Andrographolide and its derivatives: Current achievements and future perspectives.

Natural product andrographolide isolated from the plant Andrographis paniculata shows a plethora of biological activities, including anti-tumor, anti-bacterial, anti-inflammation, anti-virus, anti-fibrosis, anti-obesity, immunomodulatory and hypoglycemic activities. Based on extensive chemical structural modifications, a series of andrographolide derivatives with improved bioavailability and druggability has been developed. Moreover, greater understanding of their mechanisms of action at the molecular and cellular level has been thoroughly investigated. In this review, we give an outlook for the therapeutical potential of andrographolide and its derivatives in diverse diseases and highlighted the drug design, pharmacokinetic and mechanistic studies for the past ten years, together with a brief overview of the pharmacological effects. Notably, we focused to provide a critical enlightenment of the area of andrographolide and its derivatives with the intent of indicating the future perspectives, challenges and limitations. We believe that this review paper will benefit drug discovery where andrographolide was used as a template, shed light on the identification of drug targets for andrographolide and its analogs, as well as increase our knowledge for using them for therapeutic application, including the treatment for various forms of cancers.

Chemically Diverse and Biologically Active Secondary Metabolites from Marine Phylum chlorophyta.

For a long time, algal chemistry from terrestrial to marine or freshwater bodies, especially chlorophytes, has fascinated numerous investigators to develop new drugs in the nutraceutical and pharmaceutical industries. As such, chlorophytes comprise a diverse structural class of secondary metabolites, having functional groups that are specific to a particular source. All bioactive compounds of chlorophyte are of great interest due to their supplemental/nutritional/pharmacological activities. In this review, a detailed description of the chemical diversity of compounds encompassing alkaloids, terpenes, steroids, fatty acids and glycerides, their subclasses and their structures are discussed. These promising natural products have efficiency in developing new drugs necessary in the treatment of various deadly pathologies (cancer, HIV, SARS-CoV-2, several inflammations, etc.). Marine chlorophyte, therefore, is portrayed as a pivotal treasure in the case of drugs having marine provenience. It is a domain of research expected to probe novel pharmaceutically or nutraceutically important secondary metabolites resulting from marine Chlorophyta. In this regard, our review aims to compile the isolated secondary metabolites having diverse chemical structures from chlorophytes (like Caulerpa ssp., Ulva ssp., Tydemania ssp., Penicillus ssp., Codium ssp., Capsosiphon ssp., Avrainvillea ssp.), their biological properties, applications and possible mode of action.

High-Throughput Phenotyping of Fire Blight Disease Symptoms Using Sensing Techniques in Apple.

Washington State produces about 70% of total fresh market apples in the United States. One of the primary goals of apple breeding programs is the development of new cultivars resistant to devastating diseases such as fire blight. The overall objective of this study was to investigate high-throughput phenotyping techniques to evaluate fire blight disease symptoms in apple trees. In this regard, normalized stomatal conductance data acquired using a portable photosynthetic system, image data collected using RGB and multispectral cameras, and visible-near infrared spectral reflectance acquired using a hyperspectral sensing system, were independently evaluated to estimate the progression of fire blight infection in young apple trees. Sensors with ranging complexity - from simple RGB to multispectral imaging to hyperspectral system - were evaluated to select the most accurate technique for the assessment of fire blight disease symptoms. The proximal multispectral images and visible-near infrared spectral reflectance data were collected in two field seasons (2016, 2017); while, proximal side-view RGB images and multispectral images using unmanned aerial systems were collected in 2017. The normalized stomatal conductance data was correlated with disease severity rating (r = 0.51, P < 0.05). The features extracted from RGB images (e.g., maximum length of senesced leaves, area of senesced leaves, ratio between senesced and healthy leaf area) and multispectral images (e.g., vegetation indices) also demonstrated potential in evaluation of disease rating (|r| > 0.35, P < 0.05). The average classification accuracy achieved using visible-near infrared spectral reflectance data during the classification of susceptible from symptomless groups ranged between 71 and 93% using partial least square regression and quadratic support vector machine. In addition, fire blight disease ratings were compared with normalized difference spectral indices (NDSIs) that were generated from visible-near infrared reflectance spectra. The selected spectral bands in the range 710-2,340 nm used for computing NDSIs showed consistently higher correlation with disease severity rating than data acquired from RGB and multispectral imaging sensors across multiple seasons. In summary, these specific spectral bands can be used for evaluating fire blight disease severity in apple breeding programs and potentially as early fire blight disease detection tool to assist in production systems.