Evaluation of chemical compositions and biological activities of Dendrobium species.

Dendrobium spp. were investigated for their chemical compositions with HPTLC/CMS, and biological properties, including antioxidant activities (DPPH and ABTS.+ assay), and anti-acetylcholinesterase (AChE). The ethanolic extracts of Dendrobium orchid pseudobulbs (D. chrysotoxum; DC, D. fimbriatum; DF, D. lindleyi; DL, and D. pulchellum; DP) were found to contain caffeic acid, gallic acid, quercetin, rutin hydrate and vanillin. While luteolin was shown in D. fimbriatum and D. lindleyi extracts. D. lindleyi, and D. pulchellum extracts presented the high value of total phenolic and flavonoid contents, resulting in a strong antioxidant property. Moreover, D. chrysotoxum extract expressed AChE inhibitory potential. This research indicated that chemical compounds in Dendrobium would be involved with their biological properties, i.e. antioxidant and anti-AChE. This information can be used to support further in-depth research and product development in health, food, and pharmaceutical.

Pharmaceutical Potential Evaluation of Damask Rose By-Products from Volatile Oil Extraction.

Despite its well-known fragrance in cosmetics and medicine, a complete understanding of the phytochemical properties within by-products generated during commercial extraction of Damask rose remains elusive. Cultivated in Thailand for their essential oil, Damask rose varieties, including Mon Dang Prasert, Mon Klai Kangwon, and Bishop's Castle, share phenylethyl alcohol (57.62-61.11%) as the dominant component, which is responsible for their characteristic floral, sweet, rosy, and bready aroma. Through a circular hydro-distillation process, three different by-product fractions, including distilled water (D), hydrosol (H), and rose dreg (R), were recovered. Subsequently, we assessed their pharmaceutical potential, including the antioxidant, antimicrobial, anti-inflammatory, and anti-melanogenesis properties of these residual substances. The H fraction displayed the highest total phenolics (10.56 mgGAE/g) and flavonoids (6.93 mgCE/g) and significant antioxidant activity (IC50, 0.67-0.97 µg/mL). While the H fraction inhibited melanin formation at 50 µg/mL, the R fraction of MK (100 µg/mL) surprisingly promoted melanin production in B16-F10 cells. Nevertheless, the antimicrobial assay against Staphylococcus aureus, Cutibacterium acnes, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans revealed no antimicrobial activity in any fraction. Murine macrophage stimulation (J774A.1) with lipopolysaccharide revealed no anti-inflammatory effects from the by-products, as measured by IL-1ß production. In summary, the H fraction exhibited the highest level of phenolic and flavonoid contents, as well as antioxidant and anti-melanogenesis activities. Therefore, this by-product is a desirable choice for the development of value-added products such as functional food, cosmetics, and pharmaceutical products.

Phytochemical analysis, antioxidant, and anticholinesterase activities of ethanolic extracts from five ginger plants in Thailand.

Five selected medicinal plants in the family Zingiberaceae, Alpinia nigra, Boesenbergia maxwellii, Etlingera araneosa, Meistera koenigii, and Wurfbainia biflora, were collected from Thailand. HPLC was used to determine the content of phenolic compounds in their ethanolic extracts. The total phenolic contents and the total flavonoid contents of M. koenigii were found to be higher than that of the others. The antioxidant activity of the extracts was assayed by two methods, namely ABTS and DPPH assays using HPTLC and a microplate spectrophotometer. Anticholinesterase activity was screened by the Ellman method against acetylcholinesterase, the chief enzyme of Alzheimer's disease. The results showed mild acetylcholinesterase effects. The results indicated that these five ginger species, especially M. koenigii have the potential to be a good source of natural antioxidants and anticholinesterase agents that could be further applied in the pharmaceutical industry.

Natural Surfactant Saponin from Tissue of Litsea glutinosa and Its Alternative Sustainable Production.

