Characterization of cultivars within species of Ocimum by exudate flavonoid profiles

Qualitative Profiling, Antioxidant and Antimicrobial Activities of Polar and Nonpolar Basil Extracts

Basil (Ocimum basilicum L.) is a widely used culinary herb. In this study, ethanol, dichloromethane, and sunflower oil were used separately as solvents with distinct polarities for the extraction of basil aerial parts to simulate the different polarity conditions in domestic food processing. The oil extract (OE) was re-extracted with acetonitrile, and the chemical composition, antioxidant potential, and antimicrobial activities of the ethanol (EE), dichloromethane (DCME), and acetonitrile (ACNE) extracts were determined. A total of 109 compounds were tentatively identified in EE, DCME, and ACNE by HPLC-DAD/ESI-ToF-MS. Fatty acids were present in all extracts. Phenolic acids and flavonoids dominated in EE. DCME was characterised by triterpenoid acids, while diterpenoids were mainly found in ACNE. The extracts were analysed for their antioxidant capacity using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. EE and DCME showed significant radical scavenging potential. Antimicrobial activity was explored in eight bacterial, two yeast, and one fungal species. All extracts exhibited high antifungal activity, comparable to or better than that of the commercial drug nistatin. Antibacterial activities were notable for EE and ACNE, while DCME showed no activity against bacteria in the applied concentration ranges. The different polarities of the solvents led to distinctive phytochemical compositions and bioactivities in the extracts.

Recent Advances in Standardization of Herbal Drugs

Background:

Herbal drugs play a significant role to maintain the human healthiness and to treat the ailments since the dawn of civilization. Moreover, these plants have provided many lead compounds that culminated in modern medicine. A single herb is regarded as mini-combinatorial library of phytoconstituents hence the quality control of herbal drugs in an herbal formulation is not an easy task because a number of factors impact their pharmacological efficiency and consistent therapeutic effects. Hence, to provide consistent beneficial therapeutic effects, standardized herbal products of consistent quality and purity are required.

Methods:

This review is based on publications obtained by a selective search in PubMed using the keywords “Standardized herbal products”, “fingerprinting”, “authentication”, “chemometric, hyphenated techniques”, “quality control of herbal drugs”, “identification”.

Results:

In the era of modernization, chromatographic techniques coupled with sophisticated spectroscopic analytical methods are used in estimating the authenticity, identity and characteristic of herbal products. Further, with the advancement of computer technology, chemometrics methods have become a leading tool with an unsupervised pattern recognition technique for handling multivariate data without prior knowledge about the studied samples and mines more beneficial and valuable information about the chemical entities from the raw data.

Conclusion:

Standardization of HDs chromatographic fingerprint is not always a perfect way to present all compounds. To assess the quality of medicinal plants, new ways are regularly being explored such as combination chemical fingerprint with biological methods, biofingerprint and metabolic fingerprint quality metrology, pharmacodynamics and export system of medicinal plants have been researched in some groups but still a significant amount of work is required to achieve a perfect system for quality evaluation of herbal drugs. Further, novel chemometric techniques have been unfolded that mines more beneficial and valuable information about the chemical entities from the raw data. So this review emphasis mainly on hyphenated techniques associated with chemometric method used in herbal drugs for identifying more valuable information and various methods for providing data, among which most commonly used techniques are chemometric resolution method and Principal Component Analysis (PCA) method.

Review: DNA Barcoding and Chromatography Fingerprints for the Authentication of Botanicals in Herbal Medicinal Products

In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.

Effect of Genotype and Environment on Salvia miltiorrhiza Roots Using LC/MS-Based Metabolomics

Salvia miltiorrhiza (S. miltiorrhiza) Bunge is broadly used as herbal medicine for the clinical treatments of cardiovascular and cerebrovascular diseases. Despite its commercial and medicinal values, few systematic studies on the metabolome of S. miltiorrhiza roots have been carried out so far. We systematically described the metabolic profiles of S. miltiorrhiza using high pressure liquid chromatography mass spectrometry (LC/MS) in conjunction with multivariate statistical analyses, aimed at monitoring their biological variations of secondary metabolites related to three locations and four S. miltiorrhiza genotypes. A total of 40 bioactive constituents were putatively annotated in S. miltiorrhiza root samples. This study found that both the same S. miltiorrhiza genotype growing at three different locations and four S. miltiorrhiza genotypes growing at the same location had significant metabonomic differences identified by the principal component analysis (PCA) approach. By using orthogonal projection to latent structure with discriminant analysis (OPLS-DA), 16 and 14 secondary metabolites can be used as potential location-specific and genotype-specific markers in S. miltiorrhiza, respectively. The specificity of LC/MS profiles offered a powerful tool to discriminate S. miltiorrhiza samples according to genotypes or locations.

