Insights from paclitaxel research inspire elucidation of hypericin biosynthesis, highlighting gene identification, multi-omics integration, and biotechnological strategies enabling scalable and sustainable production of valuable Hypericum secondary metabolites. Paclitaxel (Taxol®), a major plant-derived anticancer drug, exemplifies how research on complex natural products can lead to both breakthrough therapies and innovative strategies for scalable production. Building on this model, this review examines how advances in paclitaxel research have inspired new approaches to studying and producing other pharmaceutically important metabolites, particularly hypericins in Hypericum species. Complementary strategies, ranging from in vitro cultures and elicitor treatments to metabolomic and transcriptomic profiling, have shown promise in enhancing hypericin production, paralleling advances achieved with paclitaxel. Despite their known antiviral and anticancer properties, the biosynthetic pathway of hypericins remains only partially resolved. Current evidence supports a polyketide origin involving emodin and related intermediates, yet key enzymatic steps, particularly those leading to dimeric structures, are still unknown. Although candidate enzymes such as the polyketide synthase HpPKS2 have been identified in Hypericum species, much of the pathway remains unresolved. Given the biosynthetic parallels, fungal systems synthesizing related polyketide metabolites represent promising comparative models for elucidating the hypericin pathway and advancing metabolic engineering efforts. Insights derived from paclitaxel research may thus guide future strategies for elucidating, optimizing, and sustainably producing hypericins and other specialized metabolites across the genus Hypericum.

Hypericum sechmenii Ocak & O.Koyuncu (Seçmen's St John's wort) is a rare species of flowering plant in the St John's wort family that is found in Eskişehir Province in central Turkey. It was first described and assigned to the genus Hypericum L. in 2009, and was later placed into the section AdenosepalumSpach. H. sechmenii is a perennial herb that grows 3 to 6 centimeters (1 to 2 inches) tall and blooms in June and July. The stems of the plant are smooth and hairless, while the leaves are leathery and lack leafstalks. Its flowers are arranged in corymbs, and each has five bright yellow petals. Similar species are H. huber-morathiiRobson, H. minutumDavis & Poulter, and H. thymopsisBoiss.. Found among limestone rocks, H. sechmenii has an estimated distribution of less than 10 square kilometers (4 square miles), with fewer than 250 surviving plants. Despite containing druse crystals and toxic chemicals that may deter herbivory, the species is threatened by overgrazing, as well as climate change and habitat loss.

Hypericum bilgehan bilgilii is a locally endemic species belonging to the genus Hypericum. Considering that the related plant has pharmacological and medicinal potential like other Hypericum species, this study has been conducted to determine its physiological and antioxidant activities. Plant extracts obtained through three different cultivation methods (wild, cultivated in a laboratory environment in peat, and cultivated using tissue culture methods) were used to determine physiological, biochemical, and antioxidant activity analyses. (The abbreviations for the cultivation methods are indicated as, respectively, W, in vivo in lab, in vitro in lab). In this study, the highest photosynthetic pigment content, total protein content, proline content, malondialdehyde (MDA) content, phenylalanine ammonium lyase (PAL) activity, antioxidant activity (2,2-Diphenyl-1-picryl hydrazyl radical scavenging activity, total phenolic content, carotenoid) values were determined for the first time in the in vitro in lab group in H. bilgehan bilgilii plants grown under three different cultivation methods. Superoxide dismutase (SOD) and catalase (CAT) enzyme activities were observed at the highest levels in the wild group. Based on these parameters, the physiological, biochemical, and antioxidant activities of the H. bilgehan bilgilii plant were studied for the first time under different cultivation conditions, producing new results. According to these results, it was determined that in vitro cultivated plants have higher physiological parameters and antioxidant content. This study has also demonstrated the significance of tissue culture, a biotechnological method, in enhancing bioactive compounds, and that in vitro cultures could be used as an alternative to traditional methods for producing larger quantities of bioactive compounds. In addition, establishing in vitro cultures for endemic, endangered, and medically significant species will enable the sustainable use of the local endemic species H. bilgehan-bilgilii, facilitate large-scale production of phytochemicals, and provide a valuable plant resource and information for future comprehensive phytochemical studies.