In this research, we assessed the detergency properties along with chemical characteristic of the surfactant extracts from the most frequently cited detergent plants in Northern Thailand, namely, Sapindus rarak, Acacia concinna, and Litsea glutinosa. Moreover, as to provide the sustainable option for production of such valuable ingredients, plant tissue culture (PTC) as alternative method for industrial metabolite cultivation was also proposed herein. The results illustrated that detergent plant extracts showed moderate in foaming and detergency abilities compared with those of synthetic surfactant. The phytochemical analysis illustrated the positive detection of saponins in L. glutinosa plant extracts. The highest callus formation was found in L. glutinosa explant cultured with MS medium supplemented with 2.0 mg/L Indole-3-acetic acid (IAA). The callus extract was chemical elucidated using chromatography, which illustrated the presence of saponin similar to those from the crude leaf and Quillaja saponin extracts. Compact mass spectrometry confirmed that the surfactant was of the steroidal diagnostic type.

The combination of ITS2 and psbA-trnH region is powerful DNA barcode markers for authentication of medicinal Terminalia plants from Thailand.

The dried fruits of Terminalia plant (Combretaceae) called "Samo" have been used as herbal medicine in Thai traditional medicine. Four "Samo" crude drugs, namely, Samo thai, Samo thed, Samo dee-ngu, and Samo phiphek, are used as the main ingredients in Triphala and Trisamo recipes. Their commercial products are available in processed and powdered form, but are difficult to authenticate by conventional methods. In this study, we aimed to discriminate species of genus Terminalia for the identification of their crude drugs by a DNA barcoding technique. A total of 208 closely related nucleotide sequences were obtained from nine Terminalia species collected from Thailand and the DDBJ/EMBL/GenBank database. An effective DNA barcode marker was selected from six DNA loci (matK, rbcL, psbA-trnH, ITS, ITS1, and ITS2) and their two-locus combination. All sequences were analyzed by three major methods: (1) BLAST search; (2) the genetic divergence method using Kimura 2-parameter (K2P) distance matrices; and (3) tree topology analysis based on the neighbor-joining method. Comparison of the six candidate DNA loci indicated that ITS identified Terminalia with 100% accuracy at the species and genus levels in the BLAST1 method. ITS2 showed the highest K2P variability. The data from the single markers and the two-locus combinations revealed that only the two-locus combinations, namely, the combinations of rbcL, ITS, ITS1, and ITS2 with psbA-trnH, clearly discriminated all the species. From the results of DNA sequence analysis and the three methods, ITS2 is recommended for the identification of Terminalia species to supplement psbA-trnH.

Nutritional Compositions and Phytochemical Properties of the Edible Flowers from Selected Zingiberaceae Found in Thailand.

The nutritional compositions and phytochemical properties of eight edible flowers of the ginger family (Zingiberaceae) commonly found in Thailand are reported herein. The plant genera investigated were Zingiber (Ginger, Phlai Dam, Krathue), Hedychium (two morphological filament forms), Curcuma (Ao), Etlingera (Torch ginger), Amomum (Chi Kuk), and Alpinia (Galangal), which are eaten fresh or cooked as ingredients in the preparation of many Thai dishes. The proximate compositions (moisture, ash, fiber, protein, fat, and carbohydrate contents) varied among the different genera. The plants sampled were generally low in fat content (<1%), which contributed as little as 30% of the total caloric energy. Edible plant parts contained substantially high amounts of potassium (max. 737.21 mg/100 g), calcium (max. 140.15 mg/100 g), and iron (~0.32 mg/100 g). Among the tested samples, torch ginger had the highest vitamin C content (1.05 mg/100 g), total phenolic and total flavonoid contents, as well as 2,2-diphenyl-1-picrylhydrazyl activity. On the other hand, the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay suggested that Hedychium species possessed the highest antioxidant activity (~5.38 mg TEAC/g extract). Our results prove that edible plants of the Zingiberaceae family found in Thailand are rich sources of potentially important nutrients.

Chemical composition and antibacterial activity of rhizome oils from five Hedychium species.

The essential oils from rhizomes of five Hedychium species, H. coronarium, H. neocarneum, H. flavescens, H. speciosum and H. stenopetalum (Zingiberaceae), were obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Sixty components were identified and percentage oil yields from the fresh plants ranged from 0.06-0.17 % (v/w). All rhizome oils were rich in terpenes, especially monoterpenes (75.0-95.9 %). The most common compounds in the rhizome oils of Hedychium were beta-pinene, linalool and 1,8-cineole. The essential oils were tested against four bacterial strains. They showed moderate to weak activity against Gram-positive bacteria (inhibition zone 25-13 mm, MIC 0.3-8.3 mg/mL, MBC 0.6-8.3 mg/mL).