Three Terpenoids and a Tocopherol-Related Compound from Ricinus communis

Bioactive-Based Cosmeceuticals: An Update on Emerging Trends

Cosmetic-containing herbals are a cosmetic that has or is claimed to have medicinal properties, with bioactive ingredients purported to have medical benefits. There are no legal requirements to prove that these products live up to their claims. The name is a combination of “cosmetics” and “pharmaceuticals”. “Nutricosmetics” are related dietary supplements or food or beverage products with additives that are marketed as having medical benefits that affect appearance. Cosmetic-containing herbals are topical cosmetic–pharmaceutical hybrids intended to enhance the health and beauty of the skin. Cosmetic-containing herbals improve appearance by delivering essential nutrients to the skin. Several herbal products, such as cosmetic-containing herbals, are available. The present review highlights the use of natural products in cosmetic-containing herbals, as natural products have many curative effects as well as healing effects on skin and hair growth with minimal to no side effects. A brief description is given on such plants, their used parts, active ingredients, and the therapeutic properties associated with them. Mainly, the utilization of phytoconstituents as cosmetic-containing herbals in the care of skin and hair, such as dryness of skin, acne, eczema, inflammation of the skin, aging, hair growth, and dandruff, along with natural ingredients, such as for hair colorant, are explained in detail in the present review.

Chemical constituents from the leaves of Elaeocarpus floribundus

The genus Elaeocarpus belongs to the Elaeocarpaceae family, consists of about 350 species distributed in the tropical and subtropical regions. Plants in the genus, reportedly, contain compounds known for various biological activities like affinity for the δ-opioid receptor, antioxidant, cytotoxicity and antimicrobial activities. Elaeocarpus floribundus, commonly known in India as 'Indian Olive' is a medicinal plant widely distributed through Eastern Asia and the pacific. Here, we report the isolation and spectroscopic characterization of fifteen compounds (1-15) and additional three compounds (16-18) were obtained as mixtures. This includes four fatty acids, three diterpenoids, one triterpene alcohol, two fatty alcohols, three phaeophytins, one phytosterol, one sesquiterpene, and three hydrocarbons from the hexane extract of the leaves. Compounds 1-18 are reported for the first time from this source. To the best of our knowledge, this is an initial report of the isolation of compounds 1-11, and 14-18 from the genus Elaeocarpus.

Synthesis of Gold Nanoparticles (AuNPs) Using Ricinus communis Leaf Ethanol Extract, Their Characterization, and Biological Applications

The purpose of this study was to explore the collective biological properties of Ricinus communis ethanol leaf extract (RcExt) and extract-fabricated gold nanoparticles (RcExt-AuNPs). AuNPs were synthesized using RcExt. Fingerprint data of the biochemicals putatively found in RcExt were obtained using gas chromatography-mass spectrometry (GC-MS/MS) and high-performance liquid chromatography/ultraviolet-visible (HPLC/UV-VIS) analyses. RcExt-AuNPs were characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), and Fourier- transform infrared radiation (FTIR) spectroscopy. Cytotoxic activity on the Hela and HepG2 tumor cell lines was tested through cell viability, antimicrobial activity against bacterial and fungal pathogens through a well diffusion assay, hemolytic activity on red blood cells through absorbance reading, and stimulatory/inhibitory effects on splenic cells by cell viability. AuNPs of 200 nm size were synthesized. GC-MS/MS analysis revealed 12 peaks and HPLC/UV-VIS analysis resulted in 18, 13, and five peaks at the wavelengths of 220, 254, and 300 nm, respectively. Cytotoxicity screening revealed that RcExt had stimulatory effects (6.08%) on Hela cells and an inhibitory effect (-28.33%) on HepG2 cells, whereas RcExt-AuNPs showed inhibitory effects (-58.64% and -42.74%) on Hela and HepG2 cells, respectively. Antimicrobial activity of RcExt-AuNPs against tested pathogens was significantly higher (average diameters of inhibition zones were higher (ranging from 9.33 mm to 16.33 mm)) than those of RcExt (ranging from 6.00 mm to 7.33 mm). RcExt and RcExt-AuNPs showed 4.15% and 100% lytic effects, respectively. Inhibitory effects on splenic cells for RcExt-AuNPs were observed to be significantly higher (-30.56% to -72.62%) than those of RcExt (-41.55% to -62.25%) between concentrations of 25 to 200 µg/mL. RcExt-AuNPs were inhibitory against HepG2 and Hela cells, while RcExt inhibited HepG2 but stimulated Hela cells. RcExt-AuNPs showed comparatively more antimicrobial activity. RcExt was safe while RcExt-AuNPs harmful to red blood cells (RBCs). RcExt and RcExt-AuNPs showed inhibitory effects on splenic cells irrespective of dose.