The Influence of Cultivars and Phenological Phases on the Accumulation of Nevadensin and Salvigenin in Basil {Ocimum basilicum)

According to the earlier literature the optimum harvest time for basil is at the full flowering stage if accumulation of essential oil is taken into account. In this research we have investigated our gene-bank stored basil accessions to determine whether the harvest timing is variety specific or not considering their flavonoid accumulation pattern. In our work we have determined by HPLC the content of two main flavonoid compounds, salvigenin and nevadensin, of eight different gene bank accessions from 2013 of Ocimum basilicum L. Data were analysed with the nonparametric Kruskal-Wallis test. Multiple pairwise comparisons were made using the Conover-Iman procedure where the significance level was 5%. We have observed that the optimum harvest time is at the full flowering stage in the case of accessions ‘Genovese’ and ‘Piros’, but this was not verified for the others. The result of our experiment has shown that the maximum salvigenin and nevadensin content was detected both at the full- and early flowering period. Almost in all phenological phases the accession ‘M. Grimes’ accumulated the highest level of nevadensin, while accession ‘Lengyel’ produced the lowest results in all phenological phases. Generally it could be observed that compared with nevadensin more salvigenin is accumulated, and it is independent of the phenological phases. In the case of salvigenin, ‘M. Grimes’ accession produced the largest quantity and accession ‘Dark Opal’ showed the lowest values. Our analyses demonstrated that harvest at different phenological phases may result in different amounts of active agents according to the cultivar.

Basil Downy Mildew (Peronospora belbahrii): Discoveries and Challenges Relative to Its Control

Basil (Ocimum spp.) is one of the most economically important and widely grown herbs in the world. Basil downy mildew, caused by Peronospora belbahrii, has become an important disease in sweet basil (O. basilicum) production worldwide in the past decade. Global sweet basil production is at significant risk to basil downy mildew because of the lack of genetic resistance and the ability of the pathogen to be distributed on infested seed. Controlling the disease is challenging and consequently many crops have been lost. In the past few years, plant breeding efforts have been made to identify germplasm that can be used to introduce downy mildew resistance genes into commercial sweet basils while ensuring that resistant plants have the correct phenotype, aroma, and tastes needed for market acceptability. Fungicide efficacy studies have been conducted to evaluate current and newly developed conventional and organic fungicides for its management with limited success. This review explores the current efforts and progress being made in understanding basil downy mildew and its control.

Chemometrics: A new scenario in herbal drug standardization

Chromatography and spectroscopy techniques are the most commonly used methods in standardization of herbal medicines but the herbal system is not easy to analyze because of their complexity of chemical composition. Many cutting-edge analytical technologies have been introduced to evaluate the quality of medicinal plants and significant amount of measurement data has been produced. Chemometric techniques provide a good opportunity for mining more useful chemical information from the original data. Then, the application of chemometrics in the field of medicinal plants is spontaneous and necessary. Comprehensive methods and hyphenated techniques associated with chemometrics used for extracting useful information and supplying various methods of data processing are now more and more widely used in medicinal plants, among which chemometrics resolution methods and principal component analysis (PCA) are most commonly used techniques. This review focuses on the recent various important analytical techniques, important chemometrics tools and interpretation of results by PCA, and applications of chemometrics in quality evaluation of medicinal plants in the authenticity, efficacy and consistency.

Application of chemometrics in authentication of herbal medicines: a review

INTRODUCTION

Herbal medicines (HM) and their preparations have been widely used for hundreds of years all over the world. However, they have not been officially recognised due to a lack of adequate or accepted research methodology for their evaluation.

OBJECTIVE

To present a concise overview of the recent applications of chemometrics in solving the ambiguity of herbal medicine authentication during the last two decades.

METHODOLOGY

Studies involving the applications of chemometric analysis in combination with different analytical methods were classified according to the method of analysis used including chromatographic (HPLC, GC and CE), spectroscopic (NMR, IR, UV and ICP) and genetic analysis (RAPD). The purpose of each of these studies was classified into one of three main categories: taxonomic discrimination, quality assessment or classification between plants of different geographic origins.

RESULTS

This review comprises over 150 studies, covering the past two decades, emphasising the significance of chemometric methods in the discrimination of many herbs from closely related species and from adulterants, based on the principal bioactive components and phytochemical diversity. Furthermore, the differentiation between varieties and hybrids was achieved in addition to the prediction of the active components by quantitative methods of analysis. Discrimination according to geographical origin and localities, processing methods, DNA profiling and metabolomics were also efficiently investigated.

CONCLUSION

Chemometric methods have provided an efficient and powerful tool for the quality control and authentication of different herbs.

The chemical composition and antioxidant activities of basil from Thailand using retention indices and comprehensive two-dimensional gas chromatography

The chemical compositions of essential oils obtained from Ocimum basilicum var. thyrsiflora (1.39 % dry weight) and Ocimum basilicum (0.61 %) were analyzed by GC-MS. Seventy-three constituents representing 99.64 % of the chromatographic peak area were obtained in the O. basilicum var. thyrsiflora oil, whereas 80 constituents representing 91.11 % observed in the essential oil of O. basilicum were obtained. Methyl chavicol (81.82 %), ?-(E)-ocimene (2.93 %) and ?-(E)- bergamotene (2.45 %) were found to be the dominant constituents in O. basilicum var. thyrsiflora oil while O. basilicum contained predominantly linalool (43.78 %), eugenol (13.66 %) and 1,8-cineole (10.18 %). The clear separation of the volatiles in all samples, demonstrated by the application of GC?GC, resulted in significantly different fingerprints for the two types of basil. The O. basilicum oil showed strong antioxidant activity while the oil of O. basilicum var. thyrsiflora exhibited very low activity, which was attributed to the significant differences in linalool and eugenol contents in these essential oils.

Flavonoids of zoysiagrass (Zoysia spp.) cultivars varying in fall armyworm (Spodoptera frugiperda) resistance

Flavonoid profiles of 12 zoysiagrass (Zoysia spp.) cultivars sampled six times in 1998 were correlated to fall armyworm (Spodoptera frugiperda J. E. Smith) larval weights and survival on replicated field-grown plant material and analyzed to determine genetic and seasonal variations of flavonoids among zoysiagrass cultivars. From multiple regression analyses and correlations, flavonoid peak 10 (luteolin-glucoside) had the greatest positive association with average fall armyworm weight; however, resistance appeared to be correlated with a number of other flavonoids. The flavonoid profiles of cultivars subjected to clustering procedures showed consistent genetic variability for five of six samplings and was used to genotype 23 cultivars. The dendrogram supported the results of the FASTCLUS procedure in clustering certain genotypes such as fall armyworm-resistant Cavalier and Zeon together, as well as J-36 and Meyer. Flavonoid evaluations measure genetic relatedness among cultivars and could be used for selective breeding of resistance to fall armyworm.

Hydroxylated polymethoxyflavones and methylated flavonoids in sweet orange (Citrus sinensis) peel

Polymethoxyflavones (PMFs) from citrus genus have been of particular interest because of their broad spectrum of biological activities, including antiinflammatory, anticarcinogenic, and antiatherogenic properties. There have been increasing interests in the exploration of health beneficial properties of PMFs in citrus fruits. Therefore, the isolation and characterization of PMFs from sweet orange (Citrus sinensis) peel will lead to new applications of the byproducts from orange juice processes and other orange consumption in nutraceutical and pharmaceutical products. In our study, eight hydroxylated PMFs, six PMFs, one polymethoxyflavanone, one hydroxylated polymethoxyflavanone, and two hydroxylated polymethoxychalcones were isolated from sweet orange peel and their structures were elucidated by various MS, UV, and different NMR techniques. Some of the hydroxylated PMFs and chalcones are newly isolated from sweet orange peel.