IntroductionHypericum spp., particularly Hypericum perforatum (such as St. John’s Wort), produce hypericin and hyperforin, secondary metabolites that play critical roles in the plant’s defense mechanisms. These compounds, characterized by their polycyclic and lipophilic properties, have evolved to deter herbivores and protect against pathogens. Understanding the evolutionary pressures that shaped these compounds enhances our knowledge of their biochemical roles.ObjectivesThis review aims to synthesize current knowledge on the evolutionary development of hypericin and hyperforin within the Hypericum genus, focusing on how these metabolites evolved to fulfill defensive ecological functions.MethodsA comprehensive literature review was conducted, examining phylogenomic studies, structural analyses, and biochemical research related to the biosynthesis of hypericin and hyperforin. We reviewed relevant phylogenetic data to understand the diversification of these compounds across Hypericum spp.ResultsThe literature supports that hypericin and hyperforin evolved in response to selective pressures during the Cretaceous-Paleogene boundary, with their complex polycyclic aromatic structures optimized for defense. These structures, which include conjugated π-systems, are central to the compounds’ ability to deter herbivores and resist pathogens, reflecting an evolutionary adaptation that is conserved across the genus.ConclusionsThe evolution of hypericin and hyperforin within Hypericum spp. is a prime example of how secondary metabolites serve dual purposes in nature and human use. The phylogenetic and biochemical insights reviewed highlight the importance of these compounds as both ecological defenses and pharmacologically active agents.Disclosure of InterestNone Declared

The limited data on biological potential of the genus Hypericum sect. Drosocarpium species initiated the current research aimed at the chemical characterization of samples of six selected taxa (H. barbatum, H. montbretii, H. richerii subsp. grisebachii, H. rochelii, H. rumeliacum, and H. spruneri) and the evaluation of their biological potential (antioxidant and antihyperglycaemic potential, acetylcholinesterase and monoamine oxidases inhibition). The obtained results suggest greater abundance of biologically active compounds, hypericin (H. rochelii, H. barbatum, and H. richerii subsp. grisebachii), amentoflavone (H. richerii subsp. grisebachii), quercetin and rutin (H. richerii subsp. grisebachii), and chlorogenic acid (H. richerii subsp. grisebachii, H. barbatum, H. rumeliacum), when compared to H. perforatum. Also, the scavenging potential of DPPH (median RSC50 = 3.34 µg/mL), NO (median RSC50 = 26.47 µg/mL) and OH radicals (median RSC50 = 76.87 µg/mL) of evaluated species was higher, or at least comparable to H. perforatum, while the same trend was noticed in the case of anti-MAO-A (median IC50 = 19.41 µg/mL) and antihyperglycaemic potential (inhibition of α-amylase and α-glucosidase (median IC50 = 29.47 µg/mL)). The study results highlight sect. Drosocarpium species as a valuable source of biologically active secondary metabolites and suggest a wide spectrum of possible applications in the food and medicine industries.

Hypericin, a polycyclic aromatic naphthodianthrone, is derived from the Hypericum genus and acts as a photosensitizer in the photodynamic therapy of numerous cancers. However, the mechanism of hypericin against skin cancer is not yet investigated. In the present study, the fruit flies were classified into six groups: Group I- control, Group II- UVC treated, Group III, IV, V and VI- UVC treated along with hypericin (0.1%, 0.2%, 0.4% and 0.8% respectively) exposed. Following the treatment, the climbing activity was assessed. Based on the behavioural study, 0.4% of hypericin was considered as an active dose and utilized for further experiments (Group I- Control; Group II- UVC exposed; Group III- UVC + Hypericin (0.4%); and Group IV- Hypericin (0.4%) alone). The levels of protein carbonyl content and thiobarbituric acid reactive substances were enhanced significantly (p<0.05) in hemolymph and diminished significantly (p<0.05) in the head and intestine of UVC-exposed D. melanogaster. The levels of GSH and the activities of SOD, GST, catalase and GPx were diminished significantly (p<0.05) in the circulation and tissues of UVC-exposed flies. Hypericin treatment significantly (p<0.05) nullifies the oxidative imbalance exerted by UVC and brings them back to near normal levels. Behaviour study is also supported the present findings. Further molecular research is needed to know the mechanism of action of hypericin and improve the fly model to utilize it for translational research, targeting to link the gap between preclinical findings and clinical studies.

