of terrestrial fungi, higher plants, and marine organisms. Syntheses that confirm or revise structures or stereochemistries have also been included, and 406 references are cited.

Natural sesquiterpenoids

This review covers the isolation, structural determination, synthesis and chemical and microbiological transformations of natural sesquiterpenoids. The literature from January to December 2012 is reviewed, and 471 references are cited.