Oxidation and cyclization of casbene in the biosynthesis of Euphorbia factors from mature seeds of Euphorbia lathyris L

The seed oil of Euphorbia lathyris L. contains a series of macrocyclic diterpenoids known as Euphorbia factors. They are the current industrial source of ingenol mebutate, which is approved for the treatment of actinic keratosis, a precancerous skin condition. Here, we report an alcohol dehydrogenase-mediated cyclization step in the biosynthetic pathway of Euphorbia factors, illustrating the origin of the intramolecular carbon-carbon bonds present in lathyrane and ingenane diterpenoids. This unconventional cyclization describes the ring closure of the macrocyclic diterpene casbene. Through transcriptomic analysis of E. lathyris L. mature seeds and in planta functional characterization, we identified three enzymes involved in the cyclization route from casbene to jolkinol C, a lathyrane diterpene. These enzymes include two cytochromes P450 from the CYP71 clan and an alcohol dehydrogenase (ADH). CYP71D445 and CYP726A27 catalyze regio-specific 9-oxidation and 5-oxidation of casbene, respectively. When coupled with these P450-catalyzed monooxygenations, E. lathyris ADH1 catalyzes dehydrogenation of the hydroxyl groups, leading to the subsequent rearrangement and cyclization. The discovery of this nonconventional cyclization may provide the key link to complete elucidation of the biosynthetic pathways of ingenol mebutate and other bioactive macrocyclic diterpenoids.

Investigation of terpene diversification across multiple sequenced plant genomes

Plants produce an array of specialized metabolites, including chemicals that are important as medicines, flavors, fragrances, pigments and insecticides. The vast majority of this metabolic diversity is untapped. Here we take a systematic approach toward dissecting genetic components of plant specialized metabolism. Focusing on the terpenes, the largest class of plant natural products, we investigate the basis of terpene diversity through analysis of multiple sequenced plant genomes. The primary drivers of terpene diversification are terpenoid synthase (TS) "signature" enzymes (which generate scaffold diversity), and cytochromes P450 (CYPs), which modify and further diversify these scaffolds, so paving the way for further downstream modifications. Our systematic search of sequenced plant genomes for all TS and CYP genes reveals that distinct TS/CYP gene pairs are found together far more commonly than would be expected by chance, and that certain TS/CYP pairings predominate, providing signals for key events that are likely to have shaped terpene diversity. We recover TS/CYP gene pairs for previously characterized terpene metabolic gene clusters and demonstrate new functional pairing of TSs and CYPs within previously uncharacterized clusters. Unexpectedly, we find evidence for different mechanisms of pathway assembly in eudicots and monocots; in the former, microsyntenic blocks of TS/CYP gene pairs duplicate and provide templates for the evolution of new pathways, whereas in the latter, new pathways arise by mixing and matching of individual TS and CYP genes through dynamic genome rearrangements. This is, to our knowledge, the first documented observation of the unique pattern of TS and CYP assembly in eudicots and monocots.

Production of bioactive diterpenoids in the euphorbiaceae depends on evolutionarily conserved gene clusters

The Euphorbiaceae produce a diverse range of diterpenoids, many of which have pharmacological activities. These diterpenoids include ingenol mebutate, which is licensed for the treatment of a precancerous skin condition (actinic keratosis), and phorbol derivatives such as resiniferatoxin and prostratin, which are undergoing investigation for the treatment of severe pain and HIV, respectively. Despite the interest in these diterpenoids, their biosynthesis is poorly understood at present, with the only characterized step being the conversion of geranylgeranyl pyrophosphate into casbene. Here, we report a physical cluster of diterpenoid biosynthetic genes from castor (Ricinus communis), including casbene synthases and cytochrome P450s from the CYP726A subfamily. CYP726A14, CYP726A17, and CYP726A18 were able to catalyze 5-oxidation of casbene, a conserved oxidation step in the biosynthesis of this family of medicinally important diterpenoids. CYP726A16 catalyzed 7,8-epoxidation of 5-keto-casbene and CYP726A15 catalyzed 5-oxidation of neocembrene. Evidence of similar gene clustering was also found in two other Euphorbiaceae, including Euphorbia peplus, the source organism of ingenol mebutate. These results demonstrate conservation of gene clusters at the higher taxonomic level of the plant family and that this phenomenon could prove useful in further elucidating diterpenoid biosynthetic pathways.