Phytochemical diversity and biological activities of Hypericum japonicum and Hypericum sampsonii: potential for natural product-based food applications.

Carotenoid, chlorophyll and tocochromanol biosynthesis and accumulation are interrelated and age-dependent in plants. Model plants produce tocopherols, but do not produce significant amounts of tocotrienols; consequently, the regulation of tocotrienol biosynthesis in plants has been scarcely studied. The Hypericum genus produces a variety of prenyllipids naturally in all parts of the plant, allowing for a glimpse into the relationship between them without genetic or other interference. Consequently, five Hypericum species’ leaves of different ages were investigated—H. androsaemum, H. pseudohenryi, H. hookerianum, H. patulum and one hybrid H. × inodorum (H. androsaemum × H. hircinum). The leaves contained predominantly α-tocopherol, γ-tocotrienol and δ-tocotrienol (30.9–212.8, 8.13–22.43 and 1.87–20.8 mg 100 g−1, respectively). Higher quantities of tocochromanols, a lower chlorophyll content and a higher a/b ratio were observed in the bottom (older) leaves. The predominant carotenoids were lutein (semi-quantitative) and β-carotene (7.60–28.63 and 2.33–12.43 mg 100 g−1, respectively). Carotenoid contents were lower in bottom leaves than in middle or top leaves, and the highest carotenoid content was observed in H. hookerianum and H. patulum. Leaf tocopherol, tocotrienol, chlorophyll and carotenoid accumulation were section and leaf age-dependent, and distinct relationships can be observed between the accumulation of some prenyl lipids, but not others.

α-Tocopherol (α-T) predominates in photosynthetic tissues, while tocotrienols (T3s) are reported very rarely. The genus Hypericum stands out as one of the few exceptions. Given the potential health benefits associated with tocotrienols, sourcing them from natural origins is of interest. The proper selection of plant material and the drying conditions are crucial steps in this process. Therefore, in the present study, we investigated the effects of four different drying techniques (freeze-drying, microwave-vacuum-, infrared oven and air-drying) on the tocochromanol content in leaves of three Hypericum species: H. androsaemum, H. pseudohenryi, and H. hookerianum and one hybrid H. × inodorum. The total tocochromanol content in the freeze-dried leaves harvested in September was 68.1-150.6 mg/100 g dry weight. α-T constituted 66.7-85.9% (w/w), while tocotrienols constituted 13-32% (w/w). H. pseudohenryi was characterized by the lowest tocotrienol content, while H. androsaemum and H. hookerianum had the highest, with δ-T3 and γ-T3, respectively, being predominant. Tocotrienols were more stable during drying than α-T. The greatest decrease in α-T content was observed during air-drying in the presence of sunlight, with a 27% difference compared to the absence of sunlight. The species and harvest time are factors that more strongly affect the tocotrienol content in the Hypericum leaves than the selected drying method.

This study investigates the phytochemical composition and biopharmacological potential of three Hypericum species (H. scabrum, H. lysimachioides, and H. uniglandulosum) from Turkey. Aqueous and hydroalcoholic extracts were analyzed for their total phenolic content (TPC), total flavonoid content (TFC), and individual components (by the UHPLC-HRMS technique). Antioxidant activities were investigated by DPPH, ABTS, CUPRAC, FRAP, phosphomolybdenum, and metal chelating assays. The inhibition effects of the tested extracts on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase were examined. One hundred compounds were identified in the chemical composition, and specific compounds for the genus Hypericum, such as hyperoside, hypericin, and pseudohypericin, were detected. The highest TPC was detected in the ethanol/water extract of H. lysimachioides with 69.21 mg GAE/g. Furthermore, the ethanol/water extract showed the strongest free radical and reducing effect. The ethanol/water extracts of the tested Hypericum species were more active in tyrosinase, amylase, and glucosidase than the water extracts. Neuroprotective assessments indicated downregulation of COX-2 and NOS-2 genes in LPS-stimulated mouse cortex models, alongside modulation of SERT and NET expression, suggesting reduced neuroinflammation and enhanced neurotransmitter release. Molecular docking and dynamics analyses highlighted strong binding interactions, especially in the NET_hyperoside and NET_myricitrin complexes. The results indicate significant therapeutic potential for these extracts, supporting their development as natural agents against oxidative stress, neuroinflammation, and related neurodegenerative diseases.

The Hypericum genus is significant both medically and economically due to its bioactive compounds. This study utilized plant biotechnology techniques to develop an efficient and reliable adventitious shoot regeneration and suitable cell suspension culture system for various Hypericum species, including Hypericum perforatum L., Hypericum leptophyllum Hochst, Hypericum heterophyllum L., Hypericum humifusum L., and Hypericum athoum Boiss. & Orph. High frequency of callus induction using leaf explants on MS medium containing 1.0 mg/L BAP and 0.1 mg/L 2,4-D for Hypericum perforatum L. (100%), Hypericum humifusum L. (90%), and Hypericum leptophyllum Hochst (90%). The best shoot regeneration was also achieved in Hypericum humifusum L. (86.3%), Hypericum perforatum L. (73.0%), Hypericum leptophyllum Hochst (45.67%) and Hypericum athoum Boiss. & Orph. (18.33%) on MS medium with 1.0 mg/L BAP and 0.1 mg/L 2,4-D. Calli clusters obtained on callus induction medium were cultured on cell suspension culture MS basal media with B5 vitamins containing 2 mg/L glycine, 1 mg/L 2,4-D, 0.1 mg/L KIN, and 0.1 mg/L BAP. The friable calli developed in the suspension culture and plated on the medium. The proembryogenic structures formed turned to embryonic structures. These globular embryos further transformed into heart and cotyledonary stage and germinated. The maximum number of shoot/callus or percentage of germination of somatic embryo were respectively recorded for H. perforatum L. (15.37/callus), H. leptophyllum Hochst (6.9/callus), H. heterophyllum L. (9.6/callus), H. humifusum L. (16.8/callus) and H. athoum Boiss. & Orph. (11.7/callus). H. perforatum L. and H. humifusum L. showed the best shoot regeneration capacity as recorded in adventitious shoot regeneration studies. The plants were acclimatized with 85-100 % survival rat, H. perforatum and H. humifusum L. had also the highest survival rate (100%) as having regeneration capacity.

The genus Hypericum is a widely distributed ornamental and therapeutic herb known for its diverse bioactive compounds, including xanthones. The levels of secondary metabolites in plants are influenced by the specific plant part, agronomic conditions, and environmental factors. Recently, the occurrence of tocotrienols, rare tocochromanols, was reported in Hypericum perforatum. Therefore, this study investigated the profiles of tocochromanols in different plant sections—leaves, stems, flowers, and flower bud—of four Hypericum species: H. perforatum, H. annulatum, H. androsaemum, and H. × inodorum, cultivated in three types of soil: potting, sandy, and clay. In the initial growing year, the highest biomass yield was recorded for H. perforatum grown in potting soil. Soil and species significantly influence biomass yield (p < 0.05). The inflorescences of H. perforatum were dominated by tocotrienols (T3s), primarily α-T3 and δ-T3, an observation not noted for H. annulatum. α-Tocopherol (α-T) was dominant in the leaves, while in the stems, except for H. perforatum (α-T), tocotrienols—γ-T3 and δ-T3 in H. inodorum and H. androsaemum and α-T3 and γ-T3 in H. annulatum—were more prevalent. This study demonstrates differences in tocochromanol accumulation in different parts of the four Hypericum species grown in different soils.

Abstract Therapeutic potential of Hypericum oblongifolium from the biodiverse Himalayan region has not been widely reported. It is part of the Hypericum genus inhabiting the Western and Northern Himalayas. This work was aimed at extracting and analysing the chemical composition of essential oil (EO) from leaves of H. oblongifolium Wall. found in the Solan district of Himachal Pradesh in India. The EO content in the leaves of the H. oblongifolium was found to be 0.3% ± 0.07 v/w fresh weight. Gas chromatography-mass spectroscopy (GC-MS) analysis of H. oblongifolium EO or HOEO led to the identification of ten major compounds. Caryophyllene (18.97%) was the major constituent in HOEO, followed by α-pinene (18.79%) and α-cuprenene (17.59%). Both caryophyllene and α-cuprenene are a class of sesquiterpene. Caryophyllene has properties that can support the immune system, alleviate pain, with ability to work as an anti-inflammatory agent. α-Cuprenene is another potent terpene bio-factory with several medicinal properties. Further, α-pinene belongs to the terpene class of organic compounds with potent antimetastatic and apoptotic properties. This is the first report on the extraction of EO from H. oblongifolium . The properties of HOEO make it an ideal candidate for potential applications as a conventional drug alternative and in the cosmetic industry for its fragrance.

Now under Clusiaceae and Hypericaceae, Clusia and Hypericum were previously categorized under one family until they were divided in 2003 by the APG III system. The Clusia genus is characterized by the presence of tocotrienol derivatives with antiangiogenic properties, and only Hypericum perforatum tocochromanol content has been studied in the Hypericum genus. Twelve species were analyzed: H. aegypticum, H. calycinum, H. empetrifolium, H. lancasteri, H. olympicum f. minus 'Sulphureum', H. perforatum, H. xylosteifolium, C. fluminensis, C. minor, C. odorata, C. palmicida, and C. tocuchensis. Plant leaves were analyzed for their tocochromanol (α-, β-, γ-, and δ-tocotrienol and tocopherol) contents using a reverse-phase high-performance liquid chromatography with fluorescent light detector (RP-HPLC-FLD) method. While α-tocopherol (α-T) was present in the highest proportion, the leaves had significant tocotrienol (T3) contents. Following α-T, δ-T3 was present in most Clusia samples, and γ-T3 in most Hypericum samples, except H. olympicum, in which α-T3 followed. C. minor had the highest α-T (112.72 mg 100 g-1) and total tocochromanol (141.43 mg 100 g-1) content, followed by C. palmicida (65.97 and 82.96 mg 100 g-1, respectively) and H. olympicum (α-T 32.08, α-T3 30.68, and total tocochromanols 89.06 mg 100 g-1). The Hypericum genus is a valuable source of tocotrienols, with potential use after purification.

Türkiye is considered one of the major centers of diversity for the genus Hypericum (Hypericaceae). In this study, the volatile compositions of above ground parts of seven Hypericum taxa growing wild in Türkiye (H. alacamdaglariense, H. empetrifolium subsp. empetrifolium, H. microcalycinum, H. montbretii, H. olympicum subsp. olympicum, H. perforatum and H. scabroides) were investigated. Microdistillation and/or hydrodistillation were performed to obtain volatile compounds, and subsequently analyzed by GC and GC/MS. In total, 128 and 120 different compounds were identified by micro- and hydrodistillation, respectively. Monoterpene- and sesquiterpene hydrocarbons were abundant, followed by n-alkanes and oxigenated sesquiterpenes. The phytochemical data were evaluated using principal component analysis and hierarchial cluster analysis which exposed the contribution of compounds to the overall chemodiversity and revealed key compounds that help discrimination of the samples. This study also presents the first report on the volatile composition of H. alacamdaglariense, one of the most recently identified Hypericum species in Türkiye.

Saint John's worts or goatweeds are mostly perennial flowering plants in the Hypericaceae family, formerly under the Clusiaceae family. Teas and macerations of the plants are common in traditional medicines and modern depression and cancer therapies. The most notable bioactive compounds in Hypericum are hyperforin and hypericin. While Hypericum contains a variety of carotenoid and phenolic compounds, which are well documented, there is little available information on tocopherols and almost none on tocotrienols. Considering the frequency of tocotrienol derivatives in Clusiaceae species, this study investigates and reports the presence of tocotrienols in eleven Hypericum species' leaves: H. hircinum, H. hookerianum, H. calycinum, H. xylosteifolium, H. densifolium, H. prolificum, H. kalmianum, H. frondosum, H. olympicum, and two hybrids: H. × moserianum and H × 'Rowallane'. Eight tocopherol and tocotrienol forms (α, β, γ, δ) were detected in the leaves, predominantly containing α-tocopherol. Tocotrienol content was most significant in Myriandra section species and was highest in H. prolificum (22.90 ± 0.63 mg 100 g-1), while the highest tocotrienol proportion was observed in H. × 'Rowallane' (54.12% of total tocochromanols) and H. prolificum (37.27% of total tocochromanols). The results demonstrated significant tocochromanol accumulation in Hypericum leaves.

The genus Hypericum (Hypericaceae), comprising approximately 500 taxa classified into 22 sections, has remained largely unexplored in terms of its chemical composition, with existing studies on a limited number of species revealing significant chemical polymorphism. This study investigates the volatile profiles of four Hypericum species (H. rumeliacum subsp. apollinis, H. vesiculosum, H. delphicum, and H. olympicum) through GC-MS analysis. Hypericum rumeliacum subsp. apollinis, collected from Mt. Parnassos, exhibited a high abundance of sesquiterpenes hydrocarbons (32.5%) and oxygenated sesquiterpenes (29.7%). Hypericum vesiculosum collected from Mt. Chelmos was rich in oxygenated monoterpenes (33.5%), followed by benzyl derivatives (25.9%). Hypericum delphicum and H. olympicum, collected from the island of Evvia, showed a predominance of alkanes (35.8%) and oxygenated sesquiterpenes (31.9%) in H. delphicum and sesquiterpenes hydrocarbons (41.2%) and oxygenated sesquiterpenes (29.9%) in H. olympicum. Our findings provide new data on the volatile profile of H. vesiculosum and enhance existing information on other species, highlighting notable chemical diversity within the genus Hypericum.

St. John's wort (Hypericum perforatum, Hypericaceae) is the most well-known species in the genus Hypericum, which comprises several hundred species. This study investigates the biological and phytochemical potential of the under-researched Hypericum species, H. hirsutum, H. barbatum, and H. rochelii. A high level of similarity between the chemical profiles of H. hirsutum and H. barbatum and the official source of the herbal drug (H. perforatum) was shown, but a higher content of quercetin and rutin was also found in all three evaluated species (116-230 µg/g dry herb). The highest amount of phenolics (195 mg GAE/g) was recorded in H. hirsutum extract, while the highest amount of flavonoids (47 mg QE/g) was recorded in H. barbatum extract. The evaluated species were excellent scavengers of DPPH, OH, and NO radicals, as well as strong ferric ion reducers in the FRAP test. Prominent monoamine oxidase A and α-glucosidase inhibition was observed, compared to modest inhibition of monoamine oxidase B, α-amylase, and acetylcholinesterase. High activity against Gram-positive MRSA S. aureus was demonstrated for the tested species, with MIC/MBC values recorded at 12.5 µg/mL. Antifungal activity against Candida strains was not observed. The obtained results emphasize the need for further investigation of species of the genus Hypericum to discover potentially new sources of biologically active compounds.

The column chromatography with silica gel, reversed-phase C_(18), and Sephadex LH-20 was employed to separate the methanol extract of the aerial parts of Hypericum elatoides. The compounds were identified by the comprehensive analysis of IR, NMR, and MS data as methyl 8-O-β-D-glucopyranosyl-(Z)-5-octenoate(1), methyl 3-O-β-D-glucopyranosyl-4-methylhexanoate(2), byzantionoside B(3), 9-epi-blumenol C glucoside(4), corchoionoside C(5),(6S,9R)-roseoside(6), cis-p-coumaric acid 4-O-β-D-glucopyranoside(7), trans-p-coumaric acid 4-O-β-D-glucopyranoside(8), methyl 3-(4-hydroxyphenyl)propanoate(9),(E)-chlorogenic acid methyl ester(10), quercetin-3-O-β-D-glucopyranoside(11), β-sitosterol(12), stigmasterol(13), stigmast-4-en-3-one(14), β-amyrin(15), daucosterol(16), sitoindoside Ⅰ(17), oleic acid(18), methyl α-linolenate(19), trilinolein(20), and cassipourol(21). Among them, compounds 1 and 2 were identified as new glycosides and named hyperelatosides G and H. Compounds 3-5, 7-9, 17, and 20-21 were isolated from the genus Hypericum for the first time. The remaining compounds were isolated from H. elatoides for the first time. The results of biological assays revealed that compound 11 exhibited significant anti-neuroinflammatory activity, and compounds 1, 3, and 19 displayed certain neuroprotective effects.

The genus Hypericum comprises a large number of species. The flower, leaf, stem, and root of the Hypericum species are widely used in traditional medicine in different cultures. Many Hypericum species have been well investigated phytochemically and pharmacologically. However, only a few reports are available on the H. cordifolium native to Nepal. The present study aims to evaluate the phytochemical composition of different extracts, qualitative analysis of methanol extract of the flower and leaf using thin-layer chromatography (TLC), and the antioxidant properties of components by the TLC-DPPH. assay. The phenolic and flavonoid contents were estimated in different extracts of the leaf and stem, and their antioxidant and antibacterial activities were evaluated. In the phytochemical screening, phenolics and flavonoids were present in ethyl acetate, methanol, and 50% aq methanol extracts of both the leaf and stem. In TLC analysis, the methanol extract of flowers showed the presence of 11 compounds and the leaf extract showed the presence of 8 compounds. Both extracts contained chlorogenic acid and mangiferin. Hyperoside and quercetin were present only in the flower extract. In the TLC-DPPH. assay, almost all of the flower extracts and 5 compounds of the leaf extract showed radical scavenging potential. Estimation of phenolics and flavonoids showed that all the leaf extracts showed higher amounts of phenolics and flavonoids than stem extracts. Among leaf extracts, greater amounts of phenolics were detected in 50% aqueous methanol extract (261.25 ± 1.66 GAE/g extract) and greater amounts of flavonoids were detected in methanol extract (232.60 ± 10.52 CE/g extract). Among stem extracts, greater amounts of flavonoids were detected in the methanol extract (155.12 ± 4.30 CE/g extract). In the DPPH radical scavenging assay, the methanol extract of the leaf showed IC50 60.85 ± 2.67 µg/ml and 50% aq. methanol extract of the leaf showed IC50 63.09 ± 2.98 µg/ml. The methanol extract of the stem showed IC50 89.39 ± 3.23 µg/ml, whereas ethyl acetate and 50% aq. methanol extract showed IC50 > 100 µg/ml. In the antibacterial assay, the methanol extract of the leaf showed the inhibition zone of 12-13 mm and the stem extract showed the inhibition zone of 7-11 mm against S. aureus, E. coli, and S. sonnei, whereas both extracts were inactive against S. typhi. The findings of this study support the traditional use of this plant in Nepal for the treatment of diseases associated with bacterial infections. The present study revealed that the underutilized anatomical parts of H. cordifolium could be the source of various bioactive phytochemicals like other Hypericum species.