Plants produce a diverse range of bioactive molecules making them rich source of different types of medicines

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Plants produce a diverse range of bioactive molecules making them rich source of different types of medicines. Various techniques are employed for their investigation which includes bioassays for chemical screening and their evaluation for the presence of biological activities. Isolation of pure pharmaceutically active constituents from plants remains a long tedious process. Chemical screening is performed to target isolation of new or useful type of constituents having potential activities. This procedure enables recognition of known metabolites in extracts in the earliest stages of separation and thus, is economically very important.
Tarenna asiatica (belonging to the family Rubiaceae) is a small thornless evergreen shrub growing to a height of 1-6m. It is a flowering plant mainly found in the Western Ghats and Hilly regions of India. The morphology of plant can be described by fragrant-stalkless-cream or yellow coloured corymb/chime like flowers, fruits containing two celled berries having many seeds and elliptical or elliptically-ovate leaves having dark green upper surface and paler beneath. It’s an herbal plant used in Siddha medicine, where its usage is applicable as antimicrobial, antifungal, antibacterial, anti-inflammatory and having analgesic properties. It is used in the treatment of many skin diseases and injuries. The paste of the leaves is applied for healing wounds whereas crushed fruits are applied to boils to promote suppuration (i.e., pus formation). 9, 10
All these pharmacological activities of the Tarenna asiatica has been studied in its previous research work using different plant parts and research models/methods 4, 5, 6, 7, 8. However, the active constituents relating to the pharmacological effects haven’t been investigated, current work deals with the extraction, separation, isolation, identification and characterization of different phytoconstituents present. This information may help in development of synthetic pharmaceuticals of the active phytoconstituents resulting in enhanced pharmacological activity.
The research work begins with complete extraction via Soxhlet apparatus of Tarenna asiatica leaves using ethanol as the solvent of choice, next preliminary phytochemical screening tests of the ethanolic extract revealed the presence of alkaloids, carbohydrates, volatile oils, flavonoids, glycosides, tannins, steroids and triterpenoids as listed in Table.1
The separation of constituents was done using TLC and HPTLC methods based on their Rf values obtained which were 0.07, 0.15, 0.35, 0.64, 0.78, 0.92, 0.97 and 0.01, 0.16, 0.59, 0.73, 0.77, 0.95 respectively.
FTIR analysis of ethanolic leaf extract of Tarenna asiatica resulted in identification of different functional groups present determined from the peaks obtained. The peak values were 2975.87, 1921.89, 1661.93, 1487.37, 1142.37, 1142.35, 1088.90, 1044.51, 878.49, 695.19, 577.07, 553.28, 534.10 and 513.18; which constitutes for the following functional groups such as alkanes, alkenes, aromatic alkenes, alkyl halides, alcohols, Si-OR, S-OR, C-Cl, C-Br and S-S (disulphides) as listed in Table.4
1H NMR lead to the determination of nature of protonated compounds in the sample showing peaks at 4.8574, 3.6234, 3.6058, 3.5882, 3.5706, 3.3078, 3.3038, 3.2997, 3.2957, 3.2917, 1.1864, 1.1688 and 1.1521 which helped in the identification of following proton constituents such as R-CH=C, -C-CH-OR, -C-CH-OH, C-CH2-O-R, C-CH2-OH, CH3-O-R, CH3-OH, CH3-C-NR2, CH3-C-CO-R and CH3-C-CHO as listed in Table.5
Final determination for the identification of different phytochemical constituents present in ethanolic leaf extract of Tarenna asiatica was done using GC-MS. The results pertaining to GC-MS analysis helped in recognition of compounds such as benzaldehyde, glycerine, benzofuran-2,3-dihydro-, propane-1,3-diol 4-methyl-benzeneboronate, n-hexadecanoic acid, phytol, D-mannitol, propylene glycol monoleate and squalene as listed in Table.6. Thus, the compounds obtained were matched with National institute of Standard Technology, NIST library.