Male contraceptive efficacy of Ricinus communis L. extract

ETHNOPHARMACOLOGICAL RELEVANCE

Ricinus communis L. (Rc), of Euphorbiaceae family is a widespread plant in tropical regions and it is used in traditional medicines as an antifertility agent in India and different parts of the world.

AIM OF THE STUDY

The aim of the present study is to revalidate the ethnobotanical knowledge by evaluating the activity of only crude stem bark extracts of Rc. In this study, effects of extracts on male contraceptive efficacy were experimented in vitro with human sperm sample. The work is based on primordial and contemporary therapeutic uses of this plant.

MATERIALS AND METHODS

In this study, dose of petroleum ether extract, ethyl acetate extract, acetone extract and lyophilised aqueous extract of Rc were added to fresh human semen in 1:1 volumetric ratio. As the aqueous extract showed a promising result in 1:1 ratio, therefore, the Hypo-osmotic swelling test (HOS), Nuclear chromatin decondensation test (NCD) and Acrosomal status and function test (AFT) were also carried out with the aqueous extract of Rc.

RESULTS

The sperm immobilisation effects of the extract appeared immediately in a dose-dependent manner when the samples were treated with four different extracts of this plant. At a concentration of 100mg/mL, 100% (p<0.001 and p<0.05) sperms lost their progressive motility. At a concentration of 300 mg/mL, 100% (p<0.001 and p<0.05) became immotile when treated with aqueous extract. There was 88% (p<0.001 and p<0.05) morphological deformities in sperm sample due the effect of aqueous extract when they were tested for HOS and 91% (p<0.05) sperms behaved against NCD as compared to control group. Also there was a distinct decline (p<0.05) in AFT with increase in dosage concentration.

CONCLUSION

The findings of the study revealed that aqueous stem bark extract of the plant showed dose dependent loss of sperm motility by influencing the morphological deformation, blockage in nuclear envelope and distinct declination in acrosomal status of spermatozoa. This research, thus, opens up scope for future exploration of bark of the plant as commercial source of new male contraceptive.

Chemical constituents from the aerial parts of Euphorbia sikkimensis and their bioactivities

Phytochemical investigation of the aerial parts of Euphorbia sikkimensis led to the isolation of one new diterpenoids, named sikkimenoid E (1), together with thirteen other known compounds (2–14). Their structures were established by means of spectroscopic methods. Compound 2 was identified to be a trinortriterpenoid, and derived for the first time from a natural source. In this paper we reveal for the first time its comprehensive spectral data and NMR spectral assignment. Compound 4 showed antiangiogenic activity with an IC₅₀ value of 5.66 µM in a zebrafish model, and compounds 5 and 6 exhibited cytotoxicity toward A549 cell line with IC₅₀ values of 12.12 and 6.45 µM, respectively.

Functional characterization of four sesquiterpene synthases from Ricinus communis (castor bean)

Genome sequence analysis of Ricinus communis has indicated the presence of at least 22 putative terpene synthase (TPS) genes, 13 of which appear to encode sesquiterpene synthases (SeTPSs); however, no SeTPS genes have been isolated from this plant to date. cDNAs were recovered for six SeTPS candidates, and these were subjected to characterization in vivo and in vitro. The RcSeTPS candidates were expressed in either Escherichia coli or Saccharomyces cerevisiae strains with engineered sesquiterpene biosynthetic pathways, but only two (RcSeTPS1 and RcSeTPS7) produced detectable levels of product. In order to check whether the engineered microbial hosts were adequately engineered for sesquiterpene production, a selection of SeTPS genes was chosen from other plant species and demonstrated consistently high sesquiterpene titers. Activity could be demonstrated in vitro for two of the RcSeTPS candidates (RcSeTPS5 and RcSeTPS10) that were not observed to be functional in our microbial hosts. RcSeTPS1 produced two products, (-)-α-copaene and (+)-δ-cadinene, while RcSeTPS7 produced a single product, (E, E)-α-farnesene. Both RcSeTPS5 and RcSeTPS10 produced multiple sesquiterpenes.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids, including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes and saponins; 278 references are